Home // About Us // Privacy Statement // Sponsorship Policy // Contact Us

Dr Michael Tronson's notes on Perioperative patient care








Disclaimer




These notes have been produced to assist the junior surgical staff at Box Hill Hospital Melbourne when caring for surgical patients throughout their perioperative course. They could be applied to all surgical disciplines. They are the thoughts and insights of an experienced anaethetist. They are not meant to replace standard textbooks, or local hospital policy. They are not specifically authorised by Box Hill Hospital or any other organisation. They have been prepared as a guide, not as an authorative text - and should be used as such.






Is health care a risky business?

Sipping a cup of coffee and seemingly unaware of the irony of what he was about to say, the registrar said; “The operation was a success, but he died two days later”.  According to a report from the Australian Patient Safety Foundation, one in ten surgical patients coming to an acute care hospital suffers harm because something predictable or preventable goes wrong during their stay. About three-quarters of all preventable deaths occur in patients over 65 years old.

Our job in Preadmission clinic is to prevent calamities. Our goal is to predict and prevent nasty surprises during the patient’s hospital stay and after they leave hospital.  To achieve this we need to evaluate our patients’ medical, physical and emotional states, optimize known diseases, identify occult diseases, predict likely postoperative problems, and take steps to prevent or manage them. Patient’s medication is frequently harming them. Other troubles occur because we fail to use effective treatments, and worse, give treatments that damage patients. Hospitals that follow guidelines save more lives. This is the reason for this book – to suggest some guidelines.

 

“First do no harm” – Hippocrates (460 –335 BC)

Important stuff

If you don’t diagnose it, you can’t fix it.

If you don’t predict it, you can’t prevent it.

Who is not suitable for elective anaesthesia?

· 

· 

·  Upper respiratory tract infection, chest infection or purulent sputum — wait 3 weeks.

·  Suboptimally controlled cardiac failure = can’t talk while walking down the corridor.

·  Untreated, unstable or suboptimally controlled diabetics (HbA1C >8.0%).

·  Unstable angina; meaning angina worse in the past 3 months, or occurring at rest.

·  Coronary stent within past 3 months (better to defer for at least 6 months).          + 50

·  TIA or stroke within previous 3 months (better to defer for at least 6 months).

·  Any infection where foreign material is to be implanted: hips, knees, vascular grafts.

What harms patients postoperatively

The majority of postoperative deaths occur in elderly patients with pre-existing cardiac or pulmonary disease who have undergone major surgery.

·  PACE = perioperative adverse cardiac events

o   Cardiac failure

o   Cardiac ischaemia

o   Sepsis

o   Renal failure

o   Haemorrhage

o   Pneumonia

o   Pulmonary emboli

 

Our aim is to get patients back

to their usual life as quickly as possible

 

An aside

Take nothing you see or hear for granted. Accept nothing you see or hear at face value. The most important clinical question you can ask yourself is  “Why did that happen?”  If you can’t find an answer then look it up, or ask someone. So much is known – so little is used. The most spectacular advance yet to be made in medicine will be to fully use existing knowledge.

Jargon

PACE  =  Perioperative Adverse Cardiac Event 

·  Arrhythmias.

·  Cardiac failure.

·  Acute pulmonary oedema.

·  Myocardial ischaemia.

·  Infarction.

·  Death.

ASA grading

ASA (American Society of Anesthesiologists) classification.  Anaesthetists use this shorthand to describe patient’s fitness.  Despite being written more than 50 years ago, the ASA grading is brilliant at predicting problems.

ASA I               Fit and well for age.

ASA II              Mild disease that does not hamper the patient enjoying daily activities.

ASA III             Severe disease restricting the patient’s daily activities.

ASA IV             Life threatening disease.

ASA V              Not expected to live another 24 hours without intervention.

ASA VI             Brain dead – organ donor

Major procedure (highly invasive surgery)

·  Expected to take more than 60 minutes.

·  Involves extensive tissue mass or  trauma.

·  Major disruption to body physiology persists after 24 hours.

·  Needs blood transfusion.

·  Involves a patient of ASA III grade or more.

·  All vascular surgery.

·  Major joint replacement.

·  Open abdomen or thorax including major laparoscopic surgery.

·  Intracranial or spinal operations.

·  Is an emergency.

Examples: aortic aneurysm repair, bowel resection, thoractomy, major joint replacement.

Minor surgery (moderately invasive surgery)

·  Procedure

·  expected to take from 30 - 60 minutes

·  Some tissue trauma.

·  Minor disruption to body physiology persists after 24 hours.

·  Patient is intubated.

·  No blood transfusion.

·  Laparoscopy.

Examples: inguinal hernia repair, laparoscopic cholecystectomy, prostatectomy.

 

“Wotcha mean minor surgery; it’s major surgery to me.”

Minimal procedure (minimally invasive surgery)

·  Expected to take less than 30 minutes.

·  Minimal tissue trauma.

·  No disruption to body physiology persisting after 24 hours.

·  Examples arthroscopy, D&C, cystoscopy.

Get the side and site of the surgery correct

Although it is rare a for surgeon to operate on the wrong side or the wrong site, mistakes are harrowing, heartbreaking and expensive.  Always PRINT the side of surgery in full, do not use abbreviations eg. don’t simply scrawl L.THR; print left total hip replacement.

Good 5 step regime

1.        On admission to hospital, ask the patient to mark YES on the site of the surgery with an indelible pen, and if on an extremity write no on the other limb.

2.        The ward nurse checks the patient’s pen mark before transfer to the OR.

3.        Check the pen mark again on arrival and admission to the operating theatre suite.

4.        The surgeon checks the patient's mark and confirms the site with an indelible marker.

5.        Don't induce anaesthesia until all these steps have been taken.

When to admit your patient

Admit on the day of surgery

·  As far as possible, admit all patients on the day of surgery.

·  Routine admission times are 06.30 for morning surgery or 10.30 for afternoon surgery.

·  Admit those with mental impairment on the day of surgery.  Organise for a person they trust to stay with them. 

· 

Admit the day before

Admit the following patients at 14.30 hrs the day before surgery:

·  Elective abdominal aortic aneurysms that require angiography or other investigations.

·  Insulin dependent diabetics for major bowel surgery with severe intercurrent disease.

·  Patient who require bowel prep the day before their procedure and who are:

o   Frail and live alone, and those >80 years;

o   Those likely to get postural hypotension if they become dehydrated;

o   Patients with CCF or IHD with METs score of 2 or less.

How to postpone a patient

Check category of patient on MR4 form.  Catergory 1 patients are urgent, and have to have their procedure within 28 days. Before postponing Category 1 patients discuss it with your consultant surgeon.  BHH is fined up to $30 000 if Cat 1 surgery is postponed unnecessarily. Inform the registrar, anaesthetist, and booking office.

Consent

Box Hill Hospital's policy on consent

The policy is set out in a document: "Box Hill Hospital Medical Services Policy Manual 2002".  If you have doubts about what you are doing then seek help from the head of your unit, or if not available then contact Clinical Services Administration.  There is always someone on call. Don’t get yourself into the situation where “Hizonor” might ask from the bench  “Oh I see doctor, and just how many pancreactoduodenctomies have you done?”

The minimum the patient needs to know

·  Diagnosis and prognosis.

·  Why the procedure is being done.

·  What will happen if nothing is done.

·  Options for anaesthetic and surgery.

·  Chances of success.

·  What tests are recommended and why.

·  Risk of the anaesthetic/operation.

·  Risks and benefits of blood transfusion.

·  How pain will be controlled.

·  How long the patient will be confined to bed.

·  How long is the stay in hospital.

Valid consent involves

For the consent to be valid and effective, the patient's consent must:

·  Be freely and voluntarily given.

·  Cover the procedure to be performed.

·  Cover the person who is to perform the procedure.

·  Be given by a competent patient capable of consenting.

·  Be sufficient to satisfy the patient while ensuring that no material risks are withheld.

This means that you must inform the patients of known risks when either a risk is rare but the outcome is severe, or the risk is common but the outcome slight.

Hints

·  Don’t consent a patient for surgery unless you are aware of the consequences of the surgery and the anaesthetic, and all the material risks. [Rogers vs. Whittaker 1992]

·  If you aren’t sure about all the material risks then refer difficulties to a more experienced senior colleague (that’s what they’re paid for).

·  Note in the record whether the patient appears to understand what you have said.

·  Ask your patient “Do you understand everything I have said to you?” 

·  Ask yourself:  “Do I know enough to stand in a witness box to defend my career?” 

·  Ask your patient to write down any further questions that arise when they get home. They can then resolve these queries when they are admitted for their operation.

b     Little gem

Never deprive someone of hope; it may be all they have.

 

·  Don’t say, “Good luck!” to your patients as they leave your office because some get really upset by this.  If you want to say anything say something like:”I hope it all goes well for you.”

Jehovah’s Witnesses and other sects

Jehovah’s Witnesses may consent to surgery and anaesthesia, but refuse a blood transfusion.  They have a sincere and deep religious objection to blood transfusion or receiving any blood products.  Fill-out the special consent forms for those who refuse blood, or blood products.  However, Jehovah’s Witnesses cannot refuse to consent for blood transfusion for relatives, minors, or friends.  It is futile to argue with the patient or their associates; refer difficulties to Medical Administration.

Minders

Some religious sects send 'minders' to accompany patients through the preadmission process.  Interview patients for at least part of the time, without their 'minders' being present.   Out of the earshot of their minder, the patient’s views may differ.  You can always invite their 'minder' to come in later.

Relatives

A similar problem occurs with relatives and friends.  If the patient asks: "Can my husband come in too?" usually means she is happy to have him present.   However if the husband asks, "Do you mind if I come in too?” then it is wise to seek the wife's consent out of her partner's earshot.  This particularly applies to older teenagers, and young adults accompanied by their parents. 

Interpreters

Box Hill Management Executive Committee Policy rules

·  Book interpreters well in advance.  This is best done from the waiting list when patients are first booked for their outpatients appointments.

·  Patients have a right to interpreters at all times.

·  The biggest risk of litigation or harm occurs if the health care worker fails to:

o   comply with the patient’s wishes;

o   obtain informed consent; 

o   to ensure patients understands what they have been told.

·  Where possible, use accredited medical interpreters. Do not use the patient’s friends or family, or any member of the hospital staff who is not a doctor or a nurse.

·  Make sure there is an orange coloured Interpreter Alert Sticker on the patient’s file.

·  Book an appropriate interpreter through the Eastern Health Transculural Services Unit. They have a good intranet site.

·  There are a number of telephone interpreting services. Box Hill Hospital uses Victorian Interpeting Telephone Service (VITS) – see the Eastern health Intranet for details.

Specific surgery

General surgery

Bowel resection

Colon and rectal cancer affects about 1:18 males, 1:24 females usually when elderly, with 9000 new cases each year in Australia.  Familial predisposition is about 1%.

Preoperative

Problems include: anaemia from occult blood loss, poor nutrition. Useful to start preoperative vitamin supplement, and consider nutritional supplements.  Check for pernicious anaemia. May need preop iron supplements.

Overall postoperative mortality is a 6.9 - 8.1%.  Independent predictors of death are age, ASA >II, Duke’s stage, urgency of operation. 

Operation

1.5 -  3 hours

Anaesthesia

G+A ± epidural

Cross-match

2 units

Pain

+++ if no epidural.

Nasogastric tube

Not usually

Urinary catheter

Yes

Hospital stay

6 -  8 days

Mortality

8 -  10% at BHH

Big risks

Postop hyponatraemia, postop hypoxia, sepsis, with ensuing cardiac problems.

 

Postoperative

Better to avoid blood transfusions with colorectal cancer because transfusion is an independent predictor of recurrence, or rapid progression of cancer.

6 – 8 litres of isotonic fluid transudates into the bowel resolving with diuresis on the 4th day.  Use at least 3 or more litres of Hartmann’s solution on the first and second day. 5% dextrose causes hyponatraemia. Check electrolytes the morning after surgery. Add 13.4 mmol potassium to alternate litres.

Sepsis on day 1 or 2 revealed by gradually rising respiratory rate, poor perfusion status, and possibly mild confusion. Patients over 70 years may not get febrile, or mount a white cell response.

On days 3 + hiccups are a sign of a blood or pus collection under the diaphragm (usually on the left side). Look for partial basal lung collapse in the left lower lobe (fuzzing out the medial few centimeters of the diaphragm), and fluid collecting in the pleural space obliterating the lateral angle of the diaphragm on the affected side.

Oesophagectomy – open

Preoperatively

·  A suboptimal nutritional status increases mortality and morbidity.

·  Chemotherapy causes further immunosuppression.

·  Get respiratory function tests, and arrange an elective admission to ICU. 

·  In patients > 45 years get an echocardiogram + EF

·  Make sure the patient brings all CT scans and X-rays with them.   

 

Operation

4 - 7 hours, long and often bloody.

Indication

Usually carcinoma, but occasionally stricture.

Anaesthesia

GA with mid thoracic epidural.  Needs one lung anaesthesia. 

Cross match

6 units

Lines

Pulmonary artery catheter, arterial line. thoracic and abdominal drains.

Nasogastric tube

Essential.  Crosses anastomoses. Must be stitched to nasal frenulum,. A disaster if this becomes dislodged in first few days.

Pain

++++

Urinary catheter

Yes

Intensive care

Yes, for at least 4 - 5 days

Hospital stay

12 - 14 nights

Mortality

< 6% in skilled hands, up to 50% in occasional operators

Big risks

Intraoperative hypothermia. High risk of aspiration About 25% get major complications especially PACE.  2/3 of deaths are from anastomotic breakdown leading to sepsis. 

Laparoscopic cholecystectomy 

10% of the adult Western population get gallstones, and 1-4% a year cause problems.

Operation

1 -  1.5 hours

Anaesthesia

G+A

Cross-match

G+H

Pain

++  particularly radiated to shoulder tips

Urinary catheter

No

Hospital stay

2  - 3 nights

Mortality

<0.1%

Big risks

Gas embolism, conversion to open operation, DVT, right lower lobe collapse, bile leakage causing peritonitis, bleeding.

 

Conversion to open surgery is more likely if  body mass index >35, previous abdominal surgery; gall bladder wall thickness >0.4 cm; ASA III or more; acute cholecystitis.

Insufflated gas irritates the under surface of the diaphragm (innervated by C3, 4, 5). Shoulder tip pain may feel as though “somebody has tried to rip my arms out” and responds to NSAIDs, or small dose of opioid.

High gastric reduction

Operation

1.5  - 2 hours

Anaesthesia

G+A

Cross-match

G+H

Pain

+++

Urinary catheter

Yes

Hospital stay

4 – 5 nights

Mortality

<1% but it depends on the mass of the patient. 

Big risks

DVT, aspiration, basal lung collapse, wound infection, abdominal hernia, anastomotic leak, failure,

From Jan 2007 add the following investigations: Zinc, chromium, homocysteine, fasting lipids, fasting glucose, fasting insulin, HbA1C, iron studies, B12, folate, TFTs.

Gastric banding - laparoscopic

Operation

1 – 1.5 hours

Anaesthesia

G+A

Cross-match

G+H

Pain

++

Urinary catheter

No

Hospital stay

1 night

Mortality

<0.1% but it depends on the mass of the patient. 

Big risks

DVT, aspiration, basal lung collapse, organ perforation, failure,

From Jan 2007 order the following additional investigations: Zinc, chromium, homocysteine, fasting lipids, fasting glucose, fasting insulin, HbA1C, iron studies, B12, folate, TFTs.


Haemorrhoids

Operation

15 - 45 minutes

Anaesthesia

GA or spinal

Cross match

Nil

Pain

++++ if no caudal anaesthetic is given

Urinary catheter

No

Hospital stay

2 - 3 nights

Mortality

Negligible

Abdominoplasty (apronectomy)

Indication

Flabbing abdominal fat apron

Surgery

1.5 -  2 hours

Anaesthesia

G+A

Cross-match

G+H - may need up to 2 units

Pain

+++

Urinary catheter

Yes,  usually - depends on weight of patient

Hospital stay

5 – 7 nights

Mortality

<1% but it depends on the mass of the patient. 

Big risks

DVT, aspiration, basal lung collapse, wound infection,

 

Splenectomy

Indication

ITP, Felty’s syndrome, trauma 

Operating time

60 - 90 minutes

Preop tests

platelet count.  Consult the haematologists, and the blood bank.

Anaesthetic

GA supplemented by epidural or intercostal blocks depending on the platelet count.

Blood transfusion

Cross-match 2 units for small spleens, up to 6 units for large spleens. Have 6 units of group specific platelets at hand.

Urinary catheter

No

Pain

+++++  without local blocks or epidural

Hospital stay

7 - 10 days

Special problems

postoperative chest infection, haemorrhage pain.

Postoperative:

Patient needs life time penicillin cover and you need to organise vaccination against pneumococcus, and meningiococcus.

Platelet transfusion

Order 6 units of platelets, because it may be necessary to top-up the patient’s platelets up once the spleen is clamped during surgery . The spleen gobbles platelets lightning fast.

Thoracic surgery

Sternal split

Surgery

1 - 1.5 hours

Anaesthesia

General anaesthesia

Cross-match

2 units of blood are needed for a large sternal split

Blood loss

600 - 800 ml

Drains

Possible thoracic drain if pleura breached

Pain

+++

Urinary catheter

No

Hospital stay

5 days

Mortality

<0.1%

Big risks

Airway obstruction, vocal cord paralysis, laryngeal incompetence and nausea and vomiting.

 


Lung resection

Preop need

·  Physiotherapy referral

·  Those with major symptomatic cardiac disease, reduced pulmonary functions who are dyspnoeic when walking on the level, are likely to die after operation.

·  Patients with < 4 METs are at high risk of postoperative complications.

 

Surgery

1.5  - 2 hours

Preop needs

·  Minimum preoperative FEV1/VC (age corrected) are:

Pneumonectomy                        >55%

Lobectomy                               >40%

            Wedge resection                       >35%

Anaesthesia

General anaesthesia + thoracic epidural

Cross-match

2 units of blood are needed for a large sternal split

Blood loss

600 - 800 ml

Drains

Thoracic drain

Pain

++++ controlled with thoracic epidural

Urinary catheter

Yes

Hospital stay

7 – 10 days

Mortality

1 %

Big risks

postoperative chest infection, pain, dermatomal neuralgia.

VATs Pleurodesis 

Involves stripping of parietal pleura from inside chest and instillation of talcum powder to ensure lung stays inflated.  Used for repeated pneumothorax in young asthmatics, and elderly with recurrent pleural effusions.  If pleural effusion >50% then drain first.  Patients with < 3 METs are at high risk of postoperative complications.

 

Surgery

1.5 hours 

Preop needs

Physio referral, recent chest X-ray. Discuss analgesic options

Anaesthesia

General anaesthesia +/- thoracic epidural

Cross-match

2 units of blood are needed for a large sternal split

Blood loss

600 - 800 ml

Drains

Thoracic drain

Pain

+++++   controlled with either pleural catheter or thoracic epidural

Urinary catheter

Yes

Hospital stay

3–4 days

Mortality

<1 %

Big risks

postoperative chest infection, pain, dermatomal neuralgia.

Needs chest X-ray in recovery room to check that lung is fully expanded.

Vascular surgery

Abdominal aortic aneurysms (AAA)

Operation

2.5 – 4 hours

Anaesthesia

general + epidural

Cross-match

4 units

Pain

+++   controlled with with epidural. 

Urinary catheter

Yes

Hospital stay

10 –12 days

Mortality

1%

Big risks

postoperative hypoxia with MI on day 2

Medication

Consider preoperative beta-blocker

Without operation risk of rupture increases with aneurysm diameter:

·  4 - 7 cm   = 25% risk.

·  7 - 10 cm = 45% risk.

·  >10 cm 60% risk.

·  Mortality rate for ruptured aneurysm at Box Hill Hospital is about 50%. 

Risks

Risks of myocardial infarction postoperatively is about 5%, with a 50% mortality.  Coronary artery plaque rupture is a major cause, but also the heart needs to increase its output considerably in the first few days after surgery. and this in itself may cause ischaemia.

Infra-inguinal vascular surgery

Operation

2.5 - 4 hours

Anaesthesia

general or spinal/epidural

Cross-match

2 units

Pain

++

Urinary catheter

Yes

Hospital stay

10 days

Mortality

2+%

Big risks

postoperative hypoxia. At least 6% risk of MI on day 1 or 2

Medication

preop beta-blockers

Carotid endarterectomy (CEA)

Usually performed on patients with > 70% stenosis of internal carotid artery with symptoms.  Once artery is totally blocked, operation is not required.

Operation

2 – 2.5 hours

Anaesthesia

usually general anaesthesia

DO NOT STOP ASPIRIN

Cross-match

G+H

Pain

+1

Urinary catheter

No

Hospital stay

4 days, and then to rehabilitation

Mortality

1%

Big risks

Postoperative stroke, and hypoxia at night with MI on day 2

Urology

Cystoscopy

Day case.  Diagnostic flexible cystoscopy under local. 

Rigid cystoscopy spinal or GA. 

Operation 5 - 10 minutes. 

Cystoscopy and resection of bladder tumour (TURBT)

·  Overnight stay.

·  Anaesthetic: general.

·  Operation 15 - 25 minutes.

·  Catheter if tissue resected.

Radical prostatectomy

·  Urine micro and culture, FBE, U+Es, liver function tests, ECG, CXR. 

·  Cross-match either 2 units of autologous blood, or 3 units of homologous blood.

·  Reinforce preop pelvic floor contractions held for 14 seconds 10 times per day.

·  Fit venous compression stockings. 

·  Arrange Hospital-in-the-Home after operation: continuation of pelvic floor exercises,

 

Operation                      1 - 1.5 hours

Anaesthesia                  general supplemented with continuous epidural

Cross-match                 4 units of blood

Blood loss                     1500+ ml

Pain                             ++       

Urinary catheter yes

Hospital stay                  5 days

Mortality                        2%

Big risks                       Postoperative hypoxia especially at night, urinary obstruction, DVT,                                              incontinence.

Total cystectomy ± ileal conduit

Preoperatively:

·  Note any previous chemo or radiotherapy.

·  Make sure current CT scans available and that the patient brings them to hospital.

·  Check tissue biopsy is confirmed.

·  Tests include FBE, U+Es, LFTs and MSU

 

Operation                      4 - 7 hours

Anaesthesia                  general supplemented with continuous epidural

Cross-match                 4 units of blood

Blood loss                     1500+ ml

Pain                             ++        usually controlled with epidural   

Urinary catheter yes

Hospital stay                  7 - 10 days

Mortality                        2%

Big risks                       Postoperative hypoxia especially at night, urinary obstruction.

                                    DVT

Extracorporeal shock wave lithotripsy (ESWL)

·  Plain X-ray to show position of stone.  ECG.  U+Es, FBE, LFT.

·  Give patient to take withthem: photocopy of relevant outpatient notes, container for stone debris, “Stone diet” instructions, BHH review appointment for 3/52 with prior kidney U/Sound.  Completed consent form, unreported current X-ray of stone.

·  Patient to fast from midnight the night before and present to St.  Vincent’s Hospital at 7.00 am on the day of procedure, with all their results.

 

Operation

1 hour

Anaesthesia

epidural or sometimes general anaesthetic

Cross-match

G+H

Blood loss

Minimal

Pain

++

Urinary catheter

Yes

Hospital stay

Day case, done at St.  Vincent’s Hospital

Mortality

Rare

Big risks

urinary obstruction from debris, bleeding, failure, systemic sepsis.

If the procedure is complicated they will be admitted to BHH Urology Ward on that afternoon.  If stents need later removal then book for this procedure at BHH. 

TURP = transurethal resection of the prostate. 

·  The aim is to resect the prostate tissue, but spare the prostatic capsule. 

·  Use prostate ultrasound to find the size and uniformity of the prostate. 

·  Prostates >100 gm usually need an open (Miller’s) prostatectomy.

Preoperative

·  Tests: Urine micro and culture because incidence of bacturia about 40%. 

·  FBE, U+Es, liver function tests,

·  ECG.  CXR. 

·  If haematuria then get a renal ultrasound. 

·  Stop aspirin 7 days prop and recommence 5 days postop

Operation

20 - 40 minutes

Anaesthesia

Spinal

Cross-match

G+H

Blood loss

200+ ml

Pain

+

Urinary catheter

Yes

Hospital stay

4 nights

Mortality

1%

Big risks

Postoperative hypoxia especially at night, urinary obstruction, TURP syndrome, glycine toxicity, sepsis

Postoperative

·  Patients may absorb large amounts of irrigation fluid during the procedure. 

·  If they already have peripheral oedema this will exacerbate their fluid overload and they may develop pulmonary oedema. 

·  Make sure hat peripheral oedema is as well controlled as possible before TURPs, even if it means postponing the procedure for a couple of weeks.

Risks

Bleeding needing transfusion, re-operation, conversion to open operation, permanent stress or urge incontinence 15%, long term catheter, impotence 5%.  Retrograde ejaculation 100%, sex feels different 100%. Mortality <1%, success rate 85+%, recurrence <15%.  Hypothermia, clot-retention with 3-way catheter for 24 - 36 hours.  The operation is done under spinal anaesthesia with minimal sedation so that TURP syndrome 1% can be diagnosed early.  Transient blindness secondary to glycine absorption.

Orthopaedic surgery

Hip replacement (THR)

Preop.

Need to achieve a MET score of 3.

 

Operation

2.5 – 4 hours

Anaesthesia

Usually spinal + sedation. Redo needs GA

Cross-match

3 units

Pain

++    (little if they have PCA)

Urinary catheter

No

Hospital stay

4 – 6 days and then up to 1 month in rehab

Mortality

1%

Big risks

DVT /PE, postoperative hypoxia with MI on day 2,

Bone dust and trash emboli ends up in the lungs after joint replacement. This causes episodic hypoxaemia at night for upt to 8 days. The SaO2 may dip below  “safe” limits of 92%. Order mandatory oxygen supplement, especially in those receiving opioids. It only takes a few minutes of hypoxaemia to scramble an older persons brain - permanently.

 

Oxygen is cheaper than nursing home care.

Total knee replacement (TKR)

Preop.

Need to achieve a MET score of 3.

 

Operation

2.5 – 4 hours

Anaesthesia

Usually spinal + sedation. Redo needs GA

Cross-match

1 unit if patient weighs < 55 Kg

Pain

++    (little if they have PCA)

Urinary catheter

No

Hospital stay

4 – 6 days and then up to 1 month in rehab

Mortality

1%

Big risks

DVT /PE, postoperative hypoxia with MI on day 2,

Bone dust and trash emboli ends up in the lungs after joint replacement. This causes episodic hypoxaemia at night for upt to 8 days. The SaO2 may dip below  “safe” limits of 92%. Order mandatory oxygen supplement, especially in those receiving opioids. It only takes a few minutes of hypoxaemia to scramble an older persons brain - permanently.

 


Investigations

We waste staggering amounts of money on unnecessary investigations. A routine CXR, FBE, U+Es + LFTs cost >$100. Of the 4000 patients a year we review in preadmission clinic less than 1% of otherwise well people return worrying results.  Nevertheless, chronic kidney disease (CKD) is under diagnosed, and this causes unnecessary misery. Those most at risk of CKD have hypertension, diabetics, or other vascular disease.

Use your clinical acumen to select investigations.

Nursing observations

The nursing staff in Preadmission Clinic routinely record height, weight, oxygen saturation, peak flow, blood pressure, urine analysis, and in diabetics a blood glucose (finger-prick).

Routine preoperative investigations              

·  FBE, in patients older than 65 years unless done recently.

·  U+Es if patient has diabetes, hypertension (treated r untreated), cardiac failure, or has known renal disease. Allso those taking drugs excreted by the kidney (digoxin) or those that could damage the kidney (NSAIDS, COX,

· 

·  Add LFTs if the patient:

·  has intercurrent disease that might affect the liver,

·  is on medication affecting the liver including statins, antimetabolics (methotrexate), herbal remedies

·  drinks > 3 – 4 units of alcohol daily

·  surgery is expected to take >60 minutes,

·  or was born or have lived outside developed countries (Hep B, & C).

·  Hypothyroidism is common in the elderly.  They feel the cold – “something awful”. Consider TSH in female patients over 60 years;

 

Test

ASA I

ASA II

ASA III

ASA IV

FBE

 

+

+

+

U + E

 

+

+

+

Creatinine

 

+

+

+

LFT

 

+ (if on medication)

+

+

ECG

 

+

+

+

CXR

 

 

+

+

 

ECG

Write helpful stuff on the ECG form especially blood pressure, any cardiac, or psychotropic drugs, IHD or CCF. 

Order ECGs for anyone with:

·  History of actual or possible heart disease,.

·  Hypertension.

·  Diabetes.

·  Vascular disease.

·  Obesity BMI > 30.

·  Men > 40 years.

·  Women > 45 years unless ECG in previous 2 months.

·  All smokers aged 35 years or more. 

CXR

Be kind to a radiologist:

· 

·  Radiologists aren’t mind readers, so write useful things on their forms too.

·  Don’t annoy them by writing “routine preop CXR”, or infuriate them by writing nothing.  

·  Don't double radiation radiation dose with lateral CXR unless there is a good reason.

·  Don’t order routine chest X-rays in asymptomatic patients:

·  who are under the age of 70 years;

·  who are undergoing minor surgery;

·  who are life long non-smokers;

·  with a previously normal chest X-ray in the past 5 years;

·  asthmatics (unless you think they have pneumothorax);

·  fertile women.

·  Do order a CXR in patients who have:

·  smoked for 5+ years at any time and are now >55 years of age;

·  a history of cardiac failure;

·  cancer anywhere. 

Other indications for CXR include: deviated trachea, recent onset of hoarse voice, haemoptysis, hacking dry cough, suspected mediastinal masses, persistent crackles in lung bases, cardiac enlargement, or dextrocardia.

Liver function tests

Order LFTs if there is evidence of previous or current liver disease, the patient is taking medication that potentially can damage livers, or if major surgery is planned.  Consider LFTs if patients were born or have lived outside developed countries and may have Hep B or C.

`                Physiological foundations

·  Liver function tests do not test liver function; they test liver damage (“transaminitis”).

·  ALT is the most specific marker; it is released as liver cells die. 

·  AST is not specific for hepatocyte death; it also occurs in heart muscle. 

·  Alkaline phosphatase is also found in bone; it accumulates in the blood when cells lining the biliary tract are damaged. It is excreted by the kidneys.

·  The bile duct releases GGT when exposed to certain toxins (eg. drugs, alcohol).

Medical imaging

Radiation is hazardous

,          Fast facts

· 

· 

·  A total body CT scan gives almost the same dose of radiation received by Hiroshima victims standing in the open about 2 km from the blast - equivalent to 500 times the dose of standard chest X-ray. There is a 1 in 1200 chance of it causing cancer.

·  About 3 millisieverts a year come from background radiation.  The annual maximum radiation dose should not be greater than one additional millisievert.

·  Every radiological investigationscarries a small risk. There is probably (but some studies show “not definitely”) no safe level of exposure.

·  A CXR gives 20 µSeiverts (1/50th of the maximum permitted additional annual dose).

·  Avoid any X-ray unless absolutely essential in fertile or pregnant women.

 

Investigation

= Number of CXR

 

Investigation

= Number of CXR

Abdominal X-ray

75

 

Lumbar spine X-ray

120

Thoracic spine X-ray

50

 

Barium swallow

100

Preop cholangiogram

65

 

Ultrasound of abdomen

0

CT of abdomen

400

 

Spiral CT of abdomen

300

MRI of abdomen

0

 

Arteriogram of leg

400

Renal arteriogram

80

 

Thyroid isotope scan

6

About magnetic resonance imaging

 

The MRI uses gigantic magnetic fields.  Any metal (even a tiny fragment) either glows red hot, or is torn out of tissues.  So check for pacemakers, brain aneurysm clips, cardiac clips, staples, cochlear implants, neuro-stimulators, metal in the eye (arc welders, metal workers), metal pins, plates, rods, hip or  knee replacements, hearing aids, shrapnel or bullets, dentures, teeth fillings or braces, tattooed eyeliner, wigs.  

So what’s “normal”?

The range of normal values quoted by laboratories follows a bell-distribution curve and includes 95 per cent of the healthy population, but 5% will still be 'normal' even though the results lie outside the “normal range”. 

When ordering tests, avoid a scattergun approach. 

 Select your targets precisely.

Don't order!

Don't order routine blood sugars

 

Routine blood glucose levels are waste of time in patients who aren’t diabetic.  To diagnose diabetes you need, either a blood glucose >11 mmol/L with signs and symptoms of diabetes, or  on two separate occasions a blood glucose >7 mmol/L after an overnight fast.

Don't order routine clotting studies

Don’t order routine coagulation profiles profiles unless their is a reason to do so such as a history (or family history) of bleeding or clotting disorder, is on warfarin, or is undergoing vascular surgery where heparin may be used. 

As the Royal Australasian College of Pathologists so neatly says: “The combination of an aPTT and an INR as ‘screening tests’ do not reliably detect mild, but clinically important, bleeding disorders; in contrast the sensitivity of clinical assessment is high.  (This means you need to ask about bleeding, and look for bruises.)  These tests have little place in the preoperative assessment of patients; as routine tests they are inappropriate and in a patient with a positive history, they may well be inadequate”. 

Don’t order routine troponin T levels

·

Troponin T is a highly sensitive test for acute myocardial cell death. It rises for 3 - 4 days after the death of myocardial cells.Troponin levels do not detect ischaemia. 

VOMIT = victims of medical investigative technology.

Thallium/dipyridamole scans cost > $1200.  They have high sensitivity (80%) and high specificity (90%) for detecting coronary artery disease, but in patients who are at low risk of ischaemic heart disease their  predictive value of the test is only about 30%.  This means 70% of of those you investigate will return false positives.  These unfortunates will then be sent off for unnecessary coronary angiography.  Since coronary angiography carries a one per cent mortality, it is possible to kill a perfectly healthy person.


Special cases

Diabetics need                                                         +         81

· 

·  Random blood glucose.

·  HbA1C.

·  TSH unless done in the past year.

·  For newly diagnosed Type II (NIDDM) consider iron studies to exclude haemochromatosis.

·  At some stage, a blood lipid screen.

Patients with ischaemic heart disease             +          48

Investigate ischaemic heart disease only if you would do so had the patient NOT presented for surgery. Patients with stable IHD who have been investigated within the past 5 years need no further follow-up.

Patients with heart failure need                               +          57

·  CXR.

·  ECG.                                                                                     

·  If the patient has had worsening symptoms in the past 6 months then order echocardiography, including a request for ejection fraction or fractional shortening.

·  First check that the patient is suitable for echocardiography.      +        64

What cardiac investigations in order of preference

·  Stress echocardiography — if suspect cardiac failure;

·  or dopamine stress echocardiography — if unable to exercise;

·  or thallium/dipyridamole scan — if unable to exercise or very fat, or have left bundle branch block, WPW or a pacemaker, or cannot lie on the left side.

·  Pacemakers                                                                           +             57       

·  Valve replacements                                                                 +             63

Epileptics need                                                        +             88      

· 

·  LFTs because anti-epileptic drugs can damage liver cells.

·  Check ECG for QT-interval >440 msec - a side effect of some anticonvulscents.

·  Check platelets; valproate, carbamazepine, or ethosuxemide can cause thrombocytopaenia.

Thyroid disease                                                       +             96

· 

·  Thyroid function tests.  Order a TSH only.  If the TSH is abnormal the lab will proceed to do free T4 and T3.  Thyroid binding globulin assays are no longer done.

·  Thoracic inlet CT or ultrasound if hoarse voice or stridor.

·  Particularly in women >45 years check their TFTs if any hint of hypothyroidism including tiredness, lethargy, feels the cold.

Recent bleeding, anaemia or bruising disorder       +             37

· 

·  Full clotting studies (consult haematology registrar).

·  Iron studies include Fe++ iron binding, ferritin and transferrin, B12 and folic acid.

Who needs respiratory function tests                     +             70

· 

·  Patients with respiratory disease who can walk up 2 flights of stairs without being breathless when they reach the top are probably fit for most surgery.

Order respiratory function tests in patients with:

·  exercise limiting lung disease in those having upper abdominal or thoracic surgery;

·  if the patient requires ICU respiratory support postoperatively;

·  lung resection or invasive open thoracic surgery such as oesophagectomy.

What to do with smokers                                         +  67

Order a CXR if patient has smoked for more than 5 years at any time and:

·  is now >55 years of age,

·  has persistent cough with or without sputum. 

·  If there is coloured sputum then they also need:

·  sputum micro and culture;

·  referral to their LMO for bronchodilators, and antibiotic therapy .

Medication

What medication to take on the day of surgery

Do take: cardiac medication. blood pressure therapy, antiepileptic medication. thyroxine, and anti-ulcer drugs.

Do not take: NSAIDS, potassium supplements, biphosphonates, diuretics, or cytotoxics.

How to instruct patients about their medication

More than 20% of our adult patients can’t read the simplest instructions, so use the traffic light system.  Put red stickers on the packets of the medications patients must stop, and green stickers on the packets those they should take on the day of surgery.  To ensure proper absorption and reduce gastric acidity ask your patient to take their tablets with a full glass of water (not a just sip).  Water exponentially clears the stomach.with more than half gone within 12 minutes and it is completely cleared in <50 minutes.

Cautions with other medication

·  Anticoagulant                                                                                                +  31

·  Aspirin: stop 4 days before most surgery, 7 days before urological surgery, and 14 days before neurosurgery.  Do NOT stop before vascular surgery              +  31

·  COX inhibitors: stop them at least 4 days before surgery.                                 +  32

·  NSAIDs: Cause perioperative bleeding, renal impairment, and fluid retention.  Stop them at least 4 days before surgery, especially in patients >65 years, or if you anticipate blood transfusion or fluid loss.                                                            + 32

·  Diabetic medication. Stop oral hypoglycaemics on day of surgery. Note there are special situations where metformin needs to be stopped earlier.                         + 81   

·  Epileptic medication - important to maintain on day of surgery.

·  Natural remedies: Stop at least 7 days before anaesthesia. Many cause bleeding.

·   

·  Psychotropics: stop moclobemide (Aurorix®) a full 24 hours before surgery.  If the patient is taking one of the scary MAOI Group A drugs (tranylcypromine (Nardil®) or phenelzine (Parnate®) ) then consult an anaesthetist.  Don’t stop SSRIs, TCAs, phenothiazines, benzodiazepines, or others, but do tell the anaesthetist, because these drugs adversely interact with anaesthetic agents. 

·  Stop iron tablets 4 days before colonoscopy. Iron tablets leave little rust marks on the wall of the large bowel., which can be mistaken for petechia or haemorrhage.

Statins and drugs for dyslipidaemias

·  Do not stop statins. Statins stabilise plaque in vascular patients, those with ischaemic heart disease, and particularly those with coronary stents that have been inserted in the past year.

·  If a patient is taking a statin + gemfibrozil or high dose nicotinic acid, then maintain the statin and stop the others for 4 days preop. 

·  Watch for postoperative rhabdomyolysis in patients taking statins who are septic, women with a body mass index <19, or who are elderly, and following major tissue destructive surgery (eg. total hip replacement), or where tourniquets have been used. Those at risk may already have a raised CPK before surgery. 

·  Rhabdomyolyis causes the urine to look as though it contains blood - it is myoglobin (it looks red because myoglobin is the alpha chain of haemoglobin).

 

What are the land-mines with medication?

·  Patients are clearly asked in writing to bring ALL their medication, (absolutely everything) with them when they come for Preadmission assessment.  If they don't then suspect: dementia, illiteracy, cognitive problems.

· 

·  Don’t trust that list of drugs produced from their shopping bags.  Patients often forget to tell you about their puffers, eye drops, creams, herbal remedies and vitamins. 

·  Check the dispensed date on the drug label - many are out-of-date. 

·  Different medications from different doctors?  Suspect doctor hopping or shopping.

·  75% of patients fail to take their medication, or take the wrong dose, or use alternative remedies not prescribed by a doctor. Phone the GP and discuss the problems with him. 

·  40% take either inappropriate medication, or are suffering from side effects.

What to do about patients on chemotherapeutic agents

Liaise with the physicians if your patient is taking any of these: bleomycin, vincrisitine, 

Azothioprine

·  Azothioprine is a toxic drug.  Stop 7 days before surgery. 

·  Possible agranulocytosis with nitrous oxide. 

·  Delays wound healing, risk of infection.

·  Potentially fatal bone marrow depression with trimethoprim, allopurinol, rifampacin and barbiturates.  Check white cell count 4 days after surgery. 

·  Antagonises warfarin.  

Cyclophosphamide

·  May cause hyponatraemia secondary to inappropriate water retention.

·  Inhibits plasma cholinesterase synthesis.

·  Bone marrow suppression is severe.

·  Consider avoiding nitrous oxide because bone marrow failure may occur.

Lefunomide  and methotrexate

·  Used to treat malignancies, rheumatoid arthritis, SLE and psoriasis.

·  If taken once a week these drugs do not interfere with healing.

·  If you stop it then the inflammatory process may flare out of control.

·  If you maintain it, then avoid nitrous oxide because of risk of agranulocytosis. 

·  Check liver function.

·  Excreted solely by kidney so with renal impairment there is a risk of toxicity. 

·  Excretion is delayed by high dose penicillins and cephalosporins.

Careless prescribing fills graveyards

·  The Australian Patient Safety Foundation reports doctors are killing about 5000 people in Australia each year. (cf. National road toll < 2800).

·  Don’t use trade names.  Drug companies spend gadzillions to get you to order Lasix® rather than frusemide. Once they have got you, then they have your patient donates to their coffers for years to come.

·  If do not know the generic name, then you don't know enough about the pharmacology of the drug to safely prescribe it. Your are unlikely to prescribe two ACE inhibitors (suffix ...pril) but it is easy to slip up and say prescribe Amprace® and Vasotec®, or Plavix® and Iscover®  Don't smile - it happens - often! 

·  Don't prescribe a drug unless you understand its pharmacology and especially are aware of its interactions.

Preadmission an opportunity to check drug interactions

Our surgvey shows that 79% of patients over the age of 65 years attending Preadmission clinic are taking either inappropriate medication or are taking their medication inappropriately.  Many patients are being made sick by their medication. 

Common problems include:

·  Incompliance - oh so very common!  Check the expiry dates on the packets.

·  Using NSAIDs for non-inflammatory osteoarthritis when paracetamol is just as effective with fewer side-effects. .

·  NSAIDs aggravate cardiac failure, hypertension and renal impairment.  Very common in the elderly.  Beware of the longer acting naproxen and piroxicam. or the less specific ones indomethacin and ibuprofen.  Diclofenac is probably safer. Meloxicam and celecoxib aren’t innocent either..

·  Low dose aspirin + allopurinol a dastardly duo.  Even low dose aspirin totally nullifies the effects of allopurinol by stopping the renal tubules excreting uric acid.  .

·  Even low dose aspirin totally negates the gastroprotective effects of celecoxib - a futile expensive combination.

·  Elderly patients (>75 years) taking SSRIs.  Efficacy is debatable and a frequent cause of confusion and falls.

·  Patients with Parkinson’s disease taking SSRIs - aggravates the Parkinson’s.

·  SSRIs + tramadol - increased risk of seritonin syndrome.

·  Digoxin’s frequent side effects -> trouble with concentration, fatigue, confusion and even psychosis.

·  Sedative medication in patients with sleep apnoea can kill.

Elderly have extra problems with their medication

About 4% of elderly patients take more than 20 different medications every day (50+ tablets a day). The risk of inadvertent interactions, and adverse effects rises exponentially with the number of drugs used. Ironically some patients are taking even more drugs to offset the bad effects of other medications eg. NSAIDs increasing the need for protein pump inhibitors or diuretics.  Drugs with similar actions on receptors have a snowball-effect causing problems.  I recently saw a patient who needed admission to treat the combined cholinergic effect of prochlorperazine (phenothiazine), + amitriptyline (antidepressant) + antiarrhythmic (disopyramide) which had dried up his mouth (gum disease), dammed-up his urine (retention), clogged up his guts (constipation), and sent him mad (delirium).

Questions to ask older patients

·  Do you ever forget to take your medication?

·  Do you stop taking your medication if you feel worse?

Herbals and vitamins

(       Fast forward

Stop all herbal remedies at least 4, and preferably 7, days before surgery.

Herbals

·  CAM = complimentary or alternative medication.  Most patient’s won’t fess-up to using them. CAMs arecommonly used by women between ages of 25 and 60 years, and the elderly >60 years of both sexes.  CAMs, although “natural” may not be innocuous - cyanide, arsenic and strychnine are natural compounds. 

·  Plants produce toxins so that animals won’t eat them.  Animals counter-attack by developing CYP enzymes in their livers and gut to combat the toxins. For instance: onions and chocolate are lethal to dogs – they do not have the right CYP enzymes.

·  The eight most commonly used CAMs are: glucosamine, fishoil, ecchinacea, garlic concentrate, gingko, ginseng, valerian,

·  Aggravate bleeding: St John’s wort, glucosamine, evening primrose, fish oil, fever few, garlic concentrate, gingko balboa, meadow sweet, celery seeds, echinacea.

·  Abruptly stopping valerian may trigger a benzodiazepine withdrawal syndrome with the patient getting the “heebie-jeebies” (dysphoria = agitation, restlessness and profound feelings of unease).  “Gee Doc, I don’t know what is wrong, but I feel jittery, scared, sweaty and awful.

·   

·   

Vitamins

·  Vitamin E > 400 units/day -> bleeding, and reduces survival in patients with IHD.

·  The urine of Australians taking vitamins is almost worth distilling to recover them.  In Australia, except for those on bizarre diets, vitamin deficiency is not a problem.

·  Having said that scurvy is a real problem in elderly people and in older smokers.  There is a lot of vitamin D3 deficiency; it’s serious, and it’s preventable. In young children D3 deficiency causes rickets, and in the elderly it is called osteomalacia (often mistaken for osteoporosis). Veiled women are at exceptional risk. Thiamine deficiency occurs in alcoholics, and cancer patients who don’t eat.  Folic acid deficiency is a major problem in alcoholics, pregnant women (who need lots more), and those people with hyperhomo-cysteinaemia (an endothelial poison). B12 deficiency (occurs in 20% of people >80 years), and in vegans. This is sad, because the dementia and posterior spinal column damage is totally preventable.

The patient on steroids

Some patients are taking steroids, usually prednisilone, and occasionally dexamethasone. Patients who are, or have been, on oral or even inhaled steroids within the last 12 months may have adrenal suppression and be unable to produce enough cortisol to meet all the demands of surgery.

(       Fast forward

·  If your patient takes in excess of 7.5 mg prednisolone daily or its equivalent then use perioperative supplemental IV hydrocortisone. 

                        Minor surgery    hydrocortisone 25 mg daily for 1 day

                        Major surgery    hydrocortisone 25 mg QID for 3 days

·  Start oral steroids one dose before fully withdrawing the intravenous dose. There is no need to wean patients with reducing doses of IV steroids.    

·  If a patient is taking <7.5 mg of prednisilone (or its equivalent) a day, then they are unlikely to need perioperative corticosteroid supplements.

Equivalent doses

 

Equivalent dose

Duration (hours)

Cortisone 100 mg

=  80 mg hydrocortisone

=  20 mg prednisilone

 =  16 mg triamcinolone

=    4 mg dexamethasone

=    2 mg betamethasone

8 – 12

12 – 36

 12 – 24

36 – 72

36 – 72

`      Physiological foundations

·  Lack of

·  Lack ofcorticosteroid supplements when they are needed causes hypotensive that does not respond to any vasopressor.

·  Smooth muscle cells need cortisol to replace worn-out noradrenaline receptors in arterioles. Without cortisol, arterioles run out of noradrenaline receptors.

·  Without receptors the blood pressure begins to fall. No matter how much noradrenaline is secreted by adrenergic nerve ending, with no receptors, nothing is going to happen until the patient has received intravenous hydrocortisone. 

·  During the stress (catabolic) phase of injury large amounts of cortisol are secreted by the adrenal gland, and continue to be secreted until the catabolic phases is over. 

·  If you are unsure if the stress (catabolic) phase of injury is over, then measure urinary sodium concentrations.  This is a very sensitive test.  A urinary sodium excretion >70 - 100 mmol/L means the stress phase is over, and the patient is not unduly stressed.

·   

·  b    Little gem about urinary sodium

·  Urinary sodium rises and falls with physiological stress in parallel with cortisol levels.

·  It is useful as an ESR of surgery. 

·  Normal is 70 – 140 mmol/L

·  Post surgery it is about 10 – 20 mmol/L

·  Urinary sodium < 10 mmol/L suggests a highly stressed patient

·  If urinary sodium falls after it has started to rise then consider infection, hypovolaemia, and/or cardiac failure.

Eye drops

Beta-blockers

·  Betaxolol, levobunolol or timolol used to control chronic open angle glaucoma are absorbed, and exacerbate asthma or precipitate heart failure in predisposed patients. 

·  In the elderly they are may cause falls. 

·  If they are not causing problems they can be used as normal on the day of surgery. 

Ecothiopate

·  Anticholinesterase drops are still used for glaucoma and after cataract surgery. 

·  Delays the breakdown of suxamethonium, for up to 45 minutes.  Inform anaesthetist.

Psychotropic drugs

Antidepressants

· 

·  Tricyclic antidepressants (TCAs) - don't stop

·  Serotonin reuptake inhibitors (SSRIs) - don't stop.

·  Monoamine oxidase inhibitors (MAOIs) - don't stop, but avoid pethidine, tramadol.

·  Lithium - don't stop, but get levels and check renal function. avoid butyrephenones.

·  Venlafaxine – atypical SSRI – don’t stop, avoid pethidine, tramadol, droperidol.

·  Valproic acid - don't stop.

Antipsychotics:

· 

·  Benzodiazepines - don't stop, but be ready for acute withdrawal problems after operation.

·  Buspirone - little data available, but don't stop.

·  Butyrophenones - don't stop, but wean off in elderly patients taking it as a "sleeping tablet", avoid metoclopramide and lithium.

·  Olanzapine - don't stop, but avoid pethidine, tramadol.

·  Phenothiazines - don't stop, but avoid metoclopramide.

·  Quetiapine - don't stop, but avoid tramadol and pethidine.

·  Risperidone - don't stop, but avoid tramadol and pethidine.

·  Zaprazadone - don't stop, but avoid tramadol and pethidine.

·  Zolpidem - don’ stop. But not recommended for long term use.

·  Most of these antipsychotics ® prolonged QT-syndrome with the risk of torsade de pointes.  Check serum magnesium levels if the QTc interval on the ECG >440 msec.

NSAIDs

·  Safest to stop all NSAIDs at least 4 days before surgery, especially in patients >65 years, diabetics, hypertensives, or where you anticipate blood transfusion or fluid loss.  NSAIDs combined with SSRIs increase the risk of perioperative bleeding up to 15 fold.

·  NSAIDs slow renal blood flow to a trickle, especially if your patient becomes hypovolaemic.  They also stop platelets aggregating and so delay blood clotting. During and after surgery they can be bad news esepecally if patient is > 65 years. The outcome is perioperative bleeding, renal impairment, and fluid retention.  Some are long acting (piroxicam and naproxen

·  Preoperatively renal impairment is common in the elderly patient. Many people are unwittingly taking a combination of ACE inhibitors + NSAIDs  + frusemide = The triple whammy. This is proven recipe for renal dysfunction.  A guaranteed recipe for postoperative renal failure is to serve up a small dose of NSAID (or aspirin), a portion of ACE inhibitor, stir in a diuretic, simmer for an hour or so under anaesthesia and then garnish with a dose of gentamicin (or even a penicillin).

·  NSAIDs are potent cause of cardiac failure and are responsible for 10% of admissions to hospital for CCF. They aren’t good drugs for patients > 75 years.

Patients FAQs

How long will I be in hospital?

AAA repair

6-8 nights

 

Hernia repair – inguinal

1 night

Appendicectomy

1-2 nights

 

Hernia repair – umbilical

Same day

Apronectomy

2-3 nights

 

Hysterectomy – abdominal

3-4 days

Arthroscopy

same day

 

Hysterectomy – vaginal

2-3 days

Arthroscopy + repair

2-3 nights

 

Hysteroscopy

Same day

Bowel resection

5-8 days

 

Ileal conduit

6-8 days

Carotid endarterectomy

4-5 days

 

Laminectomy ± fusion

5-7 days

Cholecystectomy – laparoscopic

2 nights

 

Nephrectomy

8-10 days

Cholecystectomy – open

2-3 nights

 

Pacemaker insertion

1 night

Colonoscopy

Same day

 

Pilonidal sinus

1-2 night

Colonoscopy – enfeebled

1-2 nights

 

Plastic procedures

Same day

Coronary angiogram

1 night

 

Plastic procedures – major

3-4 days

Cystoscopy

Same day

 

Renal biopsy

1 night

D&C

Same day

 

Thyroidectomy

2-3 night

Femoral angiogram

Same day

 

Total hip replacement

4-8 days

Fem-pop bypass

4-5 nights

 

Total knee replacement

4-6 days

Gastroscopy

Same day

 

TURBT

1-2 night

Haemorrhoids

3 nights

 

TURP

2-4 night

Hernia repair – incisional

1-2 nights

 

Varicose veins

0-1 night

 

 

 

VATs

3-4 days

Five fears patients have about anaesthetics

1.  That the anaesthetic won’t put them to sleep.

2.  That they won’t wake up after their operation

3.  That they will wake up during their procedure.

4.  That they will be in pain after their operation

5.  That they will be nauseated or vomit after their operation.

  

What are the risks of general anaesthesia?

· 

·  Unexpected intraoperative death in ASA I or II patients is less than 1: 280 000. 

·  Overall anaesthetic deaths in all non-emergency patients including those of ASA III and IV is about 1: 70 000

Very common risks (>10%)

Include: sore throat (if intubated), nausea and vomiting, headache, thrombophlebitis.

Common risks (1 - 10%)

Include: chipped teeth, DVT, postoperative hypoxia leading to confusion, residual effects of muscle relaxant drugs causing a brief period of postoperative weakness.

Less common risks (<1%)

Include: aspiration with chest infection, awareness, and laryngospasm in Recovery room. 

Rare risks (<0.1%)

Include: anaphylaxis, extrapyramidal syndrome and other acute drug reactions, “halothane” hepatitis, malignant hyperpyrexia, peripheral nerve damage, spinal column damage at intubation, corneal abrasion, vitreous haemorrhage, retinal infarction, middle ear damage, air and other embolism, cerebral hypoxia, peripheral nerve injuries caused by compression, intramuscular injection; plexus praxis caused by stretching, pneumothorax, and others. 

 

What are the risks of spinal anaesthesia?

·  Permanent major nerve damage about 1:14 000.

·  Risk of cardiac arrest  ~ 6/10 000Risk of cardiac arrest 6R 

·  Degrees of motor paralysis <1:20 000.

·  Temporary minor nerve damage ie. areas of numbness <1:1000.

·  Post-dural puncture headache 15% with higher incidence if age <45 years.

·  Epidural and spinal anaesthetics problems include severe hypotension, local anaesthetic induced convulsions and total spinal anaesthesia. 

·  Much postop back pain is due to poor positioning on the operating table. 

What are the risks of epidural anaesthesia?

Outside younger fittter or obstetric patients, fewer epidurals are being used now.

·  Persisting

·  nerve damage higher than with spinal anaesthesia; about 1:12 000.

·  Post dural puncture headache requiring blood patch about 1:100.

·  Temporary posture related back pain — about 14:100.

·  Total spinal anaesthesia: <1:10 000.

·  Transient low back pain 16:100.

·  Broken catheters left in epidural space.

·  Epidural haematomas used to be 1:50 000, but since 2000 with the use of LMWH anticoagulants is now estimated to be 1:4000.

·  Infection and abscesses is about 1:1400.  If epidurals are used in immuno-compromised patients such as those with HIV/AIDS or for relief of cancer pain then the incidence is as high as 1:800.

About back pain after epidurals and spinals

·  Back pain is a major complaint following spinal and epidural anaesthesia.  Fortnately mostly it is benign.

·  Assess back pain carefully after epidural anaesthesia because it may reveal either epidural abscess or haematoma.  Backpain with either fever or nerological signs = immediate MRI and neurological referral.

·  Patients frequently blame 'the needle' for ‘damaging their spine’. This is unlikely.  The lumbar spine’s natural lordotic is curve supported by ligaments, and muscles.  Under spinal and epidural anaesthesia the protective muscle tone sustaining the arch is lost.  While supine, the spine flattens out stretching the ligaments.  Not surprisingly patients wake with back pain.  To prevent pain support the lumbar arch with a folded towel.

·  After childbirth there are no statistically valid differences in incidence of long term low back pain, disability or movement restriction between woman who receive epidural pain relief, and women who receive other forms of pain relief.

What are the risks of brachial plexus block?

· 

·  Transient paraesthesia (lasting less than a month) about 1:125

·  Transient motor weakness (lasting less than a month)  about 1:700;

·  Permanent nerve damage approx 1:12 000.  

Relative risks

·  Risk of being killed by a bolt of lightning in Victoria {ABS]

·  Men               1:70 000

·  Women          1:100 000

·  Risk of being murdered in Australia in the next 12 months 1:50 000

·  Risk of being murdered in USA in next 12 months 1:12 600

·  Risk of being killed in a car accident in Australia in the next 12 months 1:10 000

·  Risk of catching HIV from a blood transfusion << 1:1 000 000

·  Probability of winningTattslotto with one line 1: 62 000 000

·  Probability of winningTattslotto with two lines 1: 59 999 999

How long to fast

Fast forward

Box Hill Policy is:

·  No fluids within 2 hour of surgery.

·  No food within 6 hours of anaesthetic.

·  Afternoon cases may have light breakfast at 7.00 am.


 

Ingested material

Minimum fast

Water

2 hours

Breast milk

4  hours

Infant formula

4 - 6 hours

Non-human milk

6 hours

Light meal

6 hours

 

Warn your patients of the consequences of not fasting.  Some still have a BigMac™ on the way to hospital, but reckon that's OK provided they don't tell anyone.

What about fluids?

· 

·  Low risk patients may drink water until the time they leave home to come to hospital. 

·  Water is water and does not include tea, coffee, fizz or water with their whisky.

·  No milk or milk products - they form gluggy strings of curds in the stomach - dreadful to vomit, worse to aspirate, and impossible to retrieve through a bronchoscope.

·  Stop breast milk four hours before surgery.

What about food?

·  Patients admitted at 10.30 hrs may have a light breakfast at 7.00 am for an operation starting no earlier than 13.00 hrs.  A light breakfast = tea, two slices of toast with jam or honey, fruit juice, but no milk. 

·  Fast from midnight if they are having morning surgery at 08.30 hr or later. 

· 

·  A patient only fasted for 4 hours after food still has food in their stomach.

·  If they have been injured after a shortly after a meal, the peas and carrots may remain in the stomach of 48 hours or more.

·  A six-hour fast after a light meal is optimal.

What medications to take on the day of surgery

· 

·  Take usual medication with a full glass of water before leaving home.

·  Omit diuretics because they may cause mild hypovolaemia.

·  Avoid gastric irritants eg. aspirin, NSAIDs and drugs taken with food.

·  Type 2 diabetics should omit their oral hypoglycaemic drugs .

,      Fast facts about aspiration

·  The topic of fasting causes some anaesthetists to become a touch emotional.  They mightily fear gastric aspiration syndrome. Major aspiration of stomach contents into the lungs during an anaesthetic is mercifully rare, usually disastrous and often fatal. 

·  On the other hand, prolonged water deprivation increases postoperative nausea and vomiting, delays discharge after day surgery, and increases the risk of lung damage if patients do aspirate.

·  Severe aspiration is said to occur in 3:10 000 GAs, but it is probably less than this.

·  Even the longest fast won't abolish aspiration because the stomach is never empty. 

·  Water clears exponentially from the stomach; after a drink of water half is gone within 12 minutes and 5 half times later (60 minutes) it has all gone.

·  If more than 1 hour has elapsed since their last drink of water, the patient’s own gastric secretions determine the content, pH and volume of their stomach. 

·  Chewing gum or sucking sweets while fasting fills the stomach with gastric juice. BAD!

·  Subtle aspiration perhaps in the recovery room soon after emergence from anaesthetic probably causes many postop chest infections.

·  Aspiration is particularly lethal in pregnant women = Mendlesson’s syndome. 

·  A fasted stomach has up to 20-30 ml of fluid in it containing hydrochloric acid with a pH of somewhat < 1; this is the blistering equivalent to car battery acid.

·  An urban myth persists about the volumes and pH of aspirate needed to cause problems. The evidence was based on an experiment on a single monkey 30 years ago. It can be summarized: aspirate is bad, particulate aspirate is worse, acid aspirate is terrible, and the bigger the aspirate the worse the outcome.

 

It’s is far better to have water in the stomach,

than concentrated hydrochloric acid

Who is at high risk of aspiration?

· 

·  Hiatus hernia, reflux or heartburn.

·  Obese, but especially with a BMI >35.

·  Gastroparesis, (diabetics, Parkinson's disease).

·  Disorders affecting oesophageal sphincter eg. scleroderma.

·  Are taking opioids including fentanyl patches (pyloric sphincter tone higher).

·  Are in acute pain.

·  Have difficult airways.

·  Are pregnant.

·  Can't cough effectively (eg. malnutrition myaesthenia, or neuromuscular disease).

How to reduce the risk of aspiration

·  Only patients at high risk of acid aspiration need prophylaxis to reduce the risk.

·  Use oral pantoprazole 30 mg the evening before and repeat 2 hours before surgery. 

·  Give 30 ml of 0.3 M sodium citrate in the induction room.

About awareness

·  Some people are more resistant to the effect of anaesthetic drugs than others are. 

·  Awareness follows a continuous spectrum from a brief sensation of hearing something, through to being wide awake, and conscious of their surroundings. 

Explicit awareness

·  About 0.2 - 0.9%  (roughly 1:3000) patients have some recall of events while under general anaesthetic.  This does not necessarily mean they are in pain.

·  The risk is highest (about 1:150) in general anaesthesia for Caesarean section; but is somewhat less for emergency surgery and those with heart failure. 

·  Most events occur during emergence or early recovery; they wake up still intubated, or have residual paralysis and are unable to move.  

·  Warn your patient if they fall into a risk group. 

Pseudo-awareness syndrome

·  Pseudo-awareness is a common problem. It may cause anxiety for years afterwards.

·  Do yourself and your patient a favour.  Tell them that just because they have an oxygen mask on w/hen they wake up in the Recovery room, it does not mean that they were awake during surgery.

Dental disease

Teeth

·  Damage to teeth is the

·  most common reason patients sue anaesthetists. 

·  Caps, bridges, crowns and other prosthetic work can come adrift either during intubation, or when patients get trismus and grind their teeth on emergence.  

·  Warn patients that the anaesthetist will be careful, but cannot guarantee no damage.

·  Use a standard notation to record the location of any prosthetic work or loose teeth.

 

Gingival disease

Where there is gross inflammation or pus needs to be fixed by a dentist before surgery especially before inserting foreign material (THR, mesh, or vascular grafts).

Body piercings

·  Body jewellery is a touchy subject. Applying strict rules can irritate everyone. 

·  Patients often can’t, or sometimes won't, remove their piercings.

·  Be pragmatic, but   warn your patient of possible mishaps.

·  If possible, tape over and pad the item before the patient goes to theatre.

·  Note in the medical record the site of the piercings and the state of adjacent tissue.

·  Make sure the items are still there after surgery.

Remove

·    Tongue and lip jewellery, because they can end up in a bronchus.  Organise this when they are booked for surgery, because sometimes it needs special gadgets to remove them.  It may be necessary to cancel surgery if jewellery is still there.

·  Items that may become caught or ripped out during surgery by ECG leads, drapes or diathermy cables.  It is not a good look to come back with half a nipple ripped off.

·  If there is risk of pressure damage eg. nipple jewellery when the patient is laid prone, or with lip studs if a facemask is used.

·  If the piecing is close to the planned surgical incision.

·  Nasal septum, nose or‑ ear jewellery before ENT operations.

·  If there is any inflammation or frank infection around the site of the piecing.

Don’t remove

·  If the surgical site is distant to genitalia piecing.

·  If a male has a penile ring and simply needs a catheter.

Headache

· 

· 

·  Following general anaesthesia the cause of headache is uncertain.

·  Caffeine withdrawal probably causes many of them.

·  Headache is aggravated by fluid restriction, fasting, and transient hypoxaemia. 

·  Usually it responds to hydration and paracetamol.

Things that worry patients

Things that worry patients about their anaesthetic, but they usually "forget" to ask:

·  Severe pain is largely avoidable — they must tell nurse if they are in pain.  For almost all surgery, there should be little or no pain while they are lying still, and it must never interfere with their sleep. They should expect some pain while moving about.  If you patient is having major or painful surgery notify the pain team ahead of time.

·  Where blood transfusion is unlikely, then reassure your patients that it is unlikely. They worry about HIV/AIDs and hepatitis.

·  Urinary catheters - young men especially worry about such things.

·  Tell them that when they wake up from their operation wearing an oxygen mask it does not mean they woke up during the anaesthetic, or that their life is in danger.  I hear frequently, "Oh Doc, I nearly died after my last operation — they had to give me oxygen".

·  Most patients will have an IV drip running; this does not mean that they are dying.

·  Encourage them to do their leg exercises as soon as they emerge. This helps protect patients against DVT, and gives them a feeling of contributing to their recovery.

·  Warn them they be nauseated – especially if they are in the higher risk groups.

·  [Pssst! – the word is nauseated, not nauseous. Nauseous describes something so indescribably vile, that it makes everyone feel sick eg. nauseous (soiled) bed linen}

How long will it take to get over my operation?

·  Ask the operating surgeon! 

·  Principal factors influence recovery from and surgery are: 

·  Physical health: Fit people recover more quickly than those with multiple medical problems.  

·  Age; the young heal and bounce back faster than the elderly; 

·  Emotional status; optimists do much better than pessimists; mentally dynamic people do better than the slower, and clinical depressed or demented people do worst of all. 

·  The stitches fully heal in 6 weeks.  Maximum strength may take months to years.

·  Scares turn white after about a year.

·  Major bones are near full strength in 4 – 6 months.

·  Most elderly people take a long time to regain their ‘get up and go’; sometimes this may be 3 - 9 months depending on the trauma of surgery, and the amount of postoperative cognitive disorder. 

·          Clinical depression is common after major or disfiguring operations and cancer surgery.  Urge your patient to seek help if they are not sleeping properly or they have lost their optimism.

Do anaesthetics affect my brain?

·  Yes, temporarily.  Anaesthesia is a reversible drug induced coma.

· 

· 

·  Most of its effects wear off in a few hours, but they may take longer.

·  Patients may not react as quickly as normal to any emergency for up to 48 hours (or more) after a long anaesthetic.

·  Where long acting diazepam or nitrazepam have been used in the elderly, these drugs affect their conditioned reflexes for as long in hours as their age in years. Therefore, an 80 year old man driving his car after a single dose of 10 mg of diazepam will not necessarily stop at a red traffic light for more than 3 days after this drug.

·  Midazolam tends to affect elderly men, more than elderly women and probably for at least 7 or more hours.

,      Fast facts

·  If someone's personality changes after an operation, then provided their brain is intact, (they haven’t had a stroke) or they are not going mad – then there are three diagnoses: depression, PTSD or postoperative cognitive disorder. 

·  Depression after major surgery (especially for cancer) is a serious problem.  Don’t simply prescribe SSRIs - get help from a psychiatrist. Post-traumatic stress disorder is a major psychiatric illness – seek proper help.?

· 

·  Cognitive function is about how well people solve problems, remember things, and anticipate events. 

·  Technically cognitive impairment is a blend of aphasia (language disturbance), apraxia (impaired ability to carry out motor activities despite intact motor function), agnosia (failure to recognise or identify objects despite intact sensory ability), and disturbance in the ability to plan, organise, sequence, and abstract.

·  Postoperative cognitive disorder (POCD) is a very real problem affecting surgical patients over the age of 60 years (particularly men), 25% of whom will have subtle impairment of their cognitive function 7 days after surgery, and 14% will still be impaired at 3 months and 10% at 2 years.

·  Little is known about POCD - or its prevention.  It is worse with longer anaesthetics. 

·  There is evidence that periods of hyperventilation during anaesthesia may contribute.

When can I start driving again?

· 

·  Ask the surgeon, and warn your patient. 

·  But from the anaesthetist’s point of view patients should not drive or use machinery following:

·  General anaesthesia — for at least 24 hours.

·  Brief procedures (eg. gastroscopy) — until after a normal night’s sleep.

·  Local anaesthesia without sedation eg. dental blocks —about 2 hours.

·  If they do drive when impaired there is a high risk of accidents. The police have no sympathy and they will prosecute.

Other things to warn of

·  Warn patients to avoid using dangerous machinery that may injure them such as chainsaws, lawnmowers, or any electrical or mechanical tools.   Skydiving is out too.

·  Similarly, they should avoid making financial or legal decisions, because they may not be able to think clearly.  Warn them not cook, because of the risk of tipping hot fluids over themselves or others.


Exercise and MET Score

A graded response to exercise is the single best test of cardiopulmonary fitness. The MET score is that level of exercise maintained (not attained) before patients are stopped by breathlessness. Many patients’ estimation of their exercise capacity is a poignant memory of their youth or macho bravado.  Older women do not seem to exercise at all, while older men “used to play league football”. It is not helpful to grade exercise endurance as good, OK or poor, so we have developed the following modified MET score.  

 

One MET = oxygen consumption of 3.5 ml/Kg/min

One KCal = 200 ml oxygen consumed

 

One MET is equivalent to walking at a rate of one kilometre per hour (which is of course different from walking one kilometre in one hour), while two METs is 2 km/hour and so on.

 

1   MET

Eating, getting dressed, walking from room to room, working at a desk, getting up to change the TV channel.

2   METs

Taking a shower, cooking.  Playing bowls.  Walking down 8 steps.  Making the bed.  Hanging out the laundry.  Walking around shopping mall.

3   METs

Vacuuming, sweeping floors, or carrying groceries from the car. Walking 1.5 km on level ground in half an hour (ie around the average suburban block). Pushing a full shopping trolley around supermarket.  Walking up two flights of stairs (one floor), but puffed at the top.

4   METs

Raking leaves, weeding. Pushing a full shopping trolley from the supermarket to the car. Walking 4 km in one hour.  Walking up two flights (one floor) of stairs without being puffed at the top.

5   METs

Walking briskly (5 km in one hour).  Climbing four flights of stairs without puffing at the top.  Using a power mower.  Fast ballroom or square dancing.

6   METs

Cycling moderately.  Walking up moderate hill. Heavy carpentry, mowing lawn with a push mower. Walking 6 kilometres in one hour.

7   METs

Carrying a 6-year-old child, perform heavy out door work (digging soil, chopping wood).  Walking 7 kilometres in one hour. 

8   METs

Carrying a 6-year-old child up one flight of stairs, move heavy furniture, jog slowly on a flat surface, climb stairs quickly.

9   METs

Bicycling at a 20 Km/hr pace, sawing wood, jumping a rope slowly.

10  METs

Brisk swimming, cycling up a hill, jog at 10 Km per hour.

11  METs

Carrying a heavy load (ie. Child or firewood) up 4 flights of stairs.  Bicycling briskly and continuously, backpacking.

12 METs

Running briskly and continuously on level ground at 12 km per hour

 

Remember: 4 MET = one floor (2 flights of stairs).

 

For major surgery the score should be at least 3 - 4 METs of sustainable exercise.

For minor surgery the score should be at least 2 - 3 METs of sustainable exercise.

Being unfit can be lethal

A patient with a MET score of 5 has enough cardiopulmonary reserve to cruise through most surgery. An anaerobic threshold < 13.5 ml/Kg/min (equivalent to sustainable exercise capacity of  less than 4 METS) doubles intrahospital mortality for major surgery, and increases the risk of death for at least 6 months after operation and probably longer.

 

The single best predictor of perioperative adverse cardiac events

is the patient’s ability to sustain exercise.

Do you need just one parameter to gauge your health?  Then it is your MET score. For every 1 MET increase in your fitness, mortality decreases by 12%. And that’s for all causes of mortality – cancer, strokes, hip fractures – everything and not just cardiovascular disease.

How to use a pulse oximeter to test cardio-respiratory function

Use

a portable pulse oximeter to unmask problems.  Attach the oximeter to the patient and then get them talk to you as you walk 100 metres down the corridor and back (or better still climb 2 - 3 flights of stairs).  A decrease in oxygen saturation of >5% suggests an inability to maintain tissue perfusion; in contrast a normal person does not desaturate.

ECOG performance status

Use this scale to stratify the severity of the patient's incapacity, and plan management.

*The Eastern Cooperative Oncology Group.

Grade

ECOG performance status

0

Fully active, able to carry on all pre-disease performance without restriction.

1

Restricted in physically strenuous activity, but ambulatory and able to carry out work of a light or sedentary nature eg.  light house work, office work.

2

Ambulatory and capable of all self-care, but unable to carry out any work activities.  Up and about more than 50% of waking hours.

3

Capable of only limited self-care, confined to bed or chair more than 50% of waking hours.

4

Completely disabled.  Cannot carry on any self-care.  Totally confined to bed or chair.

5

Dead

`      Physiological foundations

The heart and lungs work as a single cardio-pulmonary unit to supply oxygen to the tissues.  Oxygen is passed sequentially from lungs to haemoglobin to tissues and their mitochondria.  Any weakness or bottleneck in this chain of events disrupts tissue oxygen supply. Unless enough oxygen gets to the mitochondria in the cells at a high enough pressure then oxidative metabolism collapses and the patient starts to die.

 

There are four components to the oxygen transport chain:

  1. Good lung function – to get the oxygen in and carbon dioxide out.
  2. Adequate cardiac output to pump the oxygen to the tissues.
  3. Enough haemoglobin to carry it there -
  4. Metabolic conditions have to be just right. eg. pH, temperature, and ion balance. 

 

Failure of any one of these components predisposes to tissue hypoxia. From this you can readily see that sick lungs, cardiac failure, anaemia, and metabolic disturbance will combine to amplify tissue hypoxia.  Most patients will tolerate one perturbation eg. cardiac failure or sick lungs; but two or more diseases combine to cause disaster.  So beware of the patient with cardiac failure and anaemia, who subsequently gets pneumonia and runs a fever – such a patient is in deep deep trouble, and may well die.

Clotters

Our species would not have survived long if blood did not clot in the right place at the right time. Evolution is not the rule; it is the exception. Genetic selection has tinkered with the clotting process over millions of years, and in doing so has heaped complexity on complexity - hence the intricacy of the clotting cascade. 

We are primed to clot when we are injured, or after giving birth (or having a miscarriage).  The bad news is that the body interprets tissue damage during surgery as an injury.  Additionally, severe emotional stress (the anticipation of injury) increases blood coagulability. 

Pulmonary embolism remains a major cause of post surgical death. In fact, more Australians die from PE than women die of breast cancer. PE is largely preventable. 

Problems occur where blood clots inappropriately, either at the wrong time (on plane trips), or in the wrong place (venous thrombosis or DIC). There is a dauntingly long list of inherited and acquired causes of clotting. .

About 4% of the population have inherited Factor V (Leiden) mutation. This makes them superclotters – definitely an advantage for stone-age hunters, but not in the wilds of South Yarra.  Pregnant women also temporarily become superclotters.

Why patients take prophylactic anticoagulants

Previously the patient has had a DVT or PE or an embolic stroke, or is at risk of these problems.

Those with a cardiac stent pose particular problems.  If you take them off their anticoagulant to perform surgery, they are very likely to clot off their stent and have an AMI.                                                                       More about stents          +          50

Hypercoagulability testing in superclotters

Don’t routinely test for inherited conditions if there is no a family history of clotting. However, if your patient has had spontaneous or recurrent VTE and has never been investigated then you need to check they are not supper clotters.

 

Family history - inherited

No family history – spontaneous

Activated protein C resistance

Activated protein C resistance

Prothrombin mutation

Prothrombin mutation

Antiphospholipid antibodies

Antiphospholipid antibodies

Plasma homocysteine

Plasma homocysteine

Factor VIIIc

 

Antithrombin III

 

Protein C

 

Protein S

 

If the patient is taking warfarin then Protein C or Protein S measurements are unreliable.

Thromboprophylaxis

Consult the Eastern Health Protocol for Thromboprophylaxis available on the Intranet.

PE        = pulmonary embolism – a sneaky disease

DVT      = deep vein thrombosis  - can occur in axillary vessels too.

VTE      = DVT ± PE

(       Fast forward

Three factors contribute to DVT/PE:

·  Venous stasis,

·  Prothrombotic states,

·  Abnormalities in the endothelium or vessel wall.

 

If your patient has ever had a DVT or PE, the risk of postoperative VTE is either high or extreme.

,      Fast facts

·  DVT is common

·  PE can be elusive to diagnose, and it is a major killer.

·  VTE is largely preventable.

·  Deep vein thrombosis is a major complication of orthopaedic surgery, cancer and other chronic illnesses.

·  Even with prophylaxis about 1% of hip replacements die from PE, but without it the mortality rate is 4 – 7%.

·  If you don’t die from the PE, then your DVT can cause a miserable post-thrombotic syndrome with chronic leg swelling, varicose veins, pain, and skin ulceration.

·  Prevention includes: low molecular weight heparins (LMWH), unfractionated heparins (UH), compression stockings, and intermittent calf compression. 

·  Heparins reduce DVT by 50 – 70%.  Aspirin is far less effective.

· Compression stockings + LMWH more effective than LMWH alone.

Prothrombotic states

Virchow’s triad:  if you find a medical condition or encounter a situation that (1) disturbs or slows blood flow, (2) causes inflammation, or (3) primes the blood to clot, then DVT and PE are likely.  If the patient formed a DVT in the past, then they are highly likely to do it again.   The more factors present, and the more severe they are, the more likely they are to form a clot.

Conditions predisposing to VTE.

Slows blood flow

Immobility, obesity, heart failure, age >60 

Disturbs blood flow

Turbulence: stents, varicose veins, AF, sitting in aircraft, pelvic pathology, heart valves.  

Inflammation

Cancer, lung infections, connective tissue disorders (rheumatoid arthritis, SLE, etc), inflammatory bowel disease.

Primes the blood to clot

Pregnancy, HRT, OCP, tissue damage, surgery, prothrombotic diseases.

Hypoxia, pain, sepsis, or anything else raising noradrenaline levels. 

Done it before

Previous DVT/PE, recent stroke, recent MI.

What to do about anticoagulants

Anticoagulants include: warfarin, clopidogrel, dipyridamole, and aspirin.

Other drugs affecting clotting include: NSAIDS, SSRIs, GTN. 

Aspirin

·  Low dose aspirin (100 – 150 mg) is a moderately effective anticoagulant.

·  Aspirin disables platelets for the whole of their 10-day life span.

·  For most, but not all, surgery adequate coagulation (meaning 60% platelets are functioning) is re-established 4 days after ceasing aspirin.

·  Studies show that low dose (60–100mg) aspirin a day has only a trivial effect on surgical bleeding 24 hours after the last dose. Nevertheless, many surgeons dispute this.

·  Avoid prescribing aspirin with warfarin because of the unacceptable risk of GI bleeding.

·  Aspirin is often added to other anticoagulant regimes if there are worries about the risk of clotting; for instance recent coronary artery stents, or embolic stroke. In this case add esomeprazole to prevent gastric beeds. 

Stop aspirin

·  2  weeks before neurosurgery, inner ear surgery, and open eye surgery.

·  7  days before urological surgery

·  4  days before other surgery including colonoscopy or gastroscopy

Do NOT STOP aspirin if

·  excision of skin lesions by plastic surgeons;

·  history of TIAs, coronary stents, angina or retinal vein thrombosis in past 6 months;

·  known carotid or vertbrobasilar disease’

·  vascular surgery.

Clopidogrel

(Iscover®, Plavix®)

· 

·  Clopidogrel permanently disables platelets for all their 10 day life span.

·  Causes all sorts of problems if not taken off 7 – 10 before most surgery. 

·  Plasma half-life = 18 hours.  It takes 5 half lives (4 days) to clear from the circulation. 

·  It may be used with aspirin in high-risk cases, but this increases the risk of GI bleeding.

Stop clopidogrel

·  21 days before intracranial, spinal cord, or inner ear surgery.

·  10 days before urological surgery .

·  7 days before other surgery

Don’t stop clopidogrel

·  Some vascular surgeons prefer their patients remain anticoagulated, particularly for carotid endarterectomy, however check with surgeon first;

·  TIA or PTCA in past six months;

·  Retinal vein thrombosis at any time.

·  Where it would be hazardous to continue clopidogrel, discuss alternative anticoagulation with the surgeon.  This may involve substituting subcutaneous dalteparin in the days preceding the surgery.

Clopidogrel and aspirin

Patients may infarct, and some die if their coronary stent clots off then.  Cardiologists combine clopidogrel and aspirin to prevent post stent thrombosis for 3–6 months after bare-metal stent (BMS), and at least a year after drug-eluting stents (DES).  The downside of this regime is that the addition of aspirin increases the risk GI bleeding by seven fold when compared with clodigrel alone.

Dipyridamole ± aspirin (Asasantin)

·  Manage as for clopidogrel.

·  Dipyridamole is about as effective aspirin, but expensive. 

·  Dipyridamole reduces platelet aggregation by inhibiting their uptake of adenosine.  Since it is used in cardiac stress testing as vasodilator to provoke myocardial ischaemia, it would be unwise to use it in patients with IHD.

·  It is uncertain if the dipyridamole + aspirin may preventi strokes or TIAs. 

·

NSAIDs and COX-2 inhibitors                                     +         21

·  Stop 4

·  4 days before surgery.  Substitute paracetamol for pain control,

·  the only virtues of the COX-2 inhibitors celecoxib (Celebrex®) and meloxicam, is that they cause less gastritis.  They have the same renal problems as other NSAIDs, and both aggravate bleeding.

SSRIs

·  SSRIs have about the same anticoagulant effect as low dose aspirin.

·  Do not stop SSRIs or psychiatric medication without discussing it with the patient’s psychiatrist because there is a substantial risk of suicide.

Warfarin

Warfarin  (Coumadin®) is prescribed for 3 months (and no more) following DVT or PE, and for a lifetime in super clotters with inherited prothrombotic states, and those with chronic atrial fibrillation, or with mechanical valve prostheses.  In patients with AF, warfarin (keeping INR at 2.5) reduces the annual risk of a first ischaemic stroke from 7% per year to <3%. It is a potentially hazardous drug causing major bleeding in 1-2% of people treated  (intracranial bleeds in 0.1%) with each year of therapy. For every 0.5 increase in INR the risk of bleeding compounds by a multiple of 1.43. Different brands of warfarin are not bioequivalent. You can’t swap brands midtherapy.

Don’t stop warfarin

·  Don’t stop warfarin for superficial plastic surgery where bleeding can be controlled by simply pressing on the wound.

·  Don’t stop warfarin for simple dental procedures and peridontal work. (Stop warfarin for extractions).

 

b     Little gem

            Patients on warfarin take 3 +INR days for their INR to return to <1.5. 

How to stop warfarin

·  Stop warfarin 5 clear days

·  5 c5 before surgery. This means that if surgery is on a Thursday, then last dose of warfarin is at 4.00 pm the previous Wednesday.

·  Write down the date for the patient to take their last dose. Don’t simply tell them to stop 5 days preop because many patients can’t count.  Stick a red sticker on their warfarin to remind not to take it. “Like a traffic light”.

·  They need INR measured on their visit to Preadmission clinic and again on the day before admission.

What is the target INR?

·  Some vascular surgery can be performed on patients with INRs up to 2.  Check with the surgeon about their requirements

·  For most surgery an INR <1.5 is adequate, but many surgeons prefer it less than this.

·  Epidural and spinal anaesthesia requires an INR <1.2.

·  Urological surgery, such as TURPS, nephrolithotomy etc, requires an INR <1.2

·  For intracranial, intraspinal, middle-ear, or eye surgery the INR must be normal

When to order LMWH cover

Patients at extreme risk VTE or embolic events need LMWH cover in the week before surgery. Low molecular weight heparins (LMWH) include dalteparin, and enoxaparin.

Who needs preoperative interval LMWH cover?

Those taking anticoagulants and who are at high or extreme risk of clots:  

·  DVT or PE or embolic stroke in last 3 months;

·  Coronary stents while the patient is taking clopidogrel;

·  Super clotters with prothrombotic disease who have a VTE at any time in the past;

·  Mitral valve or aortic valve replacements with mechanical device;

·  Valvular heart disease with ischaemic stroke in past.

Who does not need LMWH cover?

LMWH cover is NOT needed for patients who are already on anticoagulants with:

·  Chronic AF with no history of embolic episodes

·  Valvular heart disease unless an embolic stroke in past

·  DVT or PE > 3 months ago

·  Embolic stroke or AMI > 3 months ago.

Who should I admit and stabilize on intravenous heparin?

No one.  This technique is unnecessary, and hazardous. There is a substantial risk of inducing HITs (heparin induced thrombocytopenia), and a small but definite risk of haemorrhagic stroke when substitution LMWH for warfarin.


 

 

Extreme risk

High risk

Medium risk

 

Previous PE or DVT

               and

DVT ± PE in < 3 months

Protein C deficiency

Protein S deficiency

Antithrombin III deficiency

Factor V (Leiden) mutation

Prothrombin 20201 mutation

Protein C deficiency

Protein C deficiency

Anti thrombin III

Factor V (Leiden)

Prothrombin 2020

All mechanical valves

Embolic stroke < 3 months

Retinal vein thrombosis

Previous stroke + valve

Porcine valve > 3 months

Lone  AF

AF +  CCF

VTE  > 3 months

Tachy-brady syndrome

 

Asymptomatic valvular disease.

Days

Extreme risk

High risk

Medium risk

-6

Last dose of warfarin

Last dose of warfarin

Last dose of warfarin

-5

Nil

Nil

Nil

-4

Start LMWH once INR <1.6

Start LMWH once INR <1.6

Nil

-4

Daltaparin 5000 units s/c

Daltaparin 2500 units s/c

Nil

-3

Daltaparin 5000 units s/c

Daltaparin 2500 units s/c

Nil

-2

Daltaparin 5000 units s/c

Daltaparin 2500 units s/c

Nil

-1*

Daltaparin 5000 units s/c

Daltaparin 2500 units s/c

Nil

Surgery

Heparin 5000 units s/c

Heparin 5000 units s/c

Heparin 5000 units s/c

+1

Start warfarin at maintenance dose as soon as possible

* Measure INR the day before surgery on all patients who take warfarin.

How to do order LMWH interval cover

·  Arrange LMWH cover through Hospital-in-the-Home or their local doctor.

·  For most purposes prescribe dalteparin 2500 units s/c daily is sufficient. 

·  For those with prothrombotic states who have had a previous DVT/PE then prescribe dalteparin 5000 units s/c.

·  In patients with LBM < 50 Kg use half the dose of anticoagulant.

·  In patients >110 Kg use the patient’s lean body mass to calculate dose of LMWH.

·  In patients with CKD who have a eGFR < 30 ml/min/m2 or creatinine > 180µmol/L use a normal loading dose, and then halve the maintenance dose.

·  Patients receiving full anticoagulant doses of warfarin or one of the heparins do not require additional thromboprophylaxis.

·  Those having superficial plastic surgery usually can stay on their anticoagulants.  But check with the surgeon first.

How to monitor LMWH

·  No need to monitor LMWH levels unless patient has chronic kidney disease (creatinine > 0.18 mmol/L or eGFR <30 ml/min/1.73 m2).

·  Use anti-Xa levels if you need to monitoring the level of anticoagulation.

·  Check anti-Xa levels 4 hours after the last dose of LMWH was given.

·  For once daily injections the optimal range of anti-Xa is 0.9 – 1.8 units/ml.

·  For twice daily injections the optimal range of anti-Xa is 0.6 – 1 units/ml.

How to reverse LMWH in a hurry

Use protamine

·  If < 8 hours since last dose of LMWH use:

·  If  8 – 12 hours since last dose of LMWH then use a half dose of protamine.

·  If > 12 hours since last dose of LMWH then probably no need to reverse LMWH. Give protamine IV slowly over at least 15 minutes because it elevates pulmonary artery pressures and may cause wheezing.  

How to reverse warfarin to achieve a normal INR

Normal INR = 1. INR for most surgery INR needs to be <1.4.  Sometimes it is necessary to reverse warfarin either urgently or in the next 12 hours.

INR

Non-urgent

Urgent

2–4

Withold warfarin night before surgery.

Give oral vitamin K at least 12 hours before anaesthetic,

Check INR 1 hour before surgery.

Restart warfarin, as soon as possible, preferably on day of procedure at previous maintenance dose

Give vitamin K

Then add Prothrominex (better)

or FFP (just OK).

>4

Do the above + consult a haematologist.

 

Remember some low risk procedures do not need warfarin to be stopped. These include anything where where you can press on the wound to stop bleeding, and simple dental procedures (but not tooth extraction). 

How to reverse warfarin in a hurry

How to use Vitamin K1 to reverse warfarin

·  Even high dose Vitamin K1 takes 24 hours to fully reverse the effects of warfarin 

·  Oral vitamin K1 works better than IV.  Give 2 mg orally at least 12 hours before surgery.   If INR >4 then use 5 mg.

·  If you can’t get oral vitamin K you may have to give an oral dose of the intravenous form (Konakion®), even though it is not officially approved for use this way.

·  Don’t use intramuscular Vitamin K, because its micellular formulation acts as a depot source making it difficult to re-stabilise warfarin therapy after surgery.

·  IV Konakion® can cause anaphylaxis in which case the mortality rate is ~ 20%.

How to use prothrombin complex concentrate (PCC)

·  If you can get it Prothrombinex-HT®, works in minutes.

·  Prothrombinex-HT® contains mainly coagulation factors II, IX and X.

·  Because Prothrombinex-HT® contains trivial amounts of factor VII you need to use FFP as an adjuvant.

·  You don't need to worry about ABO grouping when using Prothrombinex-HT®.

How to use Prothrombinex-HT

·  If, when the patient is admitted, their INR >1.5 then it is better to defer surgery and wait until the INR falls to within an acceptable range.

·  But, if your really have to proceed then give Prothrombinex® (25-50 IU/Kg lean body weight) plus 150 - 300 ml of fresh frozen plasma (FFP).

·  Prothrombinex-HT® does carry the risk of causing venous thrombosis, myocardial infarction, and disseminated intravascular coagulopathy.

What do I use if I can’t get Prothrombinex®

·  Use fresh frozen plasma 15 ml/Kg lean body mass.

·  FFP is available in all ABO blood groups. If you can't get the appropriate group, then use AB group FFP.

How many units of FFP do I need?

Patient weight

INR = 2

INR = 3

INR = 4

INR = 5

30 - 45 Kg

2

3

4

5

45 - 75 Kg

3

4

5

6

75 - 100 Kg

4

5

6

7

LMWH and epidural or spinal anaesthesia

·  Allow 6 hours to elapse after skin closure in a patient with an epidural before giving the first dose of LMWH.

·  For the first dose of LMWH use half the dose (Dalteparin 2500 units). Wait 24 hours before starting the full dose regime of LMWH.

·  If the patient has already received a preoperative dose of LMWH then delay the insertion of an epidural or spinal needle for 12 hours.

·  Remove epidural catheters no sooner than 2 hours before the next dose of anticoagulant is due.

·  If the patient has an epidural catheter and is receiving LMWH then avoid NSAIDs. 

·  Don’t use epidural catheters in patients with bleeding disorders.

Postoperative anticoagulation

Extreme risk

Recommendation

Major surgery with additional risk factors

·  Past history of VTE

·  Currently active cancer

 

Fondaparinux (Arixtra®)  2.5 mg s/c commencing 6 hours after skin closure and the once daily for 7 days. If extended prophylaxis necessary use dalteparin 5000 units s/c daily.

Fondaparinux needs prior approval from haematology registrar or consultant.

High Risk

 

Major surgery age > 60 years

 

Major surgery age < 60 years with one or more of the following risk factors:

·  All joint replacement surgery

·  All major orthopaedic surgery

·  All multiple trauma patients

·  Hip, pelvis or leg fractures

·  Thrombophilia

·  Major cancer surgery

·  Major soft tissue inury (crush, gunshot)

·  Caesarean section

 

 

Dalteparin (Fragmin®) 5000 units s/c starting 6 hours after skin closure then once daily.

 
                           And
 
Graduated compression stockings.
Consider intermittent pneumatic comprssion during surgery.
Moderate risk

 

Major surgery in patients < 60 years with no risk factors

Heparin 5000 units s/c starting 6 hours after skin closure and then twice daily.

Low risk

 

Minor surgery with minimal immobility and no risk factors eg.

·  Diagnostic laparoscopy

·  Cystoscopy, TURBT and TURP

·  D&C

Early mobilization

 

Warfarin tablets are a good alternative to daily dalteparin injections in patients who are likely to be immobilized for a long time (eg. 2- 3 months for an unstable fractured pelvis)

When to restart warfarin postoperatively

·  Ask the surgeon.

·  It is usually OK to start warfarin 6 hours after surgery unless there is bleeding, infection or the patient is nil orally, or there is an epidural catheter in place.

·  It takes 2 - 3 days for warfarin to build up to therapeutic levels.

·  To cover this 2 - 3 day period use unfractionated heparin (UH)  (but not dalteparin).

·  Heparin has a fast onset and fast offset , and can be reversed with protamine

Graduated compression stockings (GCS)

·  Graduate compression stockings reduce VTE.

·  Eastern Health recommends the brand Thrombexin ®GCS.

·  Follow the makers guide on how to fit them or they won’t work properly

·  Patients should put them on before surgery starts.

·  They need to be worn continuously the whole time patients are immobile.

·  Patients find GCS uncomfortable and tend to roll them down rendering them useless.

Contraindications to prophylaxis

Contraindications to chemoprophylaxis

·  Active bleeding

·  High risk of bleeding eg. haemophilia, thrombocytopenia, or active peptic ulcer.

·  Heparin induced thrombocytopenia or heparin allergy.

·  Already on chemotherapy.

Contraindications to mechanical prophylaxis

·  Mechanical prophylaxis inciudes graduated compression stockings and devices that provide intermittent calf compression.

·  Symptomatic peripheral vascular disease ie.claudication or absent pedal pulses.

·  Peripheral neuropathy with sesory or motor symptoms.

·  More than 1 cm of pedal or lower limb oedema.

·  Within 6 weeks of skin grafts

·  Active dermatitis or open wounds on the lower limbs.

 

Bleeding ?

Always consider causes  other than anticoagulants.

Bleeders

Bleeders

There are three groups of bleeders: vascular, platelet, and coagulation disorders.

·  Vascular and platelet disorders cause immediate prolonged bleeding from cuts, tooth extractions, and they have lots of bruises. 

·  Coagulation disorders (eg haemophilia) may not bleed straight after injury, but they bleed later into joints, muscles and the body’s hollow places– gut and urinary tract. 

 

(      Fast forward

What do I check with haemostatic disorders?

·  Don’t order skin bleeding times. They are wildly inconsistent for clotting disorders.

·  The best test for haemostatic disorders is to ask if they bleed or bruise easily.  If they don’t, then routine coagulation profiles are pointless. aPPT has a 15% false positive rate.  For medico-legal reasons all positives (including the 1:8 who are false positives) must be followed up.

·  If your patients has a known coagulopathy then consult a haematologist.

·  Found an incidental thrombocytopaenia?   Then take another sample for confirmation. 

b         Little gem

Look for petechia on the arm where the blood pressure cuff was placed.

Big bruises from little knocks?

·  Thrombocytopenia

·  Aspirin

·  Warfarin and other anticoagulants

·  Steroid therapy

·  Very elderly patients with thin skin

·  Scurvy (more common than you might think)

·  Bleeding disorders

·  von Willebrands disease  - may not have been diagnosed yet

·  Haemophilias – obvious and well known to the patient

Born Bleeders

Haemophilia

Diagnosis is not a problem. People with haemophilia know they have it.                

·  Haemophilia A =  Factor VIII deficiency

·  Haemophilia B =  Factor IX deficiency (also known as Christmas disease)

·  Haemophilia C =  Factor XI deficiency

von Willebrands disease

Patients often don’t know they have it.  M = F. Family history of bleeding. Mild cases often undetected. Routine screening tests (INR + aPTT) miss it. Lack vWFactor in endothelium.  Hormonal changes during pregnancy, and stress during surgery stimulate endothelium to produce wVF so they may have had uneventful surgery or deliveries in the past. Despire this they still need cryoprecipite before surgery. Consult a haemotologist. 

Bred bleeders

Thrombocytopenia

Zilions of causes, and ITP is a common reason for splenectomy.  But also think marrow failure: toxins, especially drugs; and occasionally we discover an undiagnosed lymphoma. 

Transfuse if platelet count:

·  <10 x 109/L with no risk factors;

·  <20 x 109/L with risk factors eg.  fever, antibiotics, recent surgery.

·  <50 x 109/L with risk most surgery and invasive procedures eg.  central vascular access, colonic biopsy, transbronchial biopsy.

·  Bone marrow biopsy does not usually require platelet cover, just press on the wound.

·  For neurosurgery surgery involving the spinal cord, or eye and ear surgery, platelet count should exceed 100 000/µL .

·  No epidural if count <100 000 x 109/L, or spinal anaesthetics if count <60 x 109/L

Minimum requirements for elective surgery

·  A platelet count of 60 000 /ml is more than adequate for most surgery although surgeons naturally enough prefer it to be >100 000.

·  Most anaesthetists prefer >100 000 for or spinal epidural anaesthesia

·  Surgery in closed spaces: neuro, spinal, eye, ear needs platelet count > 150 000 /ml

·  INR <1.5

·  aPTT <40 seconds

·  but, discuss with anaesthetists before deferring surgery.

 

b     Little gem

             Troublesome bleeders get big bruises from little knocks.

 

Normal platelet count is 150 000 – 300 000/ml. Platelets are disabled by aspirin, clopidogrel, NSAIDs, SSRI, and dipyridamole but the platelet count won’t be affected. They just don’t work. This is sometimes called thrombaesthenia.

 

 

 

Blood transfusions

Don’t get tangled in red tape

· 

·  The hopital’s blood bank will keep blood to group and crossmatch for up to 4 weeks.

·  If you don’t fill out their forms properly the blood bank won't process the blood. 

·  Specify the planned operation, the date of surgery, and how many units you need.

·  The law requires: “sufficient details in the medical record to allow a future clinical review to establish why blood product was given, and what the outcome was”.

·  When a patient has ”antibodies” the lab needs 24 hours to do the tests. The patient must re-attend to give another blood sample the DAY BEFORE surgery.

·  Grouping takes about 15 minutes.

·  A full cross-match by hand takes about 45 – 50 minutes but if there are unsual antibodies in the patient's blood, or the patient is taking methyldopa antibodies it may take 4 hours or more.

The top 10 patients likely to need a blood transfusion

1.  Anaemia with preoperative haemoglobin/haematocrit at or below the normal range.

2.  Low body weight <55 Kg.

3.  Small body size.

4.  Female sex.

5.  Age >65 years.

6.  Availability of preoperative autologous blood donation (PABD).

7.  Estimated surgical blood loss.

8.  Type of surgery – especially vascular surgery or where there is major tissue damage.

9.  Revision surgery needs more blood than primary surgery eg. revision THR

10. Intercurrent ischaemic heart disease or respiratory disease.

What are the signs of anaemia?

Hb Conc

Symptoms

90 – 80 gm/L

slight tachycardia, slight pallor, mild decrease in exercise tolerance;

70 – 80 gm/L

Pale, dyspnoeic on walking up flight of stairs

60 – 70 gm/L

severe dyspnoea on exertion, feels weak and exhausted

30 – 60 gm/L

White, dyspnoeic at rest, exhausted by walking a few metres;

12 – 20 gm/L

cardiac failure  

What are the common causes of anaemia?

Iron deficiency anaemia usually from chronic bleeding usually from bowel or menorrhagia. Other causes include anaemia of chronic disease, thalassaemia, and pernicious anaemia. 

About pre-donated autologous blood (PDAB)

·  Don't offer PDAB to a patient unless they specifically request it.

· 

·  PDAB is expensive ($600 per unit), not risk free, awkward to donate, has few advantages (now that leucocyte depleted blood is available) and not worth the effort.

·  You must be able to guarantee the date of surgery to avoid wasting the blood.

·  Don’t order more than two units, because fresh allogeneic (homologous) blood is better than autologous blood suffering from storage lesion. 

How to do it

·  Autologous blood donations are only collected at the central Australian Red Cross Blood Bank in the city or major regional centres.  Within two days of coming to Preadmission clinic the patient should make an appointment with Blood Bank’s Autologous Blood Coordinator (phone 9694 0359) to collect and store their blood.  Fill out the form available from Preadmission Nurse's office, and give the patient both the slip and the Red Cross’s information pamphlet.

·  The law says you must tell your patient that autologous blood is routinely tested for Hepatitis and HIV.  Autologous blood must be cross-matched before the patient gets their own blood back, so fill out a ‘Request for Blood Products’ form and staple it inside the front cover of their medical record.  Note on the request slip the date of surgery and that it is autologous blood. 

Who cannot pre-donate their own blood?

·  Anaemia with Hb <110 gm/L,

·  Treated or untreated cardiac failure,

·  Any infection,

·  Cerebrovascular disease or stroke,

·  Epilepsy,

·  Renal impairment or disease,

·  Pregnancy,

·  ASA grade II +

·  IHD now or in the past,

 

·  On medication for hypertension,

·  Previous hepatitis,

·  ß-blockers,

·  >75 years; or frail or unfit,

·  <18 years – need consent

·  Warfarin

·  Vascular end-organ disease,

·  Weight <40 Kg,

·  Steroids.

About guided donations

The Red Cross does not accept guided donations from a patient’s relatives or friends. They have proven to be less safe than blood obtained from screened regular donors. 

Special blood preparations

Pre-treated boutique red cells and platelets are available for very special occasions.

Red calls

·  Autologous: Special conditions apply to patients who need (or request) their own blood. The Red Cross Transfusion criteria are very strict.  Autologous blood is also used if patients have an antibody to a high incidence antigen.

·  Buffy coat poor: To reduce risk of febrile non-haemolytic blood reactions (FNHTR).

·  CMV antibody negative: For haematology and oncology patients who are CMV antibody negative, all neonates, all pregnant women (or use leucodepleted blood). 

·  Directed donations: There are extremely limited indications in special cases. Usually reserved for patents donating blood to children. Consult haematologist,

·  Irradiated: To prevent transfusion associated graft versus host disease in immunosuppressed oncology and haemotolgy patients.

·  Leucocyte depleted:  To further reduce risk of FNHTR and allo-immunization in oncology patients, and transplant candidates. Or where there have been 2 or more FNHTR in the past, or where the patient is likely to need multiple blood transfusions.

·  Paediatric red cells:  All are leucodepleted, irradiated and CMV antibody negative. Issued in Quad Packs (one adult unit divided into four packs)

·  Phenotyped: For patients requiring specific antigen-negative components; for example a patient with an anti-Fya  antibody needs Fya negative blood.

·  Washed:  To reduce plasma content for patients with severe allergic reactions to blood. These patients have often had many previous transfusions eg.Thalassaemia major.

Platelets

·  All platelets in Victoria are irradiated and leucodepleted, however this does not always apply if the cells come from interstate.

·  Apheresis: Prepared from a single donor, usually for and oncology/haematology patient who is refractory to pooled platelets or has opther special needs.

·  CMV antibody negative: Used for haematology/oncology patients who are CMV antibody negative; all pregnant patients; and all neonates (or intrauterine transfusions).

·  HLA matched apheresis: Collected by apheresis (single donor) and requires advanced notice to the Red Cross Blood Bank.. Used for patients who have developed HLA antibodies. The patient needs a current antibody screen and HLA typing. It can also be used to reduce the risk of further allo-immunization and in transplant patients.

·  IgA deficient:  Rarely needed. Used for patients with anti-IgA antibodies.  Red Cross Blood Bank needs 48 notice.

·  Paediatric:  Small 40 ml units of platelets.  For neonates and young children. Prepared from a single whole blood donation, or split apherresis unit .

·  Pooled platelets:  From 4 donors, for routine transfusions in larger children and adults.

About blood

Storing it

·  An allogeneic blood transfusion from a donor is a living organ transplant.

·  Note the spelling of allogeneic. (Allogenic is a geological term.) 

·  Blood may be kept for up to 3 weeks in a special refrigerator.

·  During blood’s stay in a refrigerator it suffers storage lesion. Progressively potassium leaks out of cells, they grow older, degenerate and die.

·  If your patient is bleeding, then ask for 4-day old blood – it clots better.

·  Red cells stored for more than a few days lose 2,3 DPG. Although haemoglobin picks up oxygen it will not let it go in the tissues. This causes relative anaemia, and is a reason to aim for about 20% higher haemoglobin, than you otherwise would. The older the blood, the worse the effect. Once inside the patient’s circulation three-week old blood takes 18 or more hours to recover its oxygen releasing capacity.

Ordering it

·  Fill out the blood bank forms in full detail – everything they ask for, otherwise they may not cross-match blood. This leads to a lot of unnecessary unpleasantness.

·  Cross-matching is a trial transfusion in a test-tube.

·  Automated cross-matching takes about 20 minutes.

·  If the patient has unusual antibodies in their blood, cross matching may take hours.

Giving it

·  Run blood through its own line and never add drugs to it.

·  Giving >2 units?  Then warm the blood with an in-line blood warmer

·  Never put a pack of blood in warm water, or a microwave oven!

·  Give it as fast as possible, preferably < 2 hours. It rapidly dies at room temperature.

·  Before putting up a blood product invert the bag a few times to mix it.

·  Don’t bother with micro-aggregate (20 – 40 µm) filters for routine blood transfusions, but use them in massive transfusions to prevent cellular debris trashing the lungs.

·  To prevent bacterial contamination change the giving set every 12 hours.

Reactions to it

·  Signs of blood transfusion reactions are those of acute allergy with:

·  fever

·  tachycardia,

·  sweating,

·  and urticaria.

·  Additionally severe reactions get loin pain, hypotension, oliguria, haematuria.

·  Most fatal transfusion reactions are caused by clerical errors: the wrong blood was given to the wrong patient. 

·   Do not directly mark IV bags with solvent marking pens because the ink may penetrate and contaminate the solution.

Blood groups

People have antibodies against the groups they do not have themselves.

Some patients bleed to death

Every year somewhere in a Melbourne teaching hospital surgical ward a patient bleeds to death before haemorrhage is diagnosed.  Concealed bleeding into peritoneum, pleura, or large muscle masses is difficult to diagnose unless you are vigilent. The pelvic cavity can hide 6 litres of blood with no problem. A litre or more of blood can easily hide in the muscle mass around a hip without little sign of swelling.  Measuring abdominal girth is (if you think about the maths) not going to reveal much.

b     Little gems

·  Blood pressure does not fall in haemorrhagic shock (especially in young people) until death is near.  Don’t make the fatal mistake of relying on BP to diagnose bleeding.

·  Poor peripheral perfusion is a good sign of volume depletion.                

·  A rising pulse rate is a worrying sign.

·  Postural hypotension is an excellent sign. If blood pressure falls > 20 mmHg when you raise the head of patients’ beds, then they may well be bleeding, and are almost certainly hypovolaemic.

·  A falling urine output is a good sign of bleeding or volume depletion.

·  Hypovolaemia maims and kills.  But should you give too much fluid – the pulmonary oedema is at least treatable. Death is not. Get help!!

How much blood to cross-match for elective surgery

Abdominal lipectomy

2

 

Lumbar fusion + graft

2

Abdomino-perineal resection

3

 

Lumbar fusion – no graft

G+H

Adrenalectomy

2

 

Lumbar sympathectomy

G+H

Amputation - above knee

G+H

 

Lung – lobectomy

2

Amputation - below knee

G+H

 

Mammoplasty - reduction <1 Kg.

G+H

Anterior resection

2

 

Mammoplasty - reduction >1 Kg

2

Aortic aneurysm - elective

3

 

Mastectomy + axillary clearance

2

Aorto-femoral bypass

4

 

Mastectomy – radical

2

Aorto-iliac bypass

4

 

Mastectomy – simple

G+H

Appendicectomy

Nil

 

Menisectomy

Nil

Apronectomy

2

 

Myomectomy

G+H

Arthroscopy

Nil

 

Nephrectomy – simple

2

Bowel resection

2

 

Nephrectomy for cancer

4

Burns debridement

Lots

 

Nephrolithotomy – open

4

Caesarean section

G+H

 

Nephrolithotomy- fibreoptic

G+H

Carotid endarterectomy

G+H

 

Oesophagectomy

4

Cholecystectomy – laparoscopic

G+H

 

Ovarian cystectomy

G+H

Cholecystectomy – open

G+H

 

Pancreatectomy – partial

4

Colostomy

G+H

 

Pancreatectomy – total

6

Cystectomy

4

 

Pancreatic cyst

2

Cystoscopy

Nil

 

Parathyroid

G+H

D&C ± hysteroscopy

Nil

 

Parotidectomy

G+H

Ectopic – ruptured

4

 

Pelvic clearance

4

Ectopic – simple

G+H

 

Pleurectomy

2

Femoral-popliteal bypass

2

 

Pneumonectomy

4

Femoro popliteal bypass

2

 

Porto-caval shunt

4

Gastrectomy

2

 

Prostatectomy – open

2

Gastric – high reduction

G+H

 

Pyelolithotomy

2

Gastric stapling

G+H

 

Pyeloplasty

G+H

Gastrostomy

G+H

 

Renal artery repair

3

Haemorrhoidectomy

Nil

 

Salphingoplasty

G+H

Harrington’s rods

4

 

Shoulder –arthroplasty

G+H

Hepatectomy

6

 

Spinal fusion

2

Hiatus hernia - transthoracic

2

 

Splenectomy

2

Hiatus hernia repair

G+H

 

Splenectomy for ITP

4

Hip replacement

3

 

Synovectomy – knee

G+H

Hysterectomy - abdominal

G+H

 

Termination of pregnancy

G+H

Hysterectomy -  radical

2

 

Thymectomy

2

Hysterectomy – vaginal

G+H

 

Thyroidectomy – simple

G+H

Ilio-femoral bypass

2

 

Thyroidectomy for cancer

G+H

Ileostomy or jejunostomy

G+H

 

Thyroidectomy for goitre

G+H

Incisional hernia

G+H

 

Tubal ligation

G+H

Infra-inguinal vascular redo

2

 

TURP

G+H

Inguinal hernia

Nil

 

Uretolithotomy

G+H

Inguinal hernia - laparoscopic

G+H

 

Vaginal repair

G+H

Knee replacement

1

 

Varicose veins

G+H

Laminectomy

G+H

 

VATs

G+H

Laminectomy + fusion

4

 

Vulvectomy – radical

4

Laparoscopy

G+H

 

Vulvectomy - simple

2

 

 

 

Whipple’s operation

6

 

Cardiopulmonary unit

Quick summary

Coronary artery disease                                     +        48

·  Known treated chronic stable angina needs no further investigation.

·  Patients who have previously undiagnosed IHD need investigation and optimization before anaesthesia.

·  Post-AMI, post CABG, or PTCA: Wait at least 6 weeks for semi-urgent surgery, and at least 3 months for elective surgery (or as long as possible).  If recent stress test does not indicate myocardium at risk then the likelihood of reinfarction after noncardiac surgery is low.                                             +         50

·  Where possible start patients on beta-blocker (atenolol) before surgery, and continue for at least a month after surgery. Aim for a pulse rate of 60 - 70 bpm.

Cardiac arrhythmias                                  +        53

Asymptomatic ventricular arrhythmias including couplets, and non-sustained ventricular tachycardia are not associated with increased cardiac complications after non-cardiac surgery.

Supraventricular arrhythmias

If supraventricular arrhythmias appear either during or after operation control them with beta-blockers.  These are more effective than either digoxin or calcium channel blockers

Ventricular arrhythmia

·  Need control only if associated with left ventricular dysfunction (ie. decrease in blood pressure or decreased perfusion) or threatened myocardial ischaemia.

·  Frequent VEs or asymptomatic non-sustained ventricular tachycardia are not associated with an increase in perioperative MI or death.

·  If these arrhythmias occur you must eliminate the underlying cardiopulmonary disturbance, drug toxicity, or metabolic derangement (especially magnesium, potassium, calcium, and phosphate imbalance as well as thyroid disease).

Bundle branch blocks

Minor conduction disturbances such as bundle branch blocks of first degree atrioventricular blocks usually don’t need further work up.

Pacemakers

Check before and after surgery.                                     +          57

Heart failure                                                          +        58

·  Minimal surgery            should be able to lie flat.

·  Minor surgery               must be able to sustain MET 2

·  Major surgery   must be able to sustain MET 4

·  able to lie flat without orthopnoea;

·  have < 1 cm ankle oedema;

·  have no raised JVP;

and

·  apart from atrial fibrillation, have no ventricular arrhythmias;

·  heart size within normal limits;

·  no third heart sound;

·  no signs of pulmonary congestion or upper lobe diversion on their CXR.

 

If the patient does not fulfill all these criteria, then postpone and optimize.

Who do I refer the patient to?

·  Patients with signs of mild right heart failure (ie. ankle oedema and a JVP <4 cm) can be referred back to their LMO for control. 

·  Refer urgently to a physician within the hospital those who are orthopnoeic, have a raised JVP, or signs of pulmonary congestion on their chest X-ray or symptoms such as nocturnal wheeze or cough. 

Hypertension                                                       +        47

 (       Fast forward

Minimum requirements for elective anaesthesia?

·  Diastolic blood pressure <100 mmHg;

·  Systolic blood pressure <180 mmHg just acceptable;

·  For patients with IHD, CCF, or peripheral vascular disease <160 mmHg;

·  No signs of cardiac failure, no ventricular arrhythmias;

·  No AMIs, TIAs or strokes within the past 6 months.

 

Hypertension + dyspnoea = no anaesthetic.

Who do I refer the patient to?

·  Carotid endarterectomy refer hypertensive patients to a specialist physician.

·  Diastolic blood pressures >100 – refer to LMO;

·  Systolic blood pressures >= 160 mmHg — refer to LMO;

·  Patients with symptomatic hypertension — refer to Emergency.

·  Refer all patients presenting for vascular surgery to a specialist physician.

 

Aim for systolic levels <140 mmHg

diastolic levels <80 mmHg

pulse pressures < 60 mmHg..

Cardiac work-up

How to PASS the evaluation

To evaluate and pass patients as fit for anaesthesia and surgery assess:

·  Patient risk

·  Activity level – measured in METS

·  Surgical risk

·  Select tests that are needed

What is PACE

PACE = Perioperative Adverse Cardiac Events. Includes: hypotension, arrhythmia, cardiac failure, acute pulmonary oedema, ischaemic episodes, myocardial infarction, or cardiac arrest.

1.  Patient risk

Major predictors for PACE

·  Unstable coronary syndromes – unstable or severe angina

·  MI within past 3 months

·  Untreated or severe CCF

·  High grade arrhythmias causing symptoms

·  Valvular heart disease causing symptoms.

Intermediate predictors for PACE

·  Stable angina

·  Previous MI or Q-waves on ECG

·  Treated CCF.

·  Diabetes > 5 years (or if HbA1C >8%)

·  CKD Stage 3 or less.

Minor predictors for PACE

·  Old age (physiologically speaking)

·  Abnormal ECG – bundle branch blocks, ST-T abnormalities

·  Asymptomatic rhythm other than sinus eg. AF or < 5 VEs a minute

·  MET score 3 for major surgery or  2 for minor surgery.

·  Activity level

·  Use the METs scale.  Walling up two flights of stairs (one floor) without being puffed at the top is the safe cut-off point for major surgery. This is equivalent to 4 METs

2.  Activity levels

Use the MET score                                                                    +        28

 

Roughly, 1 MET = amount of oxygen a normal adult uses at rest,  2 METS = the amount they use when walking at a rate of 2 km per hour,  ….  12 MET when they are jogging at 12 km per hour. 

·  The risk of PACE depends on what sort of shape their heart and lungs are in before the patient comes to surgery. It really doesn’t matter what is wrong with the patient’s heart, but only what sort of workload it can attain and sustain.

·   If their cardiopulmonary unit can achieve a working output sufficient to carry 7 Kg up 2 flights of stairs without being breathless at the top then postoperative cardiac problems are unlikely.

3.  Surgical risk

High risk (PACE > 5%)

·  Aortic vascular surgery

·  Infra-inguinal vascular surgery

·  Procedures > 2 hours

·  Blood loss

·  Anastomotic bowel surgery

·  Upper abdominal surgery

Intermediate risk (PACE 1 – 5%)

·  Carotid endarterectomy

·  Head and neck surgery

·  Lower abdominal surgery eg. total abdominal hysterectomy

·  Intrathoracic surgery

·  Prostate surgery lasting > 45 minutes

Low risk (PACE <1%)

·  Laparoscopic surgery

·  Endoscopic procedures including routine prostates

·  Superficial surgery

·  Breast surgery           

4.  Select tests

(      Fast forward

Use the HIP Fast forward for patients who are to have high risk or intermediate risk surgery to determine who needs careful cardiac evaluation and possible further formal cardiac workup.  Patients for low risk surgery can usually proceed without cardiac workup. 

·  High risk surgery eg. major bowel surgery, hip surgery, major vascular surgery.

·  Intermediate predictors eg. previous MI > 6 months, diabetes > 5 years (or HbA1C 8%). CKD stage ≤ 3 (eGFR < 50 ml/min/1.73 m2 .

·  Poor functional status with MET score < 4.

Pulse oximeter stress test

If a patient has two out of the three HIP variables then do a pulse oximeter stress test. The test reflects the rise in their cardiac output as they exercise. Ask nurse for the pulse oximeter. Firstly, measure their pulse rate and SaO2 at rest. Then exercise them and record the minimum levels their SaO2 falls to, and the maximum rate their pulse rate rises.

The best test is to walk up 3 flights (1.5 floors) of stairs. However many can’t manage; instead use a 50 metre walk and talk test.  Walk them as fast as comfortable and get them to talk at the same time.  Don’t allow them to become breathless. If their SaO2 falls by >5% or their pulse rate rises to >110 bpm organize formal cardiac function studies.

 

Background stuff

To read when you have time.

 

,       Fast facts

·  Congestive cardiac failure is easy to diagnose – they get one or more of the following breathless climbing stairs, they dislike lying flat, they have swollen ankles, creps in their lungs and they get up more than once to pee at night.

·  Congestive cardiac failure kills more postoperative patients than IHD.

·  Ischaemic heart disease is often difficult to diagnose and often occult.

·  Diabetics with retinopathy nearly always have ischaemic heart disease.

·  Diabetics with eGFR < 50 ml/min/1.73m2 usually have ischaemic heart disease.

·  Any patient with eGFR < 30 ml/min/1.73m2 has ischaemic heart disease.

·  Big surgery is more likely to cause PACE than little surgery.

   

`      Physiological foundations

·  Unless oxygen reaches your patient’s mitochondria, they will die. There is a chain of events where the heart, lungs and circulation act to sequentially pass oxygen from one link to the next. This oxygen transport system demands good lung function, adequate cardiac output, enough functioning haemoglobin, and favorable metabolic conditions (temperature, pH, electrolyte balance). Failure in any one component of the chain, limits oxygen transfer.

·  You can give anyone a haircut, or remove a splinter, but a total hip replacement in patients with severe heart disease is simply folly.  Why?  Because all surgery damages tissue, and major surgery damages more tissue. Major surgery generates a big systemic inflammatory response (SIRS).  As the traumatized tissue gets inflamed its blood vessels dilate.  With less resistance to push against the heart must increase its output to maintain blood pressure.  If, at best, a sick heart can just deliver an enough output to permit someone to make a cup of tea without getting short of breath, then when the heart has to increase its output to perfuse several kilograms (or more) of inflamed tissue, it will either fail or become ischaemic or both. 

·  A cystoscopy damages less tissue than a knee replacement (3 - 4 Kg), which in turn causes fewer problems than a hip replacement (8 - 12 Kg).

·  Major intra-abdominal surgery is seriously bad news. Postoperatively oxygen consumption increases by 40% (from 110 to >170 ml/Kg/min). To meet the increased oxygen demands the cardiac output to rise. In the case of upper abdominal surgery 10 or more kilograms of guts are involved. Bowel doesn't like being pushed around, much less squeezed, clamped, cut and sewn.  As rhe gut and its peritoneum beomes inflamed up to 50% of the cardiac output is shunted through the injured tissue. Merely to maintain the blood pressure the heart needs to double its resting output – a “big ask” for a sick heart.

·  Infra-inguinal vascular surgery renders a whole limb (20+ kilograms) ischaemic for a time. Whole leg ischaemia causes whole leg inflammation.  To maintain blood pressure postoperatively the cardiac output has to rise according – this is a big ask!

·  Problems mostly occur on the second postoperative day (when the inflammatory response peaks), especially around 2.00 am (when the patients’ vascular volume reaches its maximum and you are in your deepest sleep).

·   

·  Although the mass of tissue damage is the main predictor of problems other things are involved with the perioperative stress response such as pain, hypothermia, fluid imbalance, intercurrent disease, and drug therapy, nutritional state, sepsis, cytokines, acid-base imbalance, electrolyte problems, renal function; and not forgetting psychological factors play an impressive but under appreciated part.

 

The High Five

 The big five cardiovascular problems are:

1.      Hypertension;                                              +   47

2.      Ischaemic heart disease;                             +   48

3.      Cardiac arrhythmias;                                   +   53

4.      Cardiac failure;                                           +   57

5.      Valvular heart diseases.                              +   61

1.  Hypertension

Uncontrolled or suboptimally controlled hypertension is associated with PACE.  The “safe” blood pressure is unknown and anaesthetists disagree among themselves on what is “safe”.  Some will anaesthetise patients with diastolic blood pressures up to 115 mmHg, while others are concerned about pressures greater than 160/90. The following is safely conservative.

(      Fast forward

Acceptable levels

·  Diastolic blood pressure <100 mmHg.

·  Systolic blood pressure 180 mmHg is barely acceptable for minor surgery.

·  Maximum BP is 150/90 mmHg with IHD, angina, stable cardiac failure, or vascular disease.

What to do

·  No ventricular arrhythmias; and no TIAs or strokes within the past 6 months.

·  BP >160/90 and a pulse rate >65 then consider adding a b-blocker before anaesthesia. Use atenolol; start with 50 mg in the morning.

· 

·  Refer suboptimally controlled hypertension to the LMO.  But if the patient is having vascular surgery refer them to Hypertension Outpatients at BHH for control, and not back to their LMO. It is the reduction in BP that counts, and not what drug is used to achieve this.

·  For elective anaesthesia allow at least 3 weeks for their baroreceptors to re-calibrate to the adjusted blood volume after commencing or changing antihypertensive medication.

·  Don’t stop ß-blockers, or antihypertensive therapy before surgery. Some authorities suggest stopping ACE inhibitors and ARBs on day of surgery.  This is probably not worthwhile, because they have very long half-lives.  

b         Little gem

            Hypertension + dyspnoea on exertion or at rest = no anaesthetic

What to do with white coat hypertension

White coat hypertension (WCHT) isn't benign. Refer to LMO for control before surgery.  If the patient’s BP rises on seeing a white coat, it goes stratospheric on seeing a green gown and mask.  Postoperatively it is a major risk factor for PACE. Consider an anxiolytic premedication (eg. temazepam 10 mg 40 minutes before going to theatre).

`      Physiological foundations

·  In patients with hypertension, the heart works harder than normal. Hypertensive patients are more likely to develop cardiac ischaemia or failure with surgery and anaesthesia.

·  Most of the problem is revealed by the pulse pressure (not the systolic or diastolic pressure).  Diseased arteries are stiff.  As the pulse wave passes like a hammer-blow through them the rigid walls do not “cushion“ the pulse as more elastic vessels do.  This excess energy is passed on to cause high pulse pressures. 

·  If the pulse pressures >80 mmHg then control it before surgery. 

·  A heart pumping blood at 120/80 mmHg  (pulse pressure = 40 mmHg) is doing roughly half the pressure work of a patient heart that is 150/70 mmHg (pulse pressure = 80 mmHg). 

·  It’s the reduction in blood pressure that counts, not the class of drugs used to reduce it.

2.  Ischaemic heart disease

We absolutely must identify ischaemic heart disease before major surgery. Patients with IHD are at much higher risk of postoperative AMI.  Postoperative mortality (up to 50%) is far higher than “off-the-street”mortality with AMIs (4 - 6%). If postoperative myopcardial ischaemia is recognised in time, many MIs can be avoided. Unfortunately about half postoperative myocardial ischaemia is silent – no pain. Patients just go grey and sweat, then collapse and die.  However if the patient is admitted to an ICU as soon as the warning signs develop then the mortality rate drops from 50% to about 15%. The message is detect myocardial ischaemia early and get your patient into ICU.

In 2002 the American Heart Association (AHA) issued guidelines for perioperative cardiovascular evaluation of patients presenting for non-cardiac surgery. These “Gold Standards” give inconsistent advice and are now out-of-date. They were issued before drug-eluting stents arrivedon the scene, and times they give inconsistent advice. 

(      Fast forward

Treated stable chronic IHD

·  Treated stable angina with a MET score of 3+ can proceed with surgery without further workup.

·  CABG or stent in past 5 years with stable IHD and a MET score of 3+ can proceed without further workup.


Record in notes

·  What triggers their angina: exercise, emotion, postprandial, nocturnal, or spontaneous.

·  What MET score they can attain and then sustain.

·  Check their medication; it should include:

·   aspirin (60-50 mg daily),

·  a statin (eg. atorvastatin 10 mg nocte),

·  an ACE inhibitor (ramipril ),

·  a ß-blocker (atenolol 50 mg daily)

·  and a GTN patch or sublingual tablets prn. 

·  For elective surgery maintain everything but the aspirin. (Most units in other hospitals keep their patient on aspirin and a statin).

·  Undue anxiety can kill. Reassurance is very important. Explain every step along the way. Give a premed of temazepam 10 mg 50 minutes before surgery. Apply a GTN patch. Consider giving them oxygen on the way to theatre.

·  Use a b-blocker unless otherwise contraindicated. Contraindications include: asthma, peripheral vascular disease, pulse rate < 60 bpm).  Longer acting atenolol is better than short acting metoprolol. Give atenolol 25 - 50 mg daily for 4 days preop, then increase to twice daily after the operation. Probably wise to continue beta-blockade indefinitely. 

·  Use a LMWH postop. 

Who to investigate

·  Known, thoroughly investigated and fully treated chronic stable angina needs no further investigation, because there is little more that can be done. 

·  Tell your patient of the risk, and make a plan for postoperative care. 

·  Perioperative ECG monitoring in high-risk patients substantially reduces mortality.

·  If recent stress echocardiogram does not indicate myocardium at risk then the likelihood of re-infarction after noncardiac surgery is low.

What to do if you discover angina

Those with previously undiagnosed IHD need investigation:

·  stress echocardiography if they can walk;

·  dopamine stress echo if they cannot walk;

·  thallium scan if they are obese (BMI >35) or cannot lie for 20 minutes on left side.

·  then refer them to a cardiologist.

Patients sometimes develop angina in the clinic

If someone sitting in front of you is clutching their chest consider acute ischaemia. Every few months someone develops unstable angina in Preadmission Clinic and needs to be transferred to Emergency Department.  Anginine and oxygen are kept in the department.

Risk factors for IHD

Risk factor

Score

Sex

 

Male aged > 55 years of female aged > 65 years

9

Male aged 40- 55 years, female aged 50 - 65 years 

6

Male aged <40  years, female aged <50 years 

3

Chest pain

 

Angina?

5

Atypical angina (para-angina)?

3

Non-anginal (atypical) chest pain?

1

Diabetes

 

Diabetes?

2

Retinopathy?

5

Lipids

 

High lipids

2

Family history

 

Positive in relatives > 60 years

1

Positive history in first degree relatives < 60 years

3

Obesity

 

BMI >= 30

1

Hypertension

 

SBP > 140 or diastolic BP > 90

1

 


Score   <9       risk if significant IHD                  low

            10 - 15  risk of significant IHD                 moderate

             >15     risk of significant IHD                 high

The important 40% rule

 

40%    of patients

With IHD have few or no risk factors;

With IHD don't get classical angina;

With IHD normal looking ECGs;

With vascular disease have severe IHD;

With diabetes >10 years have IHD;

Smokers >40 years have IHD

How to diagnose angina

· 

· 

·  Not everyone with severe IHD gets retrosternal chest pain on exertion.

·  Emotional stress (noradrenaline mediated) is more likely to cause angina than exercise  (adrenaline mediated).

·  Don't ask blunt questions like; "Do you get chest pain?", because most Aussie blokes will immediately slip into denial ("It's my indigestion, Doc").  Instead sneak up with questions about "chest discomfort" when they get "upset", then slide gently into questions about their exercise tolerance.

·  Use the MET score to quantify exercise capacity                                   +   29

·  Don't be reassured by a normal resting ECG.

·  Don't be reassured by the absence of risk factors.

·  Coronary angiography is not infallible. A patient can have epicardial coronary arteries you could drive a truck through, but still have microvascular heart disease.

·  If they have diseased vessels in their retina (diabetic or hypertensive retinopathy), then they have disease microvasculature in their heart, their kidneys and brain too.

·  Similarly, if they have a creatinine clearance <30 ml/min, then assume they have IHD.

 

b         Little gem

Any pain, anywhere, above the umbilicus that comes on with exercise or emotional stress, which is relieved by rest or nitroglycerine, is angina.  The pain or discomfort or pressure or ache can occur in the arms, jaw, top of the head, throat, epigastrium - anywhere north of the belly button. It may even present like cholecystitis.

What are the risks of perioperative infarction following a prior MI

·  The risk of perioperative problems depends on the functional state of the patient’s myocardium rather than how long ago they had their infarct. 

·  Good preparation for anaesthesia and scrupulously careful postoperative monitoring reduces the risk of postoperative infarction.  Still postoperative MI is bad, bad news.  Once the patient has had an MI their chance of dying is about 50%. 

·  It is prudent to wait 6 months after an infarct.  Urgent surgery can be performed after 3 months with little risk but only if the patient can exercise to and sustain 3+ MET.

·   

AMI 

Risk

0 - 1 month ago

>70%

1 - 3 months ago

30%

2  -6 months ago

15%

> 6 months ago

6%

About cardiac stents

(      Fast forward

·  After bare metal stents (BMS) wait at least 6 weeks for semi-urgent surgery and at least 3 months for elective surgery

·  After drug eluting stents (DES) defer surgery for  6-12 months.

·  Unless contraindicated leave patients on their aspirin.

·  Maintain their statins.  They should be taking a beta-blocker, and an ACE inhibitor.

,             Fast facts

 

·  Blood coagulability increases at least 5 to 7 fold following major surgery.

·  Clots are useful in the right place. But, with the prothrombotic state following surgery, clots tend to form inconvenient places – plaques on coronary vessels, leg veins etc.

·  Partially blocked coronary arteries can often be unblocked. Percutaneous coronary angioplasty (PTCA) can be done 2 ways: 1). stents and 2). balloon angioplasty. All PTCAs injure endothelium.  Injured epithelium proliferates; cells pile up on one another to form mounds that degenerate into jagged plaque where clots can form. 

·  There are two types of stents:

o   Bare metal stents (BMS).

o   Drug-eluting stents (DES).

·  Both are prone to form clots.

·  Problems with stents seem to be either clots forming sooner, or clots forming later.  BMS are prone to form clots sooner - in the weeks following their insertion.  In an attempt to overcome this problem DES are impregnated with either tacrolimus, (a cytotoxic antibiotic), or paclitaxel (an anticoagulant).  DESs leave a raw area on the adjacent coronary artery wall that can take up to 12 months to heal. This raw area is a perfect place for clots to develop months later. For this reason it is hazardous to stop clopidogrel in the interim because patient may infarct. 

The controversy

·  Post DES defer surgery for as long as possible. How long to wait is uncertain, but cardiologists feel endothelium is unstable for at least 12 months; that is why they prescribe clopidogrel + aspirin for this period. The risk period for AMI after DES (tacrolimus) definitely lasts for at least 3 months, probably 6 months, and possibly for ever.  For DES (paclitaxel) the risky period is probably for a lifetime.

·  If surgery is essential then leave the patient on aspirin – they lose a little more blood, but do not seem to require more blood transfusion. Clopidogrel is different story; they do require more blood, and their hospital stay is longer, but some authorities [BMJ 16.12.06] recommend patients stay on clopidogrel. Discuss options with the surgeon.

About coronary artery bypass graft (CABG)

(      Fast forward

·  It is prudent to wait for at least 3 months after CABG for elective surgery. 

· 

· 

·  A patient who has had a CABG in the last 5 years, and is now symptom free can be considered as a having normal perioperative risk.

·  If a patient with previous CABG is symptomatic then investigate them before surgery.

Types of angina

What is unstable angina?

Unstable angina (USA) is defined as angina that

·  has got worse in the past 3 months;

·  now requires more medication than it did a few weeks ago;

·  comes on spontaneously without trigger factors - for example while watching TV;

·  occurs at night or wakes patients from sleep.

 

b         Little gem

            Unstable angina is an absolute contraindication for elective surgery. 

            Send the patient to the Emergency Department.

What is para-angina?

· 

·  About 40% of patients with serious ischaemic heart disease do not get chest pain (or discomfort, or pressure).  Smokers and diabetics may have infarcted the hair-like blood vessels supplying nerves carrying cardiac pain sensation.


·  their heart's demand for oxygen, exceeds the ability of the coronary vessels to supply it.  They no longer get the warning pain of angina; instead , without an adequate coronary blood flow, their cardiac output abruptly falls. Then abruptly, they feel: faint ("dizzy"), or fatigued, or breathless, This forces them to stop what they are doing and rest until they feel better. Observers say they go grey and often sweat.

·  Shopping malls and church are superb cardiopulmonary stress tests for the elderly.  There are ramps, long distances to walk, parcels to carry and nowhere to sit down.  In any big mall you will see elderly people, looking grey, slumped over their carry-bags.  Another good cardiac function test is church - all that standing up, and sitting down, and holding their breath as they sing; and in some cases - emotional stress.  Like the devout man admitted to CCU that Sunday morning after his wife took a seat in church next to his mistress.

·   

Postoperative management of IHD

b     Gems about IHD

·  Most anaesthetists remember a patient who had an MI on the way to theatre. Site a GTN patch before they leave the ward.

·  Allow them to have their GTN spray under their pillow.

·  Anxious patients profit from a premed of 10 mg temazepam 50 minutes before transport and oxygen on the way to theatre.

·  Hypothermia in the recovery room (<36.5°C) warns of bad things to come in the ward.

·  Long operations carry more risk than shorter operations.

·  The bigger the surgery the greater the risk of mtyocardial ischaemia.

·  The more tissue damage the greater the risk. Don’t forget prolonged tourniquets and vascular clamps render whole limbs ischaemic. Once the clamps come off cytokines, tissue debris, lactic acid and all sorts of ischaemic factors flood the circulation.

·  Bowel preps debilitate older sick patients setting off for the greatest physiological challenge of their life.  Re-hydrate them before surgery. Consider how a marathon runner would perform after being up all night on the toilet with diarrhoea.

·  ST-changes in the recovery room forewarn of myocardial ischaemia later in the ward.

·  Ischaemia usually occurs on or about the 2nd postoperative day, and frequently in the early hours of the morning;

·  Routine postoperative ECG can pick up signs of ST depression and impending ischaemia about 12 hours before the event.  It is useful to do them at 08.00 hr and repeat them late in the afternoon for the first 60 postop hours in high risk patients.

·  Omit diuretics on the day of surgery, because they predispose to intraoperative hypovolaemia and tachycardia.

·  Tachycardia in a patient with ischaemic heart disease is a bad thing and a good reason to maintain ß-blockade;

·  Hypertension (or high pulse pressures) in a patient with ischaemic heart disease is a bad thing and a good reason to maintain their antihypertensive therapy and carefully attend to their fluid balance.

·  Hypertension + tachycardia in a patient with IHD are a disaster.

·  Watch for cool hands - a sign of a panicking hypothalamus.      

`      Physiological foundations

Endothium is busy, busy, busy

Endothelium is not simply a film of ten trillion (1013) cells lining the blood vessels. It weighs a kilogram (the third largest organ) and secretes stuff to help blood clot (von Willebrand’s factor and prostaglandins); to relax smooth muscle (nitric oxide), and to constrict smooth muscle (endothelin).  Also endothelium produces and reacts to various cytokines, and adhesion molecules, and mounts both pro- and anti-inflammatory responses. Additionally, these front-line cells are frenetically active; they incessantly move apart allowing white blood cells in and out of the circulation, and to patch up damage caused by the constant pounding they receive from pulse pressure.  

Patients with recent AMIs, CVAs, TIAs, DVTs or major surgery have “sick endothelium”, which is prone to nurture clots everywhere. When circulating "nasties" contact endothelial cells the cells become twitchy. They either shrivel up into miserable little balls - exposing adjacent basement membrane - or they proliferate, stacking-up on each other eventually forming vascular plaques.

Surgery damages tissue. In response the body launches a chemical counter-attack to prepare the way for tissue repair.  Its arsenal includes circulating cytokines, membrane attack complexes (a MAC attack), complement, catecholamines, and a host of other inflammatory and immunological factors such as cytokines, interleukines (especially IL-6 and IL-8), excessive glucose, certain fatty acids and prostaglandins.

What are the consequences of the endothelial syndrome?

Sick endothelium has been given the name of the endothelial syndrome. Its most obvious consequences are clots - thromboses.  After MI or stroke the endothelium takes a long time to settle down to a healthy state.  How long this takes is unknown, but it certainly takes 3 months, probably 6 months and possibly longer. This means that if a patient has had CVA or TIA in past 3 months, and they undergo surgery then they are something like 15 times more likely to have another one. They also have an increased risk of an AMI, or DVT as well, but what the chance of these latter events is just not known. Statins help the endotheli um cope with its continual exposure to passing toxins in the blood stream.

3.  Cardiac arrhythmias

An irregular pulse indicates an arrhythmia, and an arrhythmia suggests cardiac disease, and that is most likely to be ischaemic heart disease, or possible valvular heart disease.  Patients with preoperative arrhythmias have an increased risk of PACE. 

(       Fast forward

· 

·  Frequent VEs or asymptomatic non-sustained ventricular tachycardia in a patient >60 years are not associated with an increase in perioperative MI or death. 

·  Control supraventricular arrhythmias with a b-blocker before surgery.  Optimal heart rate for surgery is 55 – 80 bpm.

·  You need to control ventricular arrhythmias only if they are causing problems of hypotension or decreased tissue perfusion; or there is actual or threatened myocardial ischaemia.

·  Multifocal ventricular ectopics indicate irritable myocardium. Asymptomatic ® cardiologist.  Symptomatic ® Emergency department.

·  Eliminate the underlying cardiac or lung pathology, drug toxicity, metabolic problems: magnesium, potassium, calcium, and phosphate imbalance and thyroid disease.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia seen in Preadmission clinic.  To maintain postop BP the optimal ventricular rate for surgery is about 80 – 85 bpm.

What are the causes of atrial fibrillation?

Mnemonic ARRHYTHMIC

A = Alcohol;

R R = Rheumatic heart disease;

R = Regular ischaemic heart disease;

HH = Hypertension;

Y = mYxoma — atrial;

T = Thyrotoxicosis;

H = Haemochromatosis;

M = Mitral valve disease;

I  = Infective endocarditis;

C = Cardiomyopathy.

 

These occur in the following order of frequency: heart failure, cardiac ischaemia, hypertension, cardiomyopathy, mitral valve disease, alcohol, thyrotoxicosis.

Refer to a cardiologist if

·  ventricular rate exceeds 105  bpm;

·  unevaluated mitral or aortic valve disease;

·  symptoms of  fatigue, dyspnoea, angina, or syncope;

·  MET score <3;

·  any suggestion of recent AMI.

Refer to Emergency Department if

·  chest pain;

·  pulse rate > 120 or less than 55 bpm;

·  symptoms suggesting low cardiac output either at rest or when walking on the flat.

What about cardioversion before surgery?

Cardioversion, whether with drugs or by defibrillation, carries a risk of embolic stroke.  Following electrical cardioversion the atria's endothelium is stunnedon which clots form readily.  If AF has been present for more than 48 hours then anticoagulate the patient for 3 weeks before cardioversion.  Because stroke recurrence in patients on AF is high long they require life long anticoagulation preferably with warfarin; aspirin is not sufficient.

Ventricular extrasystoles

(      Fast forward

·  If patient is normotensive and has less than 5 VEs per minute it is probable benign. They may simply be a sign that recently the patient has had a cup of coffee, or smoked a cigarette.

·  More than 5 abnormal beats per minute is a minor predictor of PACE.

·  Bigeminy occurs where repeatedly a normal beat is followed by an ectopic beat. Control it before anaesthesia either by treating the cause, or with beta-blockers. 

·  Multifocal extrasystoles, with differing QRS forms in the same lead, needs a cardiologist’s assessment before anaesthesia. 

·  If associated with angina, or near syncope, then refer to Emergency Department. 

 

,  Fast facts

·  VEs are a sign of a myocardium irritated by ischaemia, caffeine, nicotine or drugs.

·  More seriously VEs occur with hypertension (with the associated myocardial ischaemia), electrolyte abnormalities or occasionally myocarditis. 

·  Drugs causes include: digoxin, adrenoceptor agonists, tricyclic antidepressants; while diuretics causing hypokalaemia and hypomagnesaemia increase myocardial irritability. 

·  Also occurs with underlying cardiac disease, such as mitral valve prolapse, cardiomyopathies and assorted valvular diseases (especially aortic stenosis).  

·  Multiple VEs in a young person associated with ST depression in V1- 3 may indicate left ventricular dysplasia.  Needs b-blocker. This fatty infiltrate of left ventricular muscle is one of the causes of young people "dropping dead". Another reason for sudden death in young people is HOCUM.

·  Bigeminy signals more irritable myocardium than the occasional ectopic beat.  The causes include one or more of: myocardial hypoxia, hypertension, digoxin toxicity, high catecholamine concentrations, hypokalaemia or hypomagnesaemia.  

·  Bigeminy occurs where repeatedly a normal beat is followed by an ectopic beat. Control it before anaesthesia either by treating the cause, or with beta-blockers. 

·  Bigeminy signals more irritable myocardium than the occasional ectopic beat.  The causes include one or more of: myocardial hypoxia, hypertension, digoxin toxicity, high catecholamine concentrations, hypokalaemia or hypomagnesaemia.  

Postoperatively

·  Eliminate hypoxia, hypertension and myocardial ischaemia as a cause. 

·  ­If the blood pressure, and pulse rate is within normal limits, the patient's perfusion is normal, and there are less than 5 ectopics per minute, no treatment is necessary. 

·  If there > 5 VEs per minute, then consider hypertension or IHD.  

Heart rate

Tachycardia

·  Sinus tachycardia = rate 100 – 150 bpm. 

·  If > 150 bpm = SVT or VT

 

(      Fast forward

·  Ideal heart rates

·  Normal patient 60 – 70

·  Patient in atrial fibrillation 70 - 85

·  If resting heart rate > 100 postpone elective anaesthesia and investigate.

·  Best to refer to patients to their LMO for investigation

·  Consider b-blocker eg. atenolol 50-100mg daily.

Causes

·  Apprehension or anxiety; pain, fever, hypovolaemia, hypercarbia.

·  Chronic cardiac failure — especially in the elderly tachycardia is often a sign of diastolic dysfunction with high resting sympathetic drive. 

·  Ischaemic heart disease, atrial fibrillation or flutter; supraventricular or ventricular tachycardias.

·  Endocrine: thyrotoxicosis, phaeochromocytoma,

·  Drugs: atropine. ß-stimulators: salbutamol, terbutaline, anticholinergics.

 

b     Little gem

Tachycardias do not allow enough time for ventricular filling, or myocardial perfusion.  They lead to adverse cardiac events if the patient becomes hypertensive. 

Bradycardia

·  Sinus bradycardia (rate < 50)

·  ( Fast forward

·  Check for b-blockers, especially sick sinus syndrome, heart blocks, hypothyroidism.

·  If rate > 40 and no symptoms proceed with anaesthetic.

·  If rate < 40 and no symptoms refer to LMO for investigation. Send LMO the ECG.

·  If rate < 40 and symptomatic refer to emergency department.

Palpitations

· 

· 

·  Palpitations signal an arrhythmia.

·  If palpitations are associate with cardiac failure, or are causing symptoms of syncope, near syncope or excessive fatigue; or if they come on with emotional stress or exercise, or wake the patient from sleep.then postpone the anaesthetic and investigate the arrhythmia. Check thyroid function, note their medication and herbals Then order a Holter monitor and refer them to a cardiologist.

·  Half the patients describing palpitations have a cardiac cause, and of these 65% will develop perioperative problems with arrhythmias. 

·  Palpitations occur with: thyrotoxicosis, hypoxia in its various guises (ischaemic heart disease with arrhythmias, sleep apnoea). Also WPW syndrome, hypertension, drugs eg. digoxin, caffeine, smokers. 

·  Anxiety is a cause, but usually in the setting of IHD, or drugs (eg. tricyclics)

Heart blocks

Heart blocks are a sign of heart disease. This is usually ischaemic, but sometimes degenerative (which means the conducting system is strangled by fibrous tissue).  The higher the grade of heart block, the higher the risk of postoperative PACE. 

(      Fast forward

In patients with heart block postpone surgery and refer them to a cardiologist if there are:

·  symptoms of syncope or near syncope

·  sino-atrial pause > 3 seconds.

·  Mobitz II A-V block.

·  complete heat block.

·  poor exercise capacity ie. METS ≤ 2

·  Onset of heart block within past 6 months

 

Pacemaker:  Until recently those with bifasicular blocks on preoperative ECG were thought be at risk of developing complete heart block during or after anaesthesia, and were referred for elective pacemaker insertion. This is no longer necessary providing the patient is:

·  Asymptomatic with no syncope and no episodes of faintness or dizziness.

·  Has a pulse rate 60 - 85 bpm.

·  Has a MET score 3+.

·   

Significance of heart blocks

 

Significance

Action

Right bundle branch block

Usually degenerative, but can be ischaemic.

OK for surgery

Left bundle branch block

Usually ischaemic, but can be degenerative

OK for surgery

Consider IHD

Left anterior hemiblock

 A sign of anterior ischaemia

OK for surgery

Consider IHD

LAHB + RBBB ± AVB

Suggests 2 vessel cardiac disease

OK for surgery if METS 3+, Consider IHD

Left posterior hemiblock

Suggests extensive myocardial disease

Refer to cardiologist

First degree AV block

Usually degenerative

OK for surgery

Mobitz type 1 (Wenckebach)

Often degenerative

OK for surgery

Mobitz type 2

Often ischaemic

May develop complete heart block

Refer to cardiologist for assessment

Complete heart block

Serious arrhythmia

Needs pacemaker preop

Refer to cardiologist urgently or Emergency Department if symptomatic.

Sick sinus syndrome (SSS)

·  SSS is seriously serious stuff.

·  SSS is a collective term (like a murder of crows) describing a number of abnormalities inside the sinus node.

·  SSS  more commonly occurs with IHD (usually RCA), less commonly with atrial septal defects, and rarely with other forms of structural heart disease.

 

(      Fast forward

Postpone surgery and refer to a cardiologist

·  If the patient is symptomatric: near syncope, or breathless, or pulse rate < 60.

·  If they have evidence of tachy-brady syndrome

About the tachy-brady syndrome

· 

·  (Also called in reverse bradycardia-tachycardia syndrome) is a form of SSS sometimes revealing itself as intermittent atrial fibrillation with a high ventricular rate.

·  Probably need a pacemaker to control bradycardia, and antiarrhythmic drugs (sotalol or amiodarone) for the tachycardia, and anticoagulants to prevent emboli.

`      Physiological foundations

·  SSS may be a sign of sick atrial muscle too such as paroxysmal AF or flutter with episodes of bradycardia.

·   May cause inappropriate sinus bradycardia, irregular firing of the SA node, and sinus arrest with junctional escape beats. Irregular P-waves but the PR interval is normal.  Every P-wave has a QRS following it. Compare this with Mobitz II block or complete heart block where the P-wave isn't necessarily followed by a QRS. 

·  SSS more commonly occurs with IHD (usually RCA), less commonly with atrial septal defects, and rarely with other forms of structural heart disease.

Permanent pacemakers (PPM)

Two types of pacemakers: anti-tachycardia pacemakers terminate arrhythmias, and anti-bradycardia pacemakers that simulate normal pacemaker function.  There are also implantable defibrillators. 

What to check

·  Check the ECG for pacemaker spikes. One spike at the start of the QRS complex indicates ventricular pacing; two spikes indicate atrial and ventricular pacing. 

·  The patient should carry a card in their wallet with the details of their pacemaker.

·  If there are no regular pacemaker spikes, then pacemaker is either faulty, or set in demand mode. 

·  Check the pacemaker in the 24 hours before surgery, and again after surgery.  You will need to fill in the special Department of Cardiology referral-form.

·  For most pacemakers you can leave the settings unchanged.  Just before induction of anaesthesia turn off those that have the ability to cardiovert or over-pace, because the pacemaker sensors interpret diathermy interference as a tachycardia or VF.  Don't forget to turn them back on again in the Recovery room. You can turn them off and on by waving a special magnetic coil over the chest.  

·  Warn surgeon about the pacemaker so that he can use bipolar diathermy.  In contrast the unipolar diathermy stick may deliver enough current to either fry the pacemakers circuits or disrupt its function.

How to do a postoperative recheck of pacemakers

·  Get a CXR, PA and lateral. Check the electrode is wedged in apex of right ventricle. 

·  Check the ECG rhythm strip; look at lead II. Check each pacemaker spike is followed by a widened QRS (similar to ventricular ectopics). If it doesn’t then the pacemaker may be malfunctioning.

In patients with PPM

·  50% have IHD

·  20% are hypertensive

·  10% are diabetic

·  Recent episodes of dizziness or syncope almost certainly mean PPM malfunction .

4.   Cardiac failure

The commonest cause of postoperative death is heart failure.  Unfortunately heart failure may be frustratingly difficult to diagnose, particularly in elderly women or obese people.

Cardic failure + surgery = catastrophe

 

Poor endurance is the hallmark of cardiac failure.  Patients fatigue easily and become breathlessness when they exercise.  Many elderly people may not report this because they never venture further than their front door; instead the world comes to them with home-help and meal-on wheels.   Be suspicious if the answer to your question “Can you walk up the stairs?“ is “I never walk up stairs”.

Psst!     Congestive cardiac failure (CCF) strictly refers to failure with oedema.

If there is no oedema then call it heart failure.

(       Fast forward

Absolute minimum requirements for anaesthesia

· 

·  For minor surgery (METS 2)  ie. walk and talk on the flat for 50 metres.

·  For major surgery  (METS 3) ie. push a trolley around the supermarket.

·  Have no more than minimal (<5 mm) ankle oedema.

·  Have no raised JVP.

·  Be able to lie flat without orthopnoea or discomfort.

·  And have

·  no more than minor cardiac arrhythmias or conduction defects.

·  A heart size within normal limits.

·  no third heart sound.

·  no creps in the lungs.

·  no signs of pulmonary congestion or upper lobe diversion on chest X-ray.

Now 

·  If you suspect undiagnosed cardiac failure order U+Es, FBE, LFT, TSH, chest X-ray, and organise an echocardiogram . and refer back t their LMO         +   67

·  For severe disease refer them to a cardiologist.

What happens if you don’t fix cardiac failure

If patients with cardiac failure can’t increase their cardiac output to meet the metabolic demands of the tissues, then their blood pressure falls and they may well die. CHF is not a single entity, but rather a catch-all term describing a number of different phenomena. So, when physicians talk about “cardiac failure, they may not all be talking about the same thing.  The common clinical feature of cardiac failure is poor endurance; the patient gets fatigued and breathless when they exercise (and they tend to die after major surgery).

How to recognize heart failure

You won’t find some of the following points in conventional texts.

Symptoms
Signs

Dyspnoea

Orthopnoea

Nocturnal cough ® nocturnal wheeze ® Paroxysmal nocturnal dyspnoea

Poor endurance

Lethargy and easily fatigued

Ankle swelling

Anorexia ® cachexia

Tachycardia > diastolic blood pressure

Nocturia

Displaced apex beat

Persistent creps or wheeze

Pitting oedema

Third heart sound

Tender hepatomegaly

Raised JVP

Just to confuse you, each of these markers can have other causes

·  Dyspnoea on exertion can also be caused by respiratory disease, pulmonary hypertension and anaemia. 

·  Fatigue - has many many causes (eg. anaemia, renal failure, cancer, etc). 

·  Swollen ankles are caused by ECF overload, lymphoedema and fat ankles.  

·  Nocturia can also arise from urological disease and diabetes.

·  The best test of cardiac function is to measure the patient’s response to graded exercise. Record their sustainable (not attainable) exercise capacity in METS.

b     Little gems about diagnosis

·  Suspect CCF if the patients are puffing when they walk into your consulting room.

·  Nocturia.  A one pee night is acceptable; a 2 pee night is suspicious; while a 3+ pee night is highly suspicious sign of cardiac failure. But diabetes can cause nocturia too.

·  Non-specific ST and T-wave changes, on their ECG.

·  Proteinuria and low serum sodium (Na+<132) = severe heart failure

·  Night sweats - a sign of an activated sympathetic nervous system.

Markers for cardiac failure

We all know the classic triad of signs (cardiomegaly, wheeze and 3rd heart sound) and the 3 classic symptoms (dyspnoea on exertion, orthopnoea, and paroxysmal nocturnal dyspnoe) of cardiac failure. By the time patients have developed the triads, they are in desperate trouble. To keep out of trouble anaesthetists need to recognize occult cardiac failure before the stress of surgery makes it worse.  We need to dentify early markers to allow us to predict those patients who are heading for trouble. The following markers helpfully identify those patients with occult cardiac failure.

Marker

Sensitivity

Specificity

1.  Heart rate greater than diastolic BP

53%

86%

2.  Dyspnoea on walking on flat

82%

63%

3.. Abnormal ECG nonspecific ST changes,

or conduction defects.

87%

56%

4.  Peripheral oedema ® nocturia more than once

32%

97%

Abnormal results in all four factors strongly indicate severe dysfunction - for major surgery get an echocardiogram and write on the request slip “ejection fraction- please”. 

·   

What causes breathlessness?

Not all dyspnoea is the heart’s fault, but most dyspnoea is caused by inadequate cardiac output in some way or another:

·  Failure of the heart to pump adequately – either acutely or chronically:

·  Arrhythmias ® ¯ cardiac output

·  Ischaemia ® abrupt ¯ cardiac

·  Pulmonary hypertension ® ­ cardiac work

·  Severe kidney disease ® ­ BP + ­ECF volume  + anaemia

·  Anaemia ® high output with heart unable to keep up.

·  Hypothyroidism ® ¯ myocardial contractility

·  Pulmonary disease.

·   

About BNP

·  Although not used at BHH, plasma B-Naturetic Peptide levels help sort out the diagnosis in those patients presenting with shortness of breath.  BNP has a high negative predictive valuefor heart failure.  In other words if the levels are normal then the patient hasn’t got cardiac failure, but if they are abnormal they may not have failure. 

·   

What to do about heart failure preoperatively

· 

·  Control blood pressure, reduce oedema, use a beta blocker if possible to keep heart rate around 65 bpm, prescribe a statin, stop NSAIDs and COX-2 inhibitors.

·  In cases of systolic dysfunction use afterload reduction with and ACE inhibitor or angiotensin receptor blocker.

·  Check for sleep apnoea.

·  Worry if the resting pulse rate is greater than the diastolic blood pressure.

·  The patient must be able to sustain a cardiac output to work at least at 2 METs for minor surgery and 3 - 4 METs before major surgery.

·  For upper abdominal or thoracic surgery then 4 - 5 METs is preferable.

·  Subtle signs of cardiac failure and raised intravascular volume include: nocturia, night sweats, nocturnal cough or wheeze. Proteinuria is an ominous sign of long standing failure.

·  < 3 mm of ankle oedema and 3 - 4 MET exercise capacity is OK for most surgery;

·  very bad prognostic signs are orthopnoea, dyspnoea on walking up the corridor, and especially raised JVP and crackles in the lung bases; as is CXR signs of cardiomegaly and pulmonary vascular congestion.

What to do about ankle oedema                                       

·  First make sure the oedema is actually pitting.               Much more +   96

 

·   

·   

·   

·  Mild dependent pitting oedema alone is not a major hazard for postoperative PACE. 

·  Anaesthetists are more wary of peripheral oedema than are physicians, because they have to deal with the progressive rise in venous pressures during long operations as ECF is reabsorbed back into the blood stream. 

·  Myxoedema does not to pit, and lymphoedema does not pit readily.  Never take blood or insert drips into (lymph) oedematous limbs, because the holes will never seal the tissue fluid will drip out, and the patient will probably sue you.

`      Physiological foundations

·  Oedema is associated with excessive vasodilation, reduced renal function and raised extracellular fluid volume. 

·  The patient may be unable to increase their cardiac output when required, either during the anaesthetic, or in the first few days after surgery. 

·  Postoperatively their venous pressures rises, particularly when they are supine at night, The raised venous pressures can lead to pulmonary oedema.

·  Tissue oedema increases the distance between capillaries so that oxygen has further to diffuse. This is a major reason for poor wound healing, and predisposes to ulcers.

·  If the K+ or Na+ concentrations are low, then patient probably has low Mg++ levels as well.  Hypomagnesaemia increases the risks of postoperative cardiac arrhythmias and failure.

Review the patient’s therapy

The principles of drug therapy for heart failure are:

·  ACE inhibitors are the first line in therapy.

·  Diuretics give rapid symptom relief.

·  Add spironolactone (good stuff) with severe heart failure.

·  Once CCF is controlled then start a ß-blocker (preferably atenolol) in low dose. This reduces mortality.

·  Use nitrates + hydralazine where ACE inhibitors are not tolerated.

·  Although digoxin does not reduce mortality, it may decrease symptoms and hospital admissions. Digoxin is the only drug that decreases heart rate while increasing its contractility. But digoxin is toxic and consequently not very popular for heart failure.

How serious is the cardiac failure

Severe cardiac failure

Severe cardiac failure is obvious. It presents with 3 symptoms: breathlessness on exertion, orthopnoea, and paroxysmal nocturnal dyspnoea; and 3 signs: cardiomegaly, added heart sound and crackles in the lung bases. Those with uncontrolled severe heart failure are not fit for any sort of elective surgery.  Refer to cardiologist for optimization.

Mild or occult failure

One or more of the following warn of trouble: coexisting hypertension (especially in women), ischaemic heat disease (especially in men), a history of smoking, dyslipidaemia, diabetes, BMI >30, microproteinuria and hyponatraemia.

Mild or occult cardiac failure is revealed when 2 or more litres of oedema fluid re-enter the circulation when the patient lies down at night.  The raised central venous pressure triggers a progression of symptoms: restless sleep, getting up for a pee two hours after going to bed, night sweats, nocturnal cough, nocturnal wheeze and eventually paroxysmal nocturnal dyspnoea.  

Functional classification of cardiac failure

A most useful way of classifying heart failure is to classify it into either systolic or diastolic dysfunction.  Once this is done you can then prescribe a rational treatment.

What is diastolic dysfunction?

If cardiac myocytes are continually forced to work hard (for instance maintaining a high blood pressure), they slowly degenerate. Then one by one (like failing light-bulbs in a big electric sign) they die. Inflexible collagen, and amyloid replaces each dead myocyte. Because the remaining myocytes still contract normally the ejection fraction is unaltered, but the stiff heart can no longer distend to increase its stroke volume. Now the the heart can only increase its output by increasing its rate. Once left ventricular hypertrophy appears on an ECG, diastolic failure soon follows.

Consider diastolic dysfunction if the heart rate

is higher than the diastolic blood pressure.

 

To fill stiff ventricles the atria contract harder. They become distended and hypertrophy. On an ECG you see P-mitrale, or hear the atria struggle to contract as a 4th heart sound.

What is systolic dysfunction?

Myocardium weakened by ischaemia, infections, or toxins (such as alcohol) distends.  The heart becomes enlarged, with floppy flabby muscle. The tension exerted by the myocytes of an enlarged heart has to be proportionately greater to generate the same pressure. This sick ventricle does not contract efficiently, and the ejection fraction < 50%.  Sick ventricular myocytes have altered structure and function (cardiac remodelling). You can see this on the ECG as altered ST segments and T-waves, or hear it as a 3rd heart sound.

·   

 

Diastolic failure

= stiff  normal sized ventricles

Systolic failure

 = floppy dilated ventricles

Apex beat not displaced
Apex beat displaced = large heart
4th heart sound =daLUB DUB
3rd heart sound = LUB DUBBA
Needs a high preload
Needs a low after load
Resting pulse rate > diastolic BP
Flattened ST segment in lateral  V leads
Prominent Q-waves in V5 and V6
Septal Q waves in V1 but not in V5, V6

Echocardiograph is normal, but the patient is still poorly?

Studies show that echocardiography correlates poorly with functional capacity, It cannot be relied on to assess cardiac risk before non-cardiac surgery.  [Ann Int Med 125:433]

Some patients have symptoms of heart failure, but echocardiography reveals near normal systolic function with normal ejection fraction. In these cases there are two possibilities:

·  The most likely reason is that the patient has diastolic failure.

·  Something else is wrong eg. fluid overload, renal failure, severe lung disease.

5.  Valvular heart disease

Anaesthetists tremble merely at the thought of unrecognised aortic or mitral stenosis. The murmur of lethal mitral stenosis is so quiet you may not hear it; but there are symptoms.

(      Fast forward

Cardiac murmurs are serious if associated with breathlessness, clinical cardiomegaly, left ventricular hypertrophy on the ECG, angina, syncope or dizziness. 

             Order an echocardiogram if:

                        Murmur + dyspnoea on exercise            

                        Murmur + faints or dizziness

                        Murmur + cardiac failure

 

Syncope + murmur  = no anaesthetic ®  echocardiography®  cardiologist

 

In the elderly most murmurs are caused by benign degenerative disease. Providing they are asymptomatic they need no further special investigation before surgery.  They may need antibiotic prophylaxis if they are having dirty procedures. 

HAZARD: Spinal or epidural anaesthesia with valvular heart disease becomes hazardous if patients are unable to increase their cardiac output sufficiently to maintain their BP as the block causes their peripheral resistance to fall.

,             

·  An echocardiogram gives you much better information than a stethoscope. 

·  An extra sound in diastole is physiological in pregnancy, and in children and young people. In older people it is usually pathological, and is a useful sign of heart failure.

·  Don't draw conclusions from an isolated sign.  Look for further evidence of heart disease, such as hypertension, fluid overload, and dyspnoea.  

·  Normally the first heart and second heart sounds like "LUB  DUB".  It helps to silently sing it as you listen, "LUB DUB".  Go on - don’t just read it - try it!

·  A gallop rhythm will probably be either a third, or a fourth heart sound. 

·  A third heart sound occurs immediately after the 2nd sound. It arises from a floppy, dilated ventricle, and sounds like "LUB DUBBA" to cadence with "Wonthaggi".   It is a sign of systolic dysfunction and is always pathological. 

·  A fourth heart sound occurs just before the first sound. It is a sign of forced atrial contraction and sounds like "daLUB DUB" to cadence with "Adelaide". 

·  Occasionally you may even hear both as "Wooloomooloo". 

·  If you can’t tell if the extra sound comes before, or after, the first and second heart sound, then time the rhythm by feeling the carotid pulse with your thumb. 

·  A tachycardia where it is impossible to time the sounds is called a summation gallop.

About murmurs

·  Pansystolic murmur: VSD, mitral regurgitation, tricuspid regurgitation.

·  Ejection murmur: Aortic stenosis/sclerosis, pulmonary stenosis, ASD.

·  Diastolic murmurs (always pathological): mitral stenosis, aortic regurgitation.

·  Continuous murmur: patent ductus arteriosis.

·  Windmill murmur of air embolism: Sound like squelching in water filled gumboots.

How to grade murmurs

I           Barely audible

II          Easily heard

III         Intermediate

IV         Murmur + thrill

V          Loudest murmur requiring a stethoscope

IV         Murmur heard without a stethoscope

How to assess severity of VHD

Class

Effect

Mild disease

Usually asymptomatic except when exercising hard.

Severe disease

usually symptomatic with reduced exercise tolerance.

Critical disease

usually symptomatic with episodes of syncope.

Worrying symptoms include: breathlessness when walking, orthopnoea, collapse, nocturnal dyspnoea or cardiac enlargement.

Syncope + VHD = no anaesthetic -> echocardiography->cardiologist

What to do about symptomatic valvular heart disease

·  If not already evaluated by a cardiologist then refer the patient for assessment.

·  But first get a transthoracic echocardiography and in those with mitral valve disease also obtain a trans-oesophageal echo.

·  Consult the Antibiotic Guidelines to arrange suitable perioperative antibiotic cover

·  .

·   

·   

·   

Risk

Type of valve

Examples

Optimal INR

High

Ball in cage

Starr-Edwards

3.0 -  4.5

Medium

Single tilting disk

Bjork-Shiley

Medtronic - Hall

Omnicarbon

2.5 -  3.5

Low

Bi-leaflet tilting disk

St Jude Medical

Carbol Medics

Edwards Duromedics

2.5 -  3.5

What are the types of prosthetic valves?

Homograft valves

·  Derived from pig or calf with a life span of 10 - 20 years. 

·  After 6 weeks do not require ongoing anticoagulation.

Mechanical valves

·  Last 20 - 30 years before need to be replaced. 

·  Throw off emboli at a rate of 4% per year if not anticoagulated, 2% per year if treated with antiplatelet therapy, or 1% per year on warfarin. 

·  Valve thrombosis rate is 0.1 - 5.7% per year. 

·  Risk of embolism is higher if:

·  mitral valve replacement,

·  caged ball prosthesis,

·  more than one valve replaced,

·  during pregnancy,

·  patient in atrial fibrillation. 

How to manage patients with prosthetic heart valves

·  Prosthetic valves usually cause no problems. However there is a small chance they could be infected or are causing intravascular haemolysis.

What to check for

·  Bacterial endocarditis: fever (especially at night), joint and muscle pain (may imitate polymyalgia rheumatica), murmur, clubbing, splinter haemorrhages, splenomegaly, and a raised ESR or CRP. 

·  Intravascular haemolysis = haemoglobinuria, raised LDH, low haptoglobulins, increased reticulocyte count. 

·  Severe anaemia: valve ring is broken, or infection is causing para-valvular leakages.

·  Organise antibiotic prophylaxis in patients with mechanical heart valves.

Tilting disk prosthesis

·  Single tilting disks: Bjork-Shiley, Medtronic (Hall), and Omnicarbon.

·  Bi-leaflet tilting disks: St Jude medical (the most commonly used in Australia), Carbol Medica, and Edwards Duromedics.

·  Cease oral anticoagulants 5 clear days before surgery.  Use routine anticoagulation with dalteparin over the stay in hospital and recommence warfarin when the surgeon says the risk of haemorrhage has past.  The chance of emboli is small.

Older type caged ball prosthesis

·  Includes Starr-Edwards ball in a cage valve.

·  Cease oral anticoagulants 5 clear days before surgery — cover with dalteparin 2500 units s/c starting on day 3 before surgery.                   +   33

·  Use routine anticoagulation with dalteparin over the stay in hospital. 

·  Recommence warfarin when the risk of haemorrhage has past.

Mitral valve prosthesis causes extra problems

·  Mitral valve prostheses cause more embolic problems, particularly stroke. 

·  Cease warfarin 5 clear days before surgery — cover with dalteparin 2500 units s/c on day 3 before surgery. 

·  Use routine anticoagulation with dalteparin over the stay in hospital and recommence warfarin when the surgeon says the risk of haemorrhage has past.

Atrial fibrillation with mitral valve prosthesis (MVP)

·  AF + MVP + high risk of emboli, so patients are maintained at INR of 3 - 3.5. 

·  Cease warfarin, organise for their local doctor or hospital-in-th-home nurse to commence dalteparin 5000 units s/c daily starting the evening after warfarin stopped. 

·  Monitor anticoagulation with daily INR and aPTT.  Aim for INR 1.0 - 1.5. 

·  Maintain anticoagulation with dalteparin during stay in hospital

·  Recommence warfarin when the surgeon says its safe.

Antibiotic prophylaxis

Prophylaxis for endocarditis is unproven but accepted practice. Patients with diabetes and chronic renal disease are at greater risk of postop endocarditis. Use prophylaxis for known “dirty surgery”.  Any surgery involving the embryonic gut between the mouth and the anus including its offshoots: the biliary system, vagina, and genitourinary system, is dirty surgery. The mouth is the dirtiest place of all; any surgery in it (teeth extraction, tonsillectomy) or passing through it (bronchoscopy) needs antibiotic cover.

 

As a general rule, patients with mechanical valves need prophylaxis.

 

Prescribe prophylaxis for

Prosthetic mechanical heart valves

Acquired, but not congenital, valve disease

Hypertrophic cardiomyopathy.

Known mitral valve prolapse.

Prophylaxis is not needed for

Pacemakers

Previous rheumatic fever without surgical repair

Physiological or innocent murmurs

Echocardiography

Who needs echocardiography?

·  For major surgery patients with known symptomatic valvular heart disease need an echocardiogram done within the last 6 months.

·  Anyone with a murmur who can’t walk up a flight of stairs without becoming breathless, or has had attacks of “dizziness” (near syncope) or syncope.

And those with:

·  cardiac symptoms + murmur;

·  those with cardiac failure of unknown cause or type (systolic, diastolic, valves etc).

What are the limitations

·  Echocardiography is “technically difficult” in patients with BMI > 35.  You may not get a result, in which case order thallium scan for failure, or a thallium dipyridamole scan for those with IHD. 

·  The patient must be able to lie on their left side for at least 20 minutes.

·  Anaesthetists are most interested in ejection fractions ( EF). The cardiologists may not report EF unless you specifically ask them for it when ordering echocardiography.

·  Just because the transthoracic echocardiogram is OK doesn’t mean the heart is!  False negatives are common.  Severe diasotolic dysfunction can occur with a normal echo.

 

What is stress echocardiography?

·  Stress echocardiography looks for regional wall abnormalities caused by ischaemia either after graded exercise on a treadmill, or after inducing an increased cardiac output with dobutamine.  The abnormalities are matched with a simultaneous ECG trace.

·  Special requirements include no caffeine for 24 hours, to come off b-blockers, and drugs affecting adrenergic or dopamine receptors.

·  Not useful if patient has LBBB, or WPW – order thallium scan instead.

·  The patient is given special instructions about this stuff when the procedure is booked.

 

,  Fast facts

·  Transthoracic (TTE) or transoesophageal (TOE) echocardiography uses pulsed ultrasound at 1 – 7 Mhz to detect boundaries between tissues with different densities.

·  Used to delineate regional wall abnormalities: hypokinesia, akinesia, and dyskinesia – signs of myocardial ischaemia or death.

·  Regional and global abnormalities can be caused by changes in heart rate, preload, afterload, and drug, or exercise induced changes in contractility.

·  Anything lying toward the back of the thorax or within the heart are best detected by TOE: valve disease, vegetations, tumours, HOCUM, thoracic aneurysms.

·  Colour coded Doppler flow imaging is used to visualize flow patterns through the valves.

·  Stress echocardiography has an 85% sensitivity for IHD – much better than stress ECG - 65% sensitivity. Thallium scan has 90% sensitivity.

ECGs

Pragmatically, you should recognise an ECG in the same way as you recognise a dog.  Knowing the electrophysiology is nice, but you don’t need a DNA analysis to tell a bulldog from a poodle, and for most ECGs you don’t need to work them out from scratch. Carry a normal ECG to compare it with. You also need to know: blood pressure, body shape, COAD, and medication. (Be helpful; write this stuff on the ECG request slip.)

(       Fast forward to diagnosis

Work your way step by step through the data printed at the top of the ECG.

 

Useful stuff

·  Atrial fibrillation: then eliminate thyrotoxicosis and mitral valve disease

·  Heart blocks – look for ischaemia         = J point depression                                         

·  Left anterior hemiblock (LAHB): look for anterior ischaemia.

·  Left ventricular hypertrophy – look for hypertension.

P-waves

·  Normally precede QRS complex.

·  If dissociated from QRS = one of the heart blocks.

·  If absent: AF, sinoatrial block, AV nodal rhythm.

·  If peaked consider pulmonary hypertension.

·  Wide m-shaped  = stiff left ventricle ie. diastolic dysfunction, or mitral valve disease

·  Short PR interval = accessory pathway eg. WPW syndrome, or LGL syndrome

Q-waves

·  Normally Q -waves should be found in I, aVL, aVF, V5 and V6.

·  Normally there should be a little Q-wave in V6 = a good sign of a healthy heart.

·  Any Q-wave in V2, V3 or V4 is pathological

·  Q-waves are pathological if both of the following are present

·  width >= 40 msec  (one small square);

·  height >+ 30% of the following R-wave.


ST-segments

·  ST segment should be isoelectric (flat). Bad news if elevated or depressed.

·  J-point ST-depression (>0.5 mm) = serious ischaemia

·  Persisting ST-elevation in all leads indicates a ventricular aneurysm, or pericarditis;

·  Sloping T-waves

·  Reverse tick – digitalis effect

·  Normal tick – ischaemia

T-waves

·  abnormal if inverted in II, III, V3 to V6.

·  inverted = eliminate ischaemia.

·  peaked = hyperkalaemia.

·  flattened = ? hypokalaemia.

·  elevated = unless having acute ischaemia, consider ventricular aneurysm  

·  T-wave symmetrical in chest leads suggests sick myocardium.

Right axis deviation

·  R-axis on the top of the ECG should be less than +90°.  If >+110° consider right ventricular hypertrophy (pulmonary hypertension or outflow obstruction), left posterior henmiblock, anterolateral MI, thin adults, severe lung disease.

·  Rightward axis is > +80° -consider pulmonary hypertension.

Left axis deviation

R-axis on the top of the ECG should be in range of –30 to +90°. If less than –30° consider left anterior hemiblock, inferior myocardial infarction, emphysema, hyperkalaemia, WPW, ostium primum ASD.  Leftward axis deviation is <-20° - consider LAHB.

Additional stuff

·  Don’t be fooled by a normal ECG.  Up to 40% of patients with angiographic evidence of severe coronary artery disease have a normal ECGs.

·  Check for Q-waves.  Pathological Q-waves suggest previous infarction.

·  It is easiest to see rhythm abnormalities and P-waves in lead II.

·  Arrhythmias are easy to recognise because the various waves don't repeat themselves in nice neat regular patterns.

·  Worry about ischaemia, heart blocks, Wolff-Parkinson White and its analogues.

·  T- wave inversion in anterior leads always needs sorting out before surgery.

·  It is usually impossible, to diagnose either myocardial infarction or left ventricular hypertrophy in patients with a left bundle branch block (or with WPW syndrome).

·  Left ventricular hypertrophy? – eliminate aortic stenosis.

·  P-mitrale – then eliminate mitral stenosis.

·  AF + breathlessness – eliminate mitral stenosis.

·  ST-segment depression or T-wave inversion — consider ischaemia;

·  Asymmetrical T-waves indicate healthy myocardium; symmetrically formed T-waves suggest ischaemia; or some electrolyte abnormality.

·  Left ventricular hypertrophy + age >65 suggests heart muscle is damaged;

·  Left anterior hemiblock indicates left anterior descending disease. Look for QRS normal width, left axis deviation less than – 20°C, and positive R-waves in II, III, aVF.

·  Unless symptomatic then minor conduction disturbances eg. LAHB, RBBB or first degree atrioventricular blocks don’t need further work up. 

·  With complete left bundle branch block (LBBB) - exclude ischaemia as cause. Bundle branch block with dyspnoea, or worse syncope, need preoperative investigation.

 

RBBB + LAD = LAHB + RBBB

·   

·  b      Little gem

·  AF developing after surgery frequently indicates a pulmonary embolis.

Respiratory disease

(      Fast forward to diagnosis

Stand patient up. Ask them to take a deep breath in, and then with their mouth wide open get them to do a forced maximal expiration.  If they wheeze markedly or cough then they have airway disease. If the wheeze all the way through their forced expiration they may have asthma. If they crackle at the end then consider alveolar oedema. If they can only make a little puff, then consider restrictive lung disease.

What are the troublesome diseases

1.         Acute respiratory infections.                               +          68

2.         Chronic obstructive pulmonary disease.  +          70

3.         Asthma.                                                            +          72

4.         Restrictive lung disease.                         +          73

5.         Pulmonary hypertension.                                    +          74       

                        Cor pulmonale.

Pickwickian syndrome

6.         Sleep apnoea.                                                   +          75

How to pick the impending disaster

·  Patients with lung disease, who are breathless talking or while walking on the flat and who are to have major upper abdominal or thoracic surgery are going to cause big problems. They need preoperative lung function tests.

·  Pursed lip breathing will go into respiratory failure postoperatively.

·  Lung disease + peripheral oedema = disaster (may be cor pulmonale).

·  Raised JVPs or distended veins in their necks = disaster (may be cor pulmonale).

 

b        Little gems

·  The closer the surgical incision is to the diaphragm the more likely are postoperative pulmonary complications.

·  Clubbed fingers — a sign of inflammatory lung disease. 

 

About routine CXR                                                   +   14

Routine chest X-rays are a waste of time and money in:                                      

·  young asthmatics (unless you suspect they have a pneumothorax).

·  asymptomatic never-smokers under the age of 65.

What to do about smoking

· 

·  To benefit wound healing or lung function smokers need to quit at least 8 - 12 weeks before surgery. The benefits are huge! There is a 50% reduction in wound infection and poor healing in hip replacement surgery. In right-sided colon surgery smokers a six fold more likely to get anastomotic breakdown.

·  Patients sust cease smoking in three months before surgery where wound healing is a problem eg. breast reduction, abdominoplasty, operations below the knee, perineal surgery, and plastic procedures. 

·  Many patients won’t or can’t stop, but record that you have advised they do so.

·  There is some evidence (Level 3) that people who abruptly stop smoking in the week before surgery have a higher incidence of postoperative respiratory problems.  

·  But on the day of surgery even a few hours of not smoking reduces carbon monoxide levels and improves blood flow through the microcirculation.


1.  Acute respiratory infections

Surprisingly there are almost no studies about the risk of anaesthesia in patients with viral upper respiratory tract infections.  Like walking across a freeway while wearing a blind-fold anecdotal evidence indicates it is hazardous.

(      Fast forward

·  Patients with an active respiratory tract infection, either upper or lower, usually get pneumonia if they have a general, (or even a regional) anaesthetic, because surgery depresses the immune system.

·  Postpone asthmatics with a recent exacerbation for 3 weeks.

·  Postpone anyone with an respiratory acute infection for at least 2 weeks after it has resolved.

b    Little gem

The

The bronchial tree remains hypersensitive for up to 2- 8 weeks after a viral URTI.  URTIs may cause bronchospasm or laryngospasm during or after the anaesthetic — especially in younger patients. 

What to do about respiratory tract infections

Bacterial infections

·  Infected sputum precludes elective anaesthesia, because a postop chest infection (or pneumonia) is almost certain. 

·  Those with bronchiectasis continually cough up muck – little can be done about this.

·  TB – think of it. Calcified nodes or nodules on CXR.   Occurs with HIV/AIDS.  Be alert for persistent cough, weight loss, and night sweats.  Treated TB? - notify theatre.

Viral infections

·  After a viral URTI postpone elective surgery for at least 2 and preferably 3 weeks. because the bronchial tree remains hyper-reactive for this time. This makes patients wheezy postop causing them to cough. Treat as for asthma. Consider adding nedocromil to quieten down the IgE receptors on the mast cells in their lung.

·  A wheeze or cough persisting for  4 weeks or more after an URTI has resolved may indicate a viral-induced adult onset asthma, ongoing mycoplasma infection, or even more seriously, viral myocarditis.

About the "flu"

Occasionally a young adult has had “the flu” recently (especially in spring or autumn) and is still feeling crook with persistent cough, wheeze and continuing breathlessness on climbing stairs. Influenza, caused by influenza and para-influenza viruses, is a debilitating and occasionally a killing disease.  But not every URTI is influenza. Several strains of both Coxsackie A and B virus cause a flu-like illness progressing to myocarditis.  About 5% of symptomatic Coxsackie virus infections induce heart disease — usually with dilated cardiomyopathy or atrial fibrillation.  If this escapes diagnosis then there is a high risk of arrhythmias or even a cardiac arrest on induction of anaesthesia.

Middle ear infections

· 

· 

·  Treat middle ear infections and sinusitis before elective anaesthesia. 

·  Patients with obstruction to drainage of their sinuses get severe postoperative headaches, because nitrous oxide diffuses 34 times faster into the sinuses than nitrogen diffuses out.  It only takes a few minutes for the pressure to build up.

Children

Kids with snotty noses

Once children attend kindergarten most have continually runny noses.  For short procedures (<10 minutes), such as myringotomies where intubation is not needed then there is no increased infection rate provided the child is not febrile.  But there a 5 fold increased risk of laryngospasm (with the inherent risk of hyoxaemia) and chest infection in children who have had an URTI with cough and fever in the past 2 weeks if the anaesthetic requires intubation, or where the procedure is >10 minute.  In these cases wait 4 weeks for elective surgery, and in those with asthma wait 6 weeks.

Sometimes it seems impossible to find a suitable interval so you may need to compromise.

When to avoid major surgery in kids

·  Don’t send a sick kid for surgery.

·  If you can’t work out whether the child is sick - ask its mother.

·  Don’t even think of anaesthesia if the child is running a fever;

·  If the child is wheezy with a chest infection or temperature - don’t submit to anaesthesia;

·  If in doubt ask the anaesthetist.i.wheeze: anaesthesia;

·   

2. Chronic lung disease

(      Fast forward

·  Able to lie flat?  If not then may have premature airway closing: obesity or cardiac failure.

·  Peak flow >150 L/min for GA lasting <60 min.  Otherwise >250 L/min

·  Peak flows <250 L/min — refer to LMO for bronchodilator therapy

·  Need formal respiratory function tests if peak flow rate is < 200 ml/sec for major surgery or <150 ml/sec for minor surgery

·  Optimise therapy:

·  COAD = bronchodilator + tiotropium.

·  Asthma= bronchodilator + inhaled steroid

and then:

·  consult a respiratory physician unless formally assessed in the past 18 months;

·  consult the physiotherapists.  They may need a month or more to improve things.  This includes patients with morbid obesity, life style limiting asthma, or COPD.

·  Wheeze on forced expiration?  Start on salmeterol therapy 2 weeks before surgery and order salbutamol 5 mg in nebulizer 2 hours before anaesthetic. 

·  Coloured sputum?  Order sputum M & C, start on roxithromycin 300 mg daily x 5.

·  Patients with infected sputum are unsuitable for elctive anaesthesia;

·  Anaesthesia is rarely a problem in stable asthmatics, because the volatile anaesthetic agents are superb bronchodilators.

·  Ankle oedema + respiratory disease: get an echocardiogram to quantify or eliminate pulmonary hypertension.

The wheezy chest

·  Asthma — cardiac failure in the elderly is often misdiagnosed, and unfortunately then treated as asthma.  Asthma almost never presents for the first time postoperatively.  Think of aspiration, anaphylaxis and cardiac failure.

· 

·  Pulmonary oedema — usually respiratory rate >20, not febrile, can’t lay flat;

·  Pneumonia — usually have a respiratory rate >20, febrile, but able to lay flat;.

·  Anaphylaxis — you may never find the trigger.  Look for rash, mottled skin, mucosal swelling, wheeze, tachycardia, and hypotension.  Patients often feel jittery.

·   

·  Aspiration — after surgery aspiration of tiny amounts are common but often not suspected.  If large volumes aspirated you may hear wheezes in the right lung;

· 

·  Cardiac failure — left ventricular failure presents with a characteristic crackling wheeze and breathlessness on minimal exertion — frequently tachypnoeic, always orthopnoeic.

·  Chronic bronchitis — normal respiratory rate, but lots of rattles that you can feel with your hand;

·  Bronchiectasis — normal respiratory rate, but rattles that you can localize with your hand;

·  Bronchopleural fistula or lung abscess;

· 

· 

·  Inhaled irritants: cigarettes, and marijuana - patients wheeze when they laugh.

·   

Spirometry

Spirometry is only useful in operations involving upper abdomen, diaphragm or thorax which are more likely to cause postoperative respiratory complications than surgery elsewhere.

For surgery sited elsewhere no single respiratory function test consistently predicts problems, and the risk is almost independent of the anaesthetic technique used.  Of patients with perfectly normal lungs about 6% will have respiratory complications after any operation.  Epidural anaesthesia, and patient controlled analgesia (PCA) enable patients with FEV1 as low as 2200 ml to undergo most surgery.

Order respiratory function tests if the patient has respiratory disease limiting their ability to walk from room to room.  Respiratory complications are almost certain if their FEV1/FVC ratio is less than 65%, and the FVC is less than 70% of predicted.

Preoperative blood gases

How useful are preoperative arterial blood gases?

Not very!  You can get most information from a pulse oximeter and the electrolyte results.

1. Determine their PO2

 

.

 

Use the oximeter readings to give you a rough idea.

 

% Hb saturation 

(Pulse oximeter

At pH 7.40

P02  mmHg

% Hb saturation 

(Pulse oximeter)

At pH 7.40

Pa02 mmHg

60

31

90

61   < danger level

70

37  < critical level

91

64

80

45

92

67

81

46

93

70

82

48

94

75

83

49

95

80

84

50

96

87

85

52

97

96

86

53

98

109

87

55

99

110

88

57

100

110

89

59

 

 

 

2. Now determine their pH

Unless the patient is acutely ill, or in metabolic disarray (highly unlikely in Pread clinic) then their pH will be about 7.4. This means a hydrogen ion concentration of 40 nanomol/L. 


3.  Now work out the PCO2

Calculate the PaCO2  from the Henderson equation.

pH

 

 

6.8

7.0

7.1

7.2

7.3

7.4

7.5

7.6

7.8

 

 

[H+]

nanomol/L

 

160

100

80

64

50

40

36

25

16

 

4. What about the other parameters

Base excess, and standard bicarbonate are merely mathematical calculations derived from three three variables ([H}, PaCO2 and HCO3). The variables adjust themselves to keep pH at normal levels in stable patients, but are of little help in acutely ill patients.

 

An example: A 60­ year old man puffs in to Pread Clinic with COAD and a SaO2  of 92% for assessment for an inguinal hernia repair.  His plasma bicarbonate level is 36 mmol/L

PH = 7.4   (Because this is his usual state, his acid base balance will becompensated).

SaO2 = 92% therefore PO2 is about 67 mmHg (breathing air).

Actual bicarbonate = 60 mmol/L

Calculate PCO2                PCO2   = 24 x 60/40 = 36 mmHg

 

Observation: His ankles are swollen, and he has cold blue hands.

Assessment: Suspect cor pulmonale. Not fit for GA – consider spinal or local field block.

b       Little gems

·  Normal PaO2 = 104 - age/4   ie.  PaO2  = 80 mmHg in an 80 year old.

·  If PaO2 + PaCO2 > 140 mmHg then patient is receiving supplemental oxygen.

·  If PaO2 < 100 and PaCO2 < 40 when breathing oxygen then the lungs are sick.

·  With respiratory acidosis for every 10 mmHg increase in PCO2 the bicarbonate increases by 1 mmol/L acutely, and by 4 mmol/L after 36 hours.

·  Metabolic alkalosis? Consider hypokalaemia, or recent massive blood transfusion

Who to refer to the physiotherapists

Patient is:                     

·  having difficulty walking or has other mobility problems.

·  uses a gait aid;

·  is very unsteady on their feet.

or

·  Patients who exhibit four or more of the following:

·  elevated WCC > 11 x 106

·  O2 saturation <92% on room air;

·  temp > 38°C;

·  CXR findings consistent with infection;

·  altered sputum with moist cough;

·  need IV antibiotics;

·  increasing shortness of breath;

·  diagnosed as having postoperative lung complication.

Physiotherapy techniques include

·  Deep breathing exercises and lung expansion manoeuvres;

·  incentive spirometry;

·  CPAP masks;

·  Humidification and avoiding dehydration

About PRATS

The following is adapted from Box Hill Hospital Physiotherapy Department information sheet (2002).  Physiotherapists are very useful allies.  But they only accept referrals for low risk PRATs if you discuss patients with them first.

PRAT = physiotherapy risk assessment tool

Item

Description

Score

out of

A

            Incision above the umbilicus

 

2

B

            Age > 65 years

 

1

C

            BMI > 25

 

1

D

            Documented pulmonary history:

                         current cough producing sputum

                         current smoker or Quit < 6 weeks ago

 

1

1

2

 

Total

 

8

Risk:                 Low 0 - 4                      Medium to high  5 - 8

3. Asthma

Asthma is a common. It has its own problems. Asthma involves a small amount of smooth muscle constriction but a large amount of mucosal inflammation and oedema. 

(      Fast forward

·  If PFR < 150 defer surgery until asthma is controlled.

·  Don’t order routine chest X-ray – it is unlikely to show anything.

·  Document the triggers: allergy, exercise, cold wind; and effects of NSAIDs or aspirin.

·  Optimize recent exacerbation of asthma before elective surgery.  Recent exacerbations are revealed by one or more of 3 events: the cough or wheeze wakes patients from their sleep, they require more bronchodilator than usual, and they have a wheezy cough. b2-agonists  (salbutamol or salmeterol) are best for asthma. (Iipratropium is best for COPD). 

·  Patients should take all their asthma medication on the day of surgery whether they are wheezing or not. Ask them to take their reliever (bronchodilator) 10 minutes before their preventer.

·  Asthmatics with PEFR <180 ml/min may profit from pulse steroid therapy before major surgery.  Liaise with LMO.  Use prednisilone 0.5 mg/Kg for 5 days. 

·  One hour before surgery give a premed of nebulised salbutamol 2.5 mg.

·  If the patient is taking more than 10 mg prednisilone supplement with hydrocortisone postoperatively.  Major surgery requires hydrocortisone 100 mg 12 hourly IV;

Other points:

·  Viral infections are a potent trigger of asthma. Postpone elective surgery for 3 – 4 weeks if the patient has an URTI or acute chest infection.

·  Asthma rarely causes problems for anaesthetists, because their volatile agents are such superb bronchodilators.

·  Rarely a patient is still taking theophylline (Nuelin®). Check the levels preop. Theophylline has a very low therapeutic margin. This means the toxic dose (>120 µmol/L) is perilously close to the therapeutic dose (plasma levels of 55-110 µmol/L).

·  Preoperative blood gases aren’t necessary in stable patients.

·  Unless you think they have a pneumothorax a chest X-ray is unlikely to reveal anything.

·  If the patient is wheezy postoperatively get a chest X-ray - they may have aspirated.

b   Little gem

Patients don’t ever get “asthma” for the first time postoperatively.  If they start to wheeze consider aspiration, anaphylaxis, acute pulmonary oedema. A recent central line might have caused a pneumothorax.

4. Restrictive lung disease

(      Fast forward

· 

·  Patients usually have intrinsic lung disease, occasionally deformed chest walls, or paralysed diaphragms.

·  They have high resting respiratory rates. Unless they also have airways disease, they do not wheeze.

·  Lung function tests are a help –especially CO diffusing capacity.

·  Consult the physiotherapists.

·  Often taking steroids - may need postoperative supplements.

·  These patients do much better if they are mobilized as soon as possible. Sitting around in bed they are prone to chest infections.

5.  Pulmonary hypertension

(       Fast forward

·  Look for untoward breathlessness on exertion. If the patient is short of breath on walking up the corridor, or cannot do a 50 metre walk while talking then their lung disease needs to be optimised for anaesthesia. 

·  Cor pulmonale is caused by chronic hypoxia -> sustained constriction of pulmonary vessels which eventually fibrose that way.  

·  The risks are postoperative cardiac failure, respiratory arrest and sudden death. 

·  It is difficult to identify mild cases preoperatively.

·  Investigate with transthoracic echocardiography, but do tell the cardiologists what you suspect because they need to estimate the pulmonary artery pressures, and assess right ventricular function.

·  Routine therapy = diuretics, anticoagulants, dihydropyridine calcium antagonist (good stuff), home oxygen therapy, and possibly low dose digoxin.

,       Fast facts

·  Pulmonary hypertension (PHT) is uncommon.

·  Normal pulmonary artery pressure is 22/8 (mean 14) mmHg.

·  Mild PHT = 30 – 50, moderate PHT = 50 – 80 and severe PHT > 80 mmHg.

·  Usually caused by underlying lung disease.

·  Primary PHT mostly affects young women, and is serious bad news – get help.

·  Secondary PHT caused by: chronic lung disease, left ventricular failure, valvular heart disease (MS and MR), previous pulmonary embolism, sleep apnoea, all connective tissue diseases (esp. scleroderma), portal hypertension, HIV, and some others. 

·   

b Little gem

·  Respiratory disease + cold hands  -> check for pulmonary hypertension.

·  Pulmonary hypertension + ankle oedema = cor pulmonale

·  Patient with PHT get into trouble if their pulmonary vascular pressures rise even a wee little bit. So expect problems after total hip and knee surgery (they get fat or trash emboli). 

·   


Cor pulmonale

Cor pulmonale occurs when pulmonary hypertension causes right ventricular failure. The onset of overt right ventricular failure is bad bad news. The prognosis is miserable. Mean survival is about 3 years.  These patients are a serious anaesthetic risk, and an even worse postoperative risk. In the first few days postoperatively, they are apt collapse with untreatable acute heart failure and die.

(      Fast forward

Preoperatively

·  Before major surgery arrange postoperative admission to ICU or HDU.

·  Echocardiography and formal lung function tests. Look for pulmonary hypertension.

·  Consult the respiratory physicians.  They have useful new drugs including bosentan (endothelin receptor blocker) and sildenafil (phosphoediesterase inhibitor).

·  Treat oedema with diuretics. Start gently though, thiazide -> frusemide and then ease in spironolactone. Be careful because they are highly prone to hypotension.

·  Stop all NSAIDs - if necessary substitute paracetamol

·  Digoxin may help although toxicity is a problem, while ß-blockers are not indicated in isolated right ventricular failure.

·  Avoid general anaesthesia if possible.

Postoperatively

·  Benzodiazepines or opioids are prone to cause a respiratory or cardiac arrest.

·  Even the slightest acidaemia or hypoxaemia increases pulmonary vascular resistance precipitating acute right heat failure. This failure is diabolically difficult to treat.

·  Give unrelenting supplemental oxygen for 3 - 4 days after major surgery. 

·  If they have a history of right heart failure or if their serum bicarbonate is >34 mmol/L, use nasal oxygen prongs at 2 L/min.  Avoid using high oxygen concentrations (>28%) because the patient’s respiratory drive may depend on mild hypoxaemia rather than a rising PaCO2.

·  Measure urine output 2 hourly.  If the urine output <0.5 ml/Kg/hour seek advice. A falling urine output is a sign of a stressed patient, as are cold hands.

·  Use regional blocks for analgesia.

About home oxygen

If the patient needs oxygen at home it is better to:

·  avoid major surgery;

·  use regional anaesthesia where possible;

·  be prepared for postoperative pulmonary complications;

·  undertake earnest discussions with the anaesthetist to plan postoperative care.

How to recognise cor pulmonale

· 

·   

·  Blue bloated faces - often described in textbooks, but rarely encountered in practice.

·  Usually oedematous lower limbs.

·  Untoward breathlessness with minor exertion – useful warning sign.

·  A loud P2 in the second intercostal space a few centimetres left of the sternum. You may even feel the impulse tap against your finger.  .

·  A raised bicarbonate (>36 mmol/L) on their serum electrolytes.

·  ECG may show right heart strain and cor pulmonale - looked for one or more of: right axis deviation, peaked P-waves in lead II, tall R-waves in V1, and perhaps inverted T-waves in lead aVF and III.  

·  A raised bicarbonate + raised JVP +/- ankle oedema = impending disaster

Pickwickian syndrome

Rare. Also called alveolar hypoventilation syndrome.

Typically occurs in morbidly obese males with obstructive sleep apnoea, periodic respiration, daytime sleepiness, hypoxia, hypercapnoea, polycythaemia, and right ventricular failure (cor pulmonale).  They have so much trouble simply moving their chest up and down to breathe that they develop chronic hypoventilation with ­ PCO2 and consequently a ¯ PO2.  Chronic low PaO2 causes pulmonary vasoconstriction ® pulm HT.  This is invariably exacerbated by sleep apnoea.

Preoperatively

·  Weight loss is useful before major surgery, but almost always impracticable.

·  Organise ICU support postoperatively.  Refer the patient to the ICU team early.

·  If the patient has raised plasma bicarbonate (> 34 mmol/L) on their electrolytes then organize baseline blood gases.  Take two sets. One on 28% oxygen and one on air. 

Postoperatively

These patients are really really sensitive to opioids and sedative drugs. They just stop breathing. On the ward they need continuous pulse oximetry.

6.  Sleep apnoea

True sleep apnoea is unhelpfully defined as "the occurrence of 30 or more periods of complete cessation of airflow for 10 seconds or longer over a 7 hour period of nocturnal sleep. It is easier to ask their partner whether they stop breathing or snore. Look for early morning sleepiness, and headache when waking.

(      Fast forward

·  Patients with sleep apnoea are far more likely to suffer micro-aspiration postoperatively and then get pneumonia.

·  Postoperatively opioids may cause your patient to stop breathing and die.

Preoperative management

·  With severe untreated OSA refer to respiratory physician before major surgery. 

Postoperative

·  Insidious respiratory obstruction may occur in recovery room or they stop breathing in the ward when receiving an opioid either systemically or into the epidural space. 

CPAP machines

·  Patient with their own CPAP machines should bring them to hospital with them. 

·  The hospital’s electronic engineers may need to check the machines before admission,

,         Fast facts

·  Sleep apnoea is either obstructive sleep apnoea (OSA), or central sleep apnoea (CSA.   

·  Sleep apnoea is probably the most under appreciated disease of this decade.  Evidence is accumulating to show a high correlation between sleep apnoea and: hypertension, type II diabetes, dementia, ischaemic heart disease, cardiac failure, nocturnal epilepsy, stroke and even bedwetting.  

·  Night after night episodic apnoeic periods cause transient hypoxia. The brain suffers. The hypothalamus panics and turns on a stress response +++.  Plasma noradrenaline and adrenaline levels rocket up to cause hypertension, arrhythmias, and elevated blood glucose.  Hour after hour, night after night, year by year repeated episodes of cerebral hypoxia insidiously kills brain cells, and to a lesser extent cardiac myocytes.

·   

`      Physiological foundations

Patients with sleep apnoea who receive opioids for pain relief sometimes simply stop breathing, often in the early hours of the morning when the ward is dark and “nice and quiet”.  It happens this way. These patients already have abnormal respiratory drives and opioids (even given ino the epidural space) will turn down the volume control on their CO2 receptors even further.  But their hypoxia receptors have yet to recover from their anaesthetic.  Now there is nothing left to drive their breathing. Propped up on pillows, sedated slightly with morphine, and drowsy from a rising PCO2 heir head lolls forward quietly obstructing their upper airway. A few feeble gasps and it is all over. The nurse finds them dead an hour later.

Central sleep apnoea syndrome  (CSAS)

·  Lose central respiratory drive when asleep and then stop breathing. 

·  Especially vulnerable to opioid induced respiratory depression.

·  Obstructive sleep apnoea (OSA)

·  Snoring is common especially in males, the elderly and the obese. 

·  Eighty percent of those with OSA have daytime sleepiness. 

·  Hypertension is common. 

·  Polycythaemia indicates chronic nocturnal hypoxia and pulmonary hypertension.  i.polycythaemia: sleep apnoea;

Obstructive sleep apnoea (OSA)

Typically:

·  Older patient, male, and obese.

·  Patient snores, or stops breathing while asleep — ask their partner.

·  Restless sleep, thrashing about and abruptly wakening choking and panicking.

·  Day time sleepiness especially in the morning.

·  Morning headache and blurred vision — a sign of mild cerebral oedema caused by hypoxia.

Breathing

Every other obligation in your life (at least temporarily) is optional - except breathing. You won’t live long without adequate oxygen supply to your tissues. Neither can your patients. Postoperative hypoxia is common, often subtle, and causes permanent damage. 

There are four causes of hypoxia: low cardiac output (stagnant hypoxia), bad lungs (hypoxic hypoxia), not enough haemoglobin (anaemic hypoxia) and failure to release oxygen to the cells (metabolic hypoxia).

Oxygen is cheap. Nursing homes are expensive

About pulse oximetry

Just because the pulse oximeter reads 96%, this does not exclude hypoxia. Red cells suffering from storage lesion in transfused blood do not release oxygen to the tissues. Alkalosis has a similar effect.  Anaemic patients may be hypoxic) yet the pulse oximeter will show the occasional passing red cell is fully saturated with oxygen. 

,       Fast facts

·  Elderly people’s ventilatory response to hypoxia is only 25% that of a young adult, so they do not “breathe-up” as their oxygen saturation drop below 90%. 

·  After major trauma, and following major joint replacements lots of tissue debris (trash emboli) end up in the lungs. 

·  Following joint replacements air elderly people (when breathing air) have intermittent dips in oxygen saturation particularly during sleep. For a week or more after surgery their oxygen saturations often decrease intermittently below 85% (PO2 = 50 mmHg). 

·  Such hypoxaemia is unacceptable, and an avoidable cause of brain damage. Hypoxia is the usual reason “Granny was never the same after her hip replacement”. .

How to get the most out of oxygen therapy

·  Sit your patient up, because the lungs’ bases are better perfused and better aerated than their apices and so it follows: never tip your patients head down.  Even healthy people go blue for the same reason. 

·  If you have to increase their right atrial filling pressure to improve their blood pressure, then lift their legs on to pillows. About lung function tests

·  DCLO = diffusion capacity of carbon monoxide asses the area of the lungs available for gas exchange. Lung surface area is lost in emphysema.

·  FEV1 = forced expiratory volume in one second. This tests whether the airways are properly patent. This test is usually performed before and after bronchodilation.

·  PEFR = peak flow rate. This is a poor man’s FEV1 – OK but not nearly as good.

 

 

Who needs postoperative ventilation?

·  Preop risk factors are: pre-existing lung disease. abnormal pre-op blood gases. ineffective cough, obesity. Smokers, elderly debilitated or weak patients, anaemia, cardiac failure, neuromuscular disorders, patients going to the intensive care unit,

·  Operative risk factors include: upper abdominal surgery. thoracic surgery. especially where surgery involves the diaphragm. aspiration of gastric contents.  Patients who have an operation that breaches the diaphragm nearly always require postoperative support on a ventilator, even if it is only overnight.

· 


Renal disease

(      Fast forward

What to do before surgery

·  Review patiens’ therapy to uncover noxious drugs especially NSAIDs, or COX-2 inhibitors. These are dynamite if prescribed with diuretics, and if added to ACE inhibitors or ARBs it’s even worse (= Triple Whammy). All you need to now is stir in a little cephalosporin, or gentamicin and watch the kidney tubules swell and die.

·  Take your patients off any NSAID at least 4 days before their operation. If they are over the age of 70 then it is better not to re-introduce the NSAID after surgery.

 

Diuretic + NSAID + ACE inhibitor = Triple Whammy

Who to refer to a nephrologist

·  Stage 3 CKD need referral if: they have unexplained microscopic haematuria, unexplained Hb <110 gm/L, or abnormal potassium, calcium or phosphate levels, suspected systemic illness (SLE,PAN) or if the BP>150/90 despite being on 3 agents.

·  Stage 4 or 5  CKD.  It would help if your referral included the results of an FBE, U+Es, LFTS, calcium, phosphate, HbA1C (in diabetics), lipid profile, all the serum creatinines (with dates) you can locate and a renal ultrasound.

How to describe renal disease

In the past two years, the term renal impairment has been dropped, and the term renal failure has been redefined.  The new jargon is chronic kidney disease = CKD.

The old way

The Crockoft-Gault formula estimates creatinine clearance (glomerular filtration rates).

 

 

· 

·  Normal range = 80 - 120 ml/min

·  Renal impairment        = serum creatinine 0.12 - 0.19 mcg/L  (or est. CrCl  30-60 ml/min)

·  Renal failure               = serum creatinine > 20 mcg/L            (or est CrCl    <30 ml/min)

The new way

In 2005 the Australian Society of Nephrologists redefined the terms renal impairment and renal failure using the MDRD formula (Modified Diet for Renal Disease). This formula is more accurate, but needs a computer to do the sums. It gives a better estimate of glomerular filtration rate (eGFR) than the older Crockoft Gault Formula. The currretly accepted classification of chronic kidney disease (CKD) is based on the eGFR.

Classification of chronic kidney disease (CKD)

Stage

Description

eGFR*

Notes

1

Normal

>90

without evidence of kidney damage*

2

Mild impairment

60 – 90

without evidence of kidney damage*

3

Moderate impairment

30 – 59

 

4

Severe impairment

15 – 29

 

5

Established renal failure

<15

= “EFR” (new term)

*eGFR is standardized in ml/min/1.73m2.

 

The other evidence of chronic kidney damage may be one of the following:

·  Persistent microalbuminuria.

·  Persistent proteinuria.

·  Persistent haematuria after exclusion of other causes (eg. urological disease).

·  Structural abnormalities of kidneys on ultrasound eg. polycystic kidneys or reflux nephropathy.

·  Biopsy proven glomerular nephritis.

·  Patients found to have an eGFR of 60 - 90 ml/min/1.73 m2 without these markers should not be considered to have CKD and do not need further investigation unless their is additional reasons to do so.

Nasty effects of CKD

·  For every 10 ml/min decrease in glomerular filtration rate the risk of cerebrovascular disease and IHD is increased by 10% above the already existing prevalence; and this effect occurs continues an exponential fashion. Thus a patient with CKD and a eGFR of < 30 ml/min/1.73 m2 is almost certain to have coronary vascular disease.

·  Even mild CKD disturbs healing, delays the excretion of drugs, impairs blood clotting and causes other metabolic havoc. 

           

,      Fast facts

·  CKD is more common than diagnosed, and causes unending trouble. 

·  End-stage renal failure is uncommon.

·   The prevalence of CKD increases exponentially with age.

·  CKD CKD is more common in non-Caucasians.

·  Common causes of CKD are vascular disease, diabetes, and hypertension.

·  Many people suffer and some die because their Stage 4 CKD is not treated early

·  GFR needs to be reduced by >50% before creatinine rises above normal levels.

·  If creatinine clearance <50 ml/min the patient is at risk of postoperative renal failure.

·  Calculated estimated creatinine clearance is not always reliable.

·  CKD increases postoperative wound breakdown, infection and immune suppression.

·  The frail elderly with little muscle mass may have normal creatinines, but raised urea.

·  If necessary use an on-line MDRD calculator to help diagnose CKD. 

About proteinuria

·  Proteinuria + haematuria = diseased kidneys.

·  Damaged glomerulus ®  up to 2 gm/ 24 hours.

·  A dipstick is highly sensitive to albumin and less so to other proteins.

·  A trace of proteinuria is probably of no significance especially in women. 

·  Proteinuria of 100mg/L or more is serious, and worse if accompanied by haematuria. Order a urine micro and culture, a 24 hour urine collection for protein, albumin and creatinine clearance, and refer to the renal physicians for further investigation. 

·  Check for Bence-Jones protein (multiple myeloma) if  ³ 200 mg/L proteinuria.

Order a urine micro and culture

Nitrites in urine = infection, but only 50% of infections have nitrites in urine.

If nitrites present or culture is positive :

·  prescribe trimethoprim 300 mg daily for 5 (men) and 7 (women) days and refer them to their LMO. If trimethoprim is contraindicated then use cephalexin.

·  If the culture is negative:                     

If microhaemoglobinuria

·  and microscopy reveals > 75%  dysmorphic red cells then order 24 urinary protein excretion + renal ultrasound and refer to a renal physician.

·  If the microscopy reveals mixed red cell morphology and the patients is under 45 years then order 24 urinary protein excretion, and a renal ultrasound and refer them to a renal physician. however if the patient is > 45 years then order a renal ultrasound and refer them to a urological surgeon.

·  If the microscopy reveals > 80% isomorphic red cells then a renal ultrasound and refer them to a urological surgeon.

Intraoperatively

The Cochrane Data Base says that there is no evidence that any measures apart from maintining vascular volume ae useful to protect the kidney during surgery. Things that do NOT work are diuretics, dopamine, calcium channel blockers, or ACE inhibitors.

No urine?

In patient with a normal kidney:

·  Commonest cause of postoperative oliguria < 0.5 ml/Kg/hour is hypovolaemia.

·  Mortality of established postoperative renal failure is about 60%, but is easy to prevent.

·  If the patient has a preoperative eGFR < 50 ml/min/1.73m2 they need a catheter to monitor their postoperative urine output.

·  If their urine output falls below 1 ml/mn then trouble is brewing.

·  If the patient has a catheter then check its not obstructed.

·  If the patient doesn’t have a catheter then insert one.

·  Start supplemental oxygen.

·  NEVER GIVE FRUSEMIDE until you are ABSOLUTELY SURE  your patient is not hypovolaemic. In fact, never use frusemide until you have consulted a senior colleague.

 

Poor peripheral perfusion = poor renal perfusion

Ie. Cold hands = cold kidneys

 

·  If the patient has a tachycardia, or cold hands (and providing they are not wheezy or have creps in their bases) then assume they are volume deplete.  Give a quick bolus of 250 mls of Albuminex. Repeat at 30 minutes intervals until the pulse rate slows.

·  Control pain, because pain or hypovolaemia ® a noradrenergic stress response ® intrarenal arteriolar constriction ® ¯ urine output.

·  Central venous monitoring helps gauge intravenous fluid requirements.

How to detect depletion of intravascular volume (without a central line)

·  Tachycardia > 90 bpm

·  Poor peripheral perfusion. Squeeze a finger nail . Blood should flush back into the capillaries within 2 seconds. Cool hands in a warm ward.

·  Postural drop. Meaure the blood pressure while the patient is supine. Now sit them up and quickly measure it again. A postural drop in systolic BP should be less than 20 mmHg. More than this is an excellent sign of hypovolaemia.

·  Oliguria = urine output < 1 ml/Kg/hr.

·  Blood pressure does not necessarily fall in hypovolaemia, especially in young people, until the situation is absolutely desperate.

How to detect fluid overload (without a central line)

No single sign on its own confirms fluid overload. Look for evidence of interstital oedema, alveolar oedema, and high pulmonary vascular pressures.

·  Rising respiratory rate. Put your hand on the patient’s chest and count the respiratory rate. An early sign of fluid overload is a rising respiratory rate. Interstitial oedema stimulates pulmonary J-receptors. The normal respiratory rate is about 12 breaths per minute (not 20 as so often charted). If it riss to 16 then consider fluid overload.

·  Creps in the bases. Listen at the lung bases for creps (alveolar oedema). Pathological crep do not disappear with a deep breath.

·  Wheeze on forced expiration. Ask the patient to make a forced expiratory effort – you may hear a wheeze or even crackles if you listen with your ear ne\ar the patinet’s mouth.

·  4th heart sound. Listen for a 4th heart sound (da LUP DUB) indicating raised pulmonary vascular pressures. You will hear it best if you roll the patients toward their left side. 

·  Loud P2. If you are good wth a stethoscop you may hear a loud P2 (lub DUP). And, in thinner people, feel the pulmonary valve slam shut if you put your forefinger in the 2nd intercosatal space about 3 cm from the manubrium.

 

 

Diabetes mellitus

Diabetes on your thumbnail

Type I diabetes =  IDDM

              Type 2 diabetes = NIDDM

Autoimmune – can’t make insulin

Cells are insulin resistant

Sudden onset

Young and lean

Polyuria and polydipsia

Abdominal pain

Nausea and vomiting

Insidious and progressive

Often diagnosed when something else intervenes eg. UTI, AMI, skin infections.

> 40 years & overweight (truncal obesity)

Hyperlipidaemia

Hypertension

Needs:

  • Insulin
  • Fluids
  • Education

Needs:

  • Diet, exercise
  • Oral secretogogues: eg. Gliclazide
  • Oral sensitizers eg. Metformin
  • Sometimes insulin

Preop targets:                                BGL 3.5 – 8 mmol/L

HbA1C < 7%

BP <130/80

 

Postop target:                                 BGL <10 mmol/L

 

Preop:

Insulin: Never withhold insulin

Give half morning dose of insulin

Start 5% dextrose 6 – 10 /24

Preop:

Diet alone: no action needed

Oral drugs: withhold the night before and morning of procedure.

Insulin: Give half morning dose

Start: 5% Dextrose 6/24

Never withhold insulin

Withhold Metformin:

  • 1 day before, and 2 days after IV contrast scan.

·        36 hours before surgery involving vascular clamps or tourniquets.

Hypoglycaemia  BGL < 3.5 mmol/L

Never withhold insulin

Give 40 ml of 50% dextrose IV (Glucotol™)

Hypoglycaemia  BGL < 3.5 mmol/L

(Rarely occurs with secretogogues)

Give 40 ml of 50% dextrose IV (Glucotol™)

Endocrine registrar page: 3871                                   Mobile 0439 039 371

 

(      Fast forward

Surgical mortality rates are five times higher in diabetics than in aged matched comparable non-diabetics.  Diabetics die from especially from primary infection, anastomotic breakdown, pneumonia, pulmonary emboli, and adverse cardiac and cerebrovascular events. Good long term control of diabetes reduces these risks.

·  In Preadmission Clinic review the patient’s blood glucose diary.

·  Record likely problems:

·  autonomic neuropathy (blood pressure falls > 20 mmHg when they stand up)

·  reflux (with the dangers of aspiration pneumonia).

·  IHD

·  renal impairment.

·  peripheral vascular disease,

·  peripheral neuropathy (more likely to get nerve damage during surgery).

·  Notify the Endocrinology registrar of pending admission.

·  Check long-term control of blood sugars with HbA1C.

·  Also check spot glucose, and TSH if no measurements in past 6 months).

·  Optimal HbA1C levels are <6.5%.  For major elective surgery and HbA1C level >8% is a relative contraindication.  Consult surgeons and consider endocrinology referral.

·  All diabetics have an increased risk of ischaemic heart disease (often silent), hypertension, cardiac failure (which can be occult), renal impairment, vascular disease, and eye disease especially retinopathy.

·  If they have retinopathy - IHD is almost certain. Hunt for it!

·  Admit patients at  06.30 for morning surgery, or at 09.00 hrs for afternoon surgery.

·  When to check blood glucose

·  Check blood glucose concentrations on admission, in recovery room and then just before and again two hours after commencing or changing the insulin infusion.

·  How to manage bowel prep for diabetics                       +          104

Type I (insulin dependent) diabetes

· 

·  Patients admitted at 09.00 hrs can have a light breakfast + 1/3 of their normal morning insulin.

·  It is not unusual for the emotional stress of coming to hospital on the day of surgery to push diabetic’s blood glucose levels beyond 20 mmol/L.  There is no need to postpone surgery, just increase their insulin infusion by 30%.

·  Acute postoperative hyperglycaemia quickly injures vascular endothelium increasing the risk of thrombosis.

·  Hypoglycaemia is not usually a problem if you stick to the guidelines below.

Perioperative insulin therapy

·  DO

·  DODONOT use sliding scales to control glucose levels, because they allow alarming and endothelial damaging swings in blood glucose.

·  To inhibit ketosis, lipolysis and proteolysis diabetics need a baseline of 150 gm of

·  glucose every 24 hours.  This is the equivalent of 3 litres of 5% dextrose. Because this is a large volume you can use half the volume 10% dextrose into a big vein.

 

How to manage insulin 

·  Convert the sum of their daily normal insulin intake into 4 equal doses of regular insulin. Give insulin by infusion.  For instance if they are taking 20 units of protophane insulin in the morning and 16 units of regular insulin at night this converts to (20 +16) / 4 = 9 units of regular insulin given by 6 hourly infusion.  If you can’t infuse insulin then give it intramuscularly. Although painful, at least it will be absorbed. In the postoperative period subcutaneous is absorbed erratically.

·  Following surgery patients usually require about 25% more insulin.

·  Usually one unit of insulin decreases the blood glucose in a normal adult by 1.5 mmol/L. But after surgery (or trauma) one unit decreases the blood glucose by 1 mmol/L.

·  Give enough insulin to prevent hyperglycaemia, glycosuria, and ketosis, while avoiding hypoglycaemia. 

·  Monitor blood glucose levels 2 hours after receiving the insulin.

·  Ketones in the urine are a sign of insulin lack and not a sign of excess glucose.

·  When you check blood glucose levels, check potassium too.

 

b   Little gem

Diabetic retinopathy is a sure sign of coronary artery disease.  About 40% of diabetics with retinopathy who need laser therapy will die from heart disease within 4 years.

Type II (non-insulin dependent) diabetes

Diabetes type II - prevalence of 3 - 4%.  In Preadmission Clinic we pick-up many previously undiagnosed type 2 diabetics.

Mostly obese, mostly elderly. Often have other intercurrent diseases. If you find diabetes in a younger patient (< 50 years) and especially with a family history, always check for undiagnosed haemachromatosis. We find a couple of these tragedies every year.

(      Fast forward

·  Patients admitted at 09.00 hrs can have a light breakfast, but omit their oral hypoglycaemic drugs.

·  Open sores, urinary tract infections, or severe dental sepsis precludes joint replacement or vascular grafts.  For UTI take an MSU and start the patients on trimethoprim 300 mg daily for 5 days.

Oral hypoglycaemic therapy

·  For most surgery just oral hypoglycaemic drugs the night before surgery.

·  Admit patients at 06.30 for morning surgery, and no later than 09.00 hrs for afternoon surgery. 

·  If patient is to have radiocontrast dye, or a tourniquet is to be applied, or >500 ml blood loss is expected, then cease metformin 36 hours (one clear day) before surgery. This reduces the risk of lactic acidosis or renal damage.

·  Some type 2 diabetics require insulin to control hyperglycaemia after their surgery.

Metformin can be dangerous – when to stop it

·  Metformin prevents the liver from metabolising lactic acid.

· 

·  Stop metformin for 36 hours before and after administration of radiocontrast media.

·  Stop metformin 48 hours before major surgery, or where tourniquets or vascular clamps are to be used.

·  Lactic acidosis is fortunately rare, but if it occurs it is often fatal. Lactic acidosis can also occur when metformin accumulates (eg renal or liver impairment, old age heart failure).  Early symptoms include anorexia, nausea, vomiting, and abdominal or muscle cramps.

WHO definition 1998

Diabetes mellitus is a chronic disorder of carbohydrate, protein and fat metabolism caused by an absolute or relative insulin deficiency, fasting hyperglycaemia, glycosuria, and a striking tendency for atherosclerosis, microangiopathy, nephropathy and neuropathy.

           

b      Little gem

            Consider undiagnosed diabetes T2 if there are fungal skin infections in obese or elderly people, recurrent UTIs or sores that do not heal.  You may occasionally see thirst, polyuria, and nocturia, but rarely weight loss. 

`      Physiological foundations  “The diabetic story”

·  Diabetics main problem is tissue glycation. This means almost every cell outside the CNS are caramelized; their cell membranes are coated with toffee-like goo.

·  Glycated tissues do not heal well. Glycated fibroblasts don’t lay down collagen. Glycated white cells are too gummed up to detect (chemotaxis) chase and phagocytose bacteria. Glycaced complement proteins can’t trigger opsonization,

·  However the tissue that suffers the most are endothelial cells in the small vessels. Clots or plaques form on glycated endothelium increasing the risk of stroke, pulmonary embolism and adverse myocardial events. HbA1C reflects the amount of tissue glycation. It reveals glycaemic control over the past 60 days. An HbA1C > 8% reflects an unacceptable amount of “toffee tissue”.

·  Surgery damages tissue. In response the body mounts a chemical counter-attack to prepare the way for tissue repair.  Its weapons include circulating cytokines, membrane attack complexes (a MAC attack), complement, catecholamines, and a host of other inflammatory and immunological factors).

·  The combination of the chemical counter-attack and postoperative raised glucose concentrations accelerates damage to endothelial cells to warp-speed. There are catastrophic consequences of even brief periods of postoperative hyperglycaemia.

·  Although still common practice to operate on toffee patients, it is better for a patient to have elective surgery when their HbA1C is < 8%.

·  If postoperatively the blood glucose levels rise > 12 mmol/L in diabetics, then endothelial damage occurs within 20 minutes. This paves the way for postoperative MI, DVT and strokes, and increases the risk of these events about 15 fold.

·  Keep blood glucose levels < 10 mmol/L in the postoperative diabetic patient.

 

Diabetes is a disease

of the microvasculature – everywhere.

b     Little gem

             Use HbA1C% to estimate the average blood glucose concentration over the past 60 days;

HbA1C

Plasma glucose

HbA1C

Plasma glucose

5%

5.0 mmol/L

11%

15 mmol/L

6%

6.7

12%

16.7

7%

8.4

14%

20

8%

10

16%

23.3

11%

15

 

 

 

Other diseases

Alcoholism

(      Fast forward

·  Traditionally, patients are solemnly advised not to drink alcohol for 24 hours after surgery, because combined with anaesthetic agents alcohol affects conscious state and judgment.  Most alcoholics pay absolutely no attention to this advice.  Record your warning in the notes.

·  Patients drinking more than 60 gm/day (ie. 10 - 12 + standard drinks) then one month's abstinence before surgery reduces postoperative infections, promotes wound healing, decreases cardiac problems, and prevents exaggerated neurohormonal responses to anaesthesia and postoperative stress.

,       Fast facts

·   

·  After cardiac disease alcohol is the next major cause of major perioperative morbidity. 

·  Moderate drinking is defined as 3 drinks per day for men and 2 drinks for women. 

·  A practical definition of an alcoholic is someone whose life, or the life of their family and associates, is disrupted by their person’s drinking. 

·  Alcohol is a problem for 1:6 of Australian adults and 5% of men are overtly alcoholics. 

·  Elderly people can be quite heavy drinkers especially if they live alone.

Denial is a key feature of alcoholism

·  Diagnosis is difficult, and patients can be touchy about being questioned. In Australia using the American CAGE criteria for alcoholism only makes people defensive  - watch them fold their arms.  

·  It is easy: after inquiring about medication, and herbal remedies ask courteously. "When was the last time you had more than 5 (male) or 4 (female) drinks containing alcohol on one day?"  I have yet to find anyone offended by the question, and they usually reply honestly.  Less than 1 month 88% sensitivity. 3 - 12 months 81% sensitivity for predicting alcoholism.  If the answer is recently, then give a big grin and ask: "Do you drink a slab a day?” — you may be surprised by the reply. 

·  Check: their gait (a wide based stomp), occasionally you will encounter nystagmus, or peripheral neuropathy.  Younger men may have signs of oestrogenization: thin hairless arms, spider naevi, gynacomastia.  Usually heavy smokers.

·  Diagnostic hint: isolated increase in gamma GT enzymes with raised mean corpuscular volume in a “well” patient, suggests excessive alcohol consumption.  AST is twice as high as ALT. (In hepatitis the ALT > AST).

·  Cirrhosis is in the top 5 causes of death in Australia.  About 15 - 25% of patients with alcohol-induced cirrhosis also have HCV infection. 

Concurrent disease in alcoholics

·  Associated medical problems include: dilated alcoholic cardiomyopathy, dysrhythmias (especially AF), hypertension, cerebral atrophy with dementia, and liver involvement. 

·  Assess nutritional status.  Commence multivitamin therapy, especially thiamine, folic acid, vitamin C, and zinc. In skinny alcoholics organise protein supplements.

·  Nutritional problems (apart from thiamine deficiency -> Wernicke's/Korsakoff’s syndrome) include hypoalbuminaemia, and especially hypomagnesaemia.

·  Fatty liver.  Assay liver function, INR, and magnesium concentrations.

Alcoholic dementia (Wernicke-Korsachoff Syndrome)

·  Wernicke’s encephalopathy = confusion + ataxia + ophthalmoplegia secondary to thiamine deficiency, is said to contribute to 10% of dementia.  Tragedy if missed. Send your alcoholic patient home with a prescription for thiamine.

About postoperative alcohol withdrawal

·  It is the 3rd postoperative night. Our previously oriented man, who hasn’t slept for the past 2 nights now has a tachycardia, and a falling blood pressure. He is sweating profusely and screaming: “It’s the rats – bloody rats are coming out of the wall. They’re trying to bite me”.  He is trying to sweep them off his bed. He is terrified. His pupils are dilated and non-reactive. He’s got delirium tremens. About 2% of people with the DTs die from cardiac arrhythmias and respiratory failure. Fortunately, only 5% of alcoholics develop the DTs in hospital, but about half of alcoholics go through milder withdrawal: they get the trembles, feel anxious and can’t sleep. Once they start to feel nauseated or vomit, you have a problem. And once their sensorum becomes clouded you have a real problem.  They may go on to have seizures.

·  The easiest way to prevent postoperative alcohol withdrawal syndrome is don’t withdraw alcohol. Many hospitals seem to feel righteous about alcoholics, and virtuously get them off alcohol with an “Alcohol Withdrawal Protocol”.  In this case the alcoholic has to deal with the metabolic disturbances of surgery and the added physiological insults of the alcohol withdrawal, and the pharmacolocical insults of the program. Once they leave hospital the alcoholic will head straight for the pub anyway, so why bother trying to withdraw them? 

·  Alcoholism is a disease involving neuroreceptors.  There is altered cortical and subcortical GABA receptor activity, and an up-regulated NMDA response. You can’t fix that overnight - it takes weeks to months.

·  Although not encouraged at BHH the easy way out of the problem is to give the patient 2 beers with lunch and dinner. Or if they are not eating to slip 10 grams of alcohol (alcohol for infusion 10 ml) into each 8 hourly litre of whatever you are giving them. The hard way is to run them through the Alcohol Withdrawal Protocol.

Traps

·  Agitation, seizures or clouded conscious – also consider hypoglycaemia (depleted glycogen stores are common in fasting alcoholics) and hypoxia (as always).

·  Arrhythmias – consider hypomagnesaemia (common in alcoholics).

·  Just occasionally an alcoholic has “needed a few to steady their nerves” the night before surgery. Alcohol prevents the liver doing its neoglucogenesis thing, and without a carbohydrate load in the next 18 hours, they can suffer catastrophic hypoglycaemia. This usually presents like acute alcohol intoxication – the patient initially appears drunk, and later confused, abusive, then sleepy and finally fits and dies.

Allergies

Penicillin

About 80% of patients classified "allergic to penicillin" are wrongly labelled.  The true incidence is uncertain although many report urticarial rashes and angioedema.  1:20 of penicillin allergics have cross-sensitivity to cephalosporins.  Anaphylaxis in Australia is rare - reported incidence 3:10 000 people of which 10% die from it.  Amoxycillin causes rashes more commonly than penicillin.  

Latex allergy 

Latex allergy is a serious problem.  Follow BHH’s protocol. Usually confined to contact dermatitis type reactions, however more severe reactions such as urticaria, angioedema, conjunctivitis, asthma and anaphylaxis.  Cross-sensitivity with bananas, avocadoes and kiwi fruit.  Deceptive exposure in hospital occurs with plungers in syringes, caps on vials, injection ports on drip sets, anaesthetic bags.  High incidence in spinal bifida patients who have had repeated latex catheters. Alert the Director of Operating Theatre Services at least three days before planned surgery. 

Opioids

IgE mediated immune reactions are rare but not unknown especially with morphine. Morphine pethidine and tramadol can cause a red-flare along the veins, or occasionally localised hives.  Anaphylaxis has been reported.

Sulphonamides (“sulfas”)

With recent agreements about standards, the Americans insist we now spell sulphas as “sulfas”. Sulfa allergy is seen in older people who received antibacterial “sulpha drugs” years ago.  Sulfa based drugs frequently caused rash and fevers 7 to 10 days into treatment.  Reactions occur in 3 - 6 per cent of patients taking trimethoprim-sulphamethoxazole. Don't prescribe sulfa based drugs such as celecoxib (Celebrex®).

Radiocontrast media

·  Radiocontrast media causes allergic reactions in 5 - 8%

·  Anaphylactic reactions occur in 2 - 3 %.

How to prevent allergic reactions to radiocontrast

Allergic reactions to radiological contrast media can be modified by pre-treating susceptible people  with prednisilone, promethazine and ranitidine.  Consult the radiologists. Newer agents are less likely to be a problem than the older iodinated agents.

Muscle relaxants

·  Long acting non-depolarising muscle relaxants have cross-reactivity with compounds that contain tertiary and quaternary ammonium ions such as: antiseptics, cosmetics, some foods, and detergents.

·  Women account for more than 90% of anaphylactic reactions to muscle relaxants. 

·  Chief culprits are suxamethonium, alcuronium, and atracurium.

Colonophony (rosin) 

·  Colophony is the sticky stuff on most sticking plasters and surgical tapes.

·  Also found in cosmetics (lipsticks, nail varnish etc), toiletries (Pears™ clear soap, dental floss, sun-screens), household items (shoe and furniture polish), recreational (grips on tennis rackets and golf clubs), chewing gum and cardboard. 

·  Most common reaction is IgE mediated contact dermatitis.

Cerebrovascular disease

A stroke or TIA within the past 6 weeks increases the risk of further stroke after the operation 20 fold.  From 6 weeks to 3 months the risk of further stroke is about 8 fold, as is the risk of an adverse cardiac event. 

(      Fast forward

·  Defer

· 

·  elective surgery for at least 3 and arguably longer. 

·  Patients should be on a statin, beta-blocker, anti-platelet drug and ACE inhibitor.

·  Better not to stop aspirin – but check with your surgeon


Cyanosis

Central or peripheral cyanosis?  

Needs either daylight or daylight fluorescent tubes to diagnose it.  Incandescent light bulbs are useless.  In coloured people look at either their nail beds (peripheral), or their tongue (central).  If are in doubt then ask a nurse to stick her tongue out, and compare it with the patient’s tongue.

Peripheral cyanosis

·  Acrocyanosis + persistent painless symmetrical cyanosis of hands, and less commonly feet.  It is usually benign, but may be a sign of pulmonary hypertension or cardiac failure.

·  Pulmonary hypertension: peripheral cyanosis becoming central on exertion.  

·  Peripheral cyanosis: cold, connective tissue diseases (SLE, PAN, scleroderma), arterial disease (thoracic outlet syndrome, arteriosclerosis obliterans,), dysproteinaemia, myxoedema, primary pulmonary hypertension, and reflex sympathetic dystrophy following past trauma.

Central cyanosis

Hypoxia — it requires the presence of at least 30 gm/L of reduced haemoglobin before cyanosis becomes obvious under a special daylight fluorescent tube.  Anaemic patients who become cyanosed are desperately hypoxic.  Rarities causing central cyanosis include: methaemoglobinaemia, sulphaemoglobinaemia, methylene blue, and methaemalbuminaemia.

Disorders of speech

Hoarse voice

A croaky voice indicates pathology affecting the larynx.  Anaesthetists put their endotracheal tubes though the larynx, and prefer not to share this critically narrow aperture with inflammation, tumours, polyps, paralysed vocal cords, localized infections or enlarged thyroid or thymus glands. 

 

Find the cause before anaesthesia.  If the patient has only inspiratory stridor the lesion is usually extra-thoracic.  In contrast expiratory stridor alone suggest an intrathoracic lesion.  If the patient is breathless, then take them to the Emergency Department.

Dysarthria

·  Have difficult in co-ordinating their speech.

·  Upper motor, lower motor lesion, or extrapyramidal lesion

·  flat monotonous speech with Parkinsonism, 

·  explosive speech with chorea

·  slurred speech with cerebellar lesions, myaesthenia or motor neurone disease – quite common with brainstem ischaemia (check gag reflex because at risk of aspiration).

Dysphasia

·  Perceptive dysphasia – don’t understand what you are saying (temporal lobe) , or lost the ability to read (parietal-occipital area).

·  Expressive dysphasia - know what to say, but can’t get it out – (inferior posterior frontal lobe), or lost ability to write it down (posterior frontal lobe). 

·  Aphonia. Whispers, Local laryngeal disease or bilateral laryngeal nerve paralysis

Dizziness.

Probably the commonest complaint of the elderly is 'dizziness'.  Ignore it at the patient’s peril.  It frequently conceals a catastrophe waiting to happen.  Dizziness is not a medical term.  So unless your are quoting the patient don’t write 'dizziness' in the medical record.  Sort out what the patient means by 'dizziness', and then define accurately it as vertigo, or near syncope, or unsteadiness or whatever.

Dysphagia

Food gets stuck on the way down, while swallowing may be painful.  Causes include: myaesthenia gravis, scleroderma, autonomic neuropathy (usually diabetes), thyroid enlargement, brainstem ischaemia, dermatomyositis, Parkinson’s disease, muscular dystrophy, amyotrophic lateral sclerosis (= motor neurone disease), which make it difficult to swallow both solids and liquids.  In contrast cancer, and benign strictures make it difficult to swallow solids.

Dyspnoea

Dyspnoea

Dyspnoea D is a subjective feeling of being short of breath.  Some patients with COPD can puff away like a grampus, and not feel short of breath, while those with restrictive lung disease tend to feel short of breath even though they don’t appear that way. 

Preoperatively

Patients feel dyspnoeic whenever their work of breathing is increased because:

·  Airway is obstructed (asthma, bronchial oedema or inflammation, emphysema, tumour, inhaled object).

·  Lung tissue is stiffer than normal (interstitial or alveolar oedema, pneumonia, fibrosing alveolitis. or the lung is infiltrated with something — sarcoidosis, polyarteritis nodosa.

·  Pulmonary hypertension.

·  Cardiac physicians ask the question. “Do you get short of breath when you exercise?”, in contrast respiratory physicians earn their livelihood by asking. “Do you keep birds?”

Postoperatively

Abrupt onset of dyspnoea in the postoperative patient is caused by a pulmonary embolis. Full stop.  Gradual onset of dyspnoea then think of: aspiration, cardiac failure, chest infection, interstitial pulmonary oedema, pneumothorax, segmental lung collapse, systemic sepsis.

Epilepsy

(      Fast forward

 

· 

·  Unstable epilepsy of any sort precludes elective anaesthesia.  This includes seizures, or other symptoms, which despite therapy, have occurred within the last month. 

·  Patients must take all their antiepileptic medication as normal on the day of surgery. 

·  Refer to neurologists if any change in the epilepsy in the previous 3 months. 

·  Measure antiepileptic drug levels if epilepsy is unstable. don’t measure them in stable epileptics. 

·  Do order liver function tests, because these drugs often disturb liver function. 

Intercurrent infection

· 

·  Open sores, urinary tract infections, or dental sepsis preclude joint replacement or vascular grafts. 

·  With urinary infections take an MSU, and start trimethoprim 300 mg daily for 5 days (for men) and 7 days (for women).  

·  Recurrent UTIs in elderly - think diabetes.

·  To prevent postoperative chest infections and laryngospasm postpone anaesthesia for 3 weeks after an URTI, chest infection or presence of purulent sputum.

·  HIV/AIDs and hepatitis. Apart from usual suspects, consider if tattooed, or from overseas. All through Asia, Africa, and Eastern Europe hospitals, clinics and dentists are forced to reuse syringes and needles.  Sometimes their sterilization fails.

Goodness only knows (GOKs)

Every now and again a patient simply looks unwell and feels crook.  They complain about baffling non-specific symptoms such as tiredness, vague aches and pains, fatigue, lack of enjoyment in things they previously relished. They are unable to get going, sleep poorly, and occasionally lose weight, lose their appetite, and possibly their spouses.  They may run low grade fevers.  They seem “allergic” to everything including life itself.  Frustratingly, your examination may not reveal much, and you are left wondering whether the problem is all between their ears. This would be brave diagnosis indeed.  Well, there are a few diseases that they can make people’s lives miserable for years until finally someone twigs to the diagnosis, or they die where it may be discovered by the coroner.

Eliminate in the following order the likely suspects

·  Depression - Oh so common, and oh so overlooked.

· 

·  Diabetes. 

·  Addiction/overuse of alcohol, narcotics, marijuana, nicotine, benzodiazepines, but mostly alcohol.

·  Prescribed medication: especially cardiac drugs, anti-inflammatories, benzodiazepines, psychotrophics. Nonprescribed medication: all the herbal “weeds”.

·  Haemochromatosis - the most common inherited metabolic disease.

·  Thyroid disease - the scourge of older women. Ask about feeling the cold.

·  Hyperparathyroidism - abdominal groans (colic), psychiatric moans (depression, fatigue), fragile bones, and renal stones.

·  Asympromatic

·  urinary tract infections in elderly. A common reason for feeling “unwell”.

· 

·  Sub acute bacterial endocarditis (SBE). Yet another lethal reason to feel “unwell”.

·  Anaemia: especially pernicious anaemia in elderly men. Can cause dementia - a preventable tragedy.

·  Chronic fatigue syndrome is a very real disease (? post viral).

Then consider the fatal deceivers

·  HIV/AIDS. 

·  Renal failure — sneaks up slowly.

·  Connective tissue disorders: polymyalgia rheumatica, SLE, rheumatoid arthritis, amyloid, polyarteritis nodosa – check the ESR

·  Multiple sclerosis, motor neurone disease, Guillaine-Barre and its mononeuropathic variants,

·  Malignancies: lymphomas, multiple myeloma, lung, kidneys, caecum colon, or ovaries.

·  Parkinson’s disease.

·  Subacute infections: infectious mononucleosis, TB, chronic hepatitis (especially chronic HCV or HBV), and yes it is still around — syphilis. Don’t forget malaria, parasites and the zoonoses. Long term hangovers from Barmah virus, Ross River fever, and dengue take months and months to resolve.

Haematology

Haemochromatosis

·  Haemochromatosis is haemosiderosis that makes them sick. “The Curse of the Caucasians”. = rusty patients. Common and often missed diagnosis.

·  Screen all adult onset diabetics for iron-overload.  Do Fe++ studies.

·  Haemochromatosis serum iron >300 µg/dL, transferrin saturation >50%. Gene assay is diagnostic.  Test first-degree relatives. Treat with phlebotomy 5 - 8 times per year.

Look for

·  Rusty patients. Vague aches and pains. 

·  Myalgia occurs in 45% of cases, and arthropathy in 64%.

·  Early onset of osteoarthritis, chondrocalcinosis, and pseudogout. 

·  Stiffness and arthralgia in second and third metacarpals. 

Complications

·  Hepatic: increased activity of liver enzymes, fibrosis, cirrhosis.

·  Endocrine: diabetes, hypogonadism

·  Cardiac: myopathy, arrhythmias

·  General: skin pigmentation, lethargy and malaise.

·  Susceptibility to infection especially E.coli. 

·  Untreated, 14% get hepatocellular carcinoma.

Pernicious anaemia

·  Don’t miss this one! 

·  B12 deficiency ® anaemia. 

·  Pale lemon yellow skin, anaemia, a really preventable cause of dementia. 

·  M = F.  Common (1:200>65 yrs) especially in elderly with chronic atrophic gastritis (often on proton pump inhibitors) with failure intrinsic factor production. 

·  Autoimmune (90%), atrophic gastritis (10%).  In 40% of patients an auto-antibody is sticking to intrinsic factor too.  Patients with autoimmune atrophic gastritis are at high risk of gastric carcinoma    need routine gastroscopy every 3 years.  

·  If you miss the diagnosis of pernicious anaemia your patient gets dementia.

Thalassaemia

Thallassaemia minor is not a problem and needs no further works up.

Thallassaemia major is a big big problem and needs expert help from a haemotologist.

Sickle cell disease

This group of haemoglobinopathies is not common in Australia, but common in North Africa, parts of the Middle East and India.  Homozygote adults know they have it, but some of the heterozygotes may be unaware. Think of it because hypoxiaemia, even quite trivial hypoxaemia can precipitate a vaso-occlusive sickle cell crisis causing strokes, blindness, renal failure etc.  You will need help from a haematologist with SCD.

 

Liver disease

Who needs preoperative liver function tests?

·  Everyone over the age of 50 years who is having a general anaesthetic and is taking medication that may affect the liver (which means most drugs).

·  Everyneover the age of 70 years having major surgery.

Why?

·  If a patient gets jaundiced, or their liver enzymes rise postoperatively, it is comforting to know if their liver was normal preoperatively.

·  About 15% of the Australian population abuse alcohol. Excessive dinking is rarely admitted at preoperative assessment.  Every day people throw hepatotoxins at their liver, a normally robust organ, however during, and following major surgery, the liver’s reserves may be stretched to its limits by all sorts of insults: drugs (especially volatile agents and metformin), probably respiratory alkalosis (during IPPV), hypoxaemia (exacerbated by opioids), gram negative sepsis. 

·  During general anaesthetics the arterial blood supply to liver drops by > 50%.

When to worry

·  Some asymptomatic patients have abnormal liver function tests on routine preoperative screening. 

·  Although many drugs, and commonly the statins cause abnormal liver function if the levels of ALT are more than twice normal levels or GGT, ALP are more than three times normal levels, then order: ferritin, transferring, viral serology, serum copper, ceruloplasmin, autoantibodies, and a liver ultrasound, postpone elective anaesthesia and refer them to the hepatitis clinic.

 What are the minimum requirements for anaesthesia?

·  Avoid elective anaesthesia in patients with signs of liver failure.  The postoperative prognosis is awful.  If you must operate then ensure that the patient’s blood will clot.  Patients with symptomatic cirrhosis undergoing abdominal surgery have > 50% mortality.  Biliary surgery is particularly risky.

·  Alcoholic liver damage is common, but if asymptomatic is unlikely to cause a problem.

·  As normal clotting as possible.  Measure INR, aPTT and also a whole blood clotting time.

·  If you need to give a transfusion then use as fresh blood as you can find, and none of the 28 day old ammonia loaded stuff.

Pugh's (Child’s) surgical risk in cirrhotics

Score

I

2

3

Ascites

None

moderate

severe

Encephalopathy

None

1-2

 >2

Bilirubin mg/L

15

15-20

 >20

Prothrombin time

1-4

4-6

 >6

 

Good risk          5% mortality                  5-6 points

Moderate risk    10-20% mortality           7-9 points

Poor risk           >50% mortality >10 points

 

Following major surgery, mortality in patients with liver disease is quoted at 20-35%, but in those with severe (whatever that means) cirrhosis have an overall mortality >50%. 

 

Cirrhosis + major surgery plus

Mortality

     Respiratory failure

100%

     Cardiac failure

90%

     Renal failure

75%

     Liver failure

66%

Practical physiology about liver disease

·  Ascites = very serious liver disease.

·  Use spironolactone (not frusemide) to treat oedema and ascites.

·  Hypomagnesaemia is often overlooked.

·  Hyponatraemia can be a problem because after surgery patients can either go into renal failure or develop cerebral oedema. Both have bad outcomes in cirrhotics.

·  Cirrhotics may have huge spider naevi in pleura. Up to 40% of cardiac output can be shunted through these dilated vessels from left to right causing severe hypoxia.

·  Cardiac output at rest usually between 8 - 10L/min, but may go as high as 16 L/min.

·  Respond poorly to catecholamines because they have depleted adrenergic nerve endings and receptors in ventricles.

·  Wounds heal poorly, concurrent infection is cammon, and exacerbated by poor nutrition.

Drugs in patients with cirrhosis

Cirrhotics need reduced doses of many drugs because they have:           

·  Damaged blood brain barriers which are more permeable to stuff. 

·  Fewer neurotransmitters making their brain more sensitive to many drugs.

     Ascites and oedema causes an increased volume of distribution.

     Greatly reduced muscle mass decreasing the volume of distribution of drugs.

     Decreased transport proteins in blood.

     Decreased hepatic blood flow.

     Impaired Phase I drug metabolising enzymes in their liver.

How to interpret LFTs

·

Malnutrition

Malnutrition is common, and its consequences mind-blowingly under-estimated. It contributes to, and is a key predictor of poor wound healing, increased susceptibility to infection, poor response to antibiotics, and prolongs hospital stay. Ask a dietician to assess patients ASAP.

Classification

·  Two classes: fat and thin malnutrition.

·  Two groups:

o   protein calorie group

o   vitamin mineral deficiency group: folate, Vitamins B1, B12, D2, zinc, magnesium and iron.

How to identify malnutrition

Nutritional status is jeopardized if there are two or more of the following:

·  Low body weight or BMI < 19

·  Unintentional weight loss > 3 Kg in past 6 months

·  Low albumin (< 35 gm/L)

·  Low iron stores

·  Expected to be nil orally for > 3 days

·  The motivationless: severe dementia, and severe depression.

b     Little gems

·  Elderly people who cannot rise from a sitting in chair without either pushing up with their arms or someone’s assistance, probably have protein malnutrition.

·  Postop infection and wound dehiscience likely if unintentional weight loss >3 Kg over the past six months. 

·  All patients going for major surgery profit from two weeks of preoperative low dose vitamin and mineral supplement eg. Centrum®. However, make sure there are no added herbs (plant toxins eg. garlic, fever few, evening primrose oil etc) in the tablets.

Causes of malnutrition

·  Chronic disease including cancer, chronic inflammation and infection — responds poorly to feeding.

·  Starvation — responds dramatically to feeding.

,       Fast facts

·  Malnutrition affects up to 40% of surgical patients in all age groups. 

·  Marasmus (thin malnutrition) is is common in the elderly.

·  Fat people may be muscle wasted on the inside esepcailly if they have been dieting. 

·  Frailty in an older patient is a sign of “low nutrient intake” (= starvation), but particularly low protein intake.  Many elderly people subsist on a diet of tea, toast, and jam.

·  Few poorly nourished patients are recognised before their operation, and of those who are identified even fewer receive appropriate management. 

·  Malnutrition impairs organ function and recovery from illness.  

·  Properly feeding your patient before surgery reduces morbidity.  

·  About 20% of elderly patients who fracture their hip are severely malnourished, and in this group the mortality is about 20%.

·  If you can improve your patient's nutritional status before they undergo major surgery they are 8 times less likely to have postoperative wound breakdown or infection

·  One study demonstrated a 72% complication rate and 23% mortality rate in malnourished patients, compared with 29% complication rate and 4% mortality rate in the nourished.

·  The inflammatory response with wound exudates, fibrin clot formation in days 1 – 5 after surgery needs: vitamin C, and E, selenium and arginine.

·  Fibroblast proliferation, collagen synthesis and formation of new blood vessels need vitamins C, B1, and C; and zinc.

·  The tensile strength of wounds depends on collagen contraction and cross-linking. It can take 6 weeks to years for a wound to reach maximum strength.  It requires vitamins A, and C; and zinc, cobalt, and magnesium.

Body mass index

Body mass index(BMI)   =           weight Kg

                                                (height metres)2

 

BMI overestimates body fat in people who are muscular and underestimates body fat in the elderly, who have lost muscle mass.

 

Status

BMI

Starving

<17

Normal 

19 – 25

Overweight

25 – 30

Obese

30 – 35

Very obese

35 – 40

Morbidly obese

40 – 55

Super-morbidly obese 

>55

Thin malnutrition

·  With malnutrition the body mass index (BMI) is usually, but not always, <19 Kg/m2. 

·  If a patient is 25% below normal body weight, or has a body mass index of <17.5 they are likely to report: apathy, fatigue, and a loss of will to recover.

Things to check

·  Normal triceps skinfold thickness >10 mm in males and >13 mm in females.

·  Loss of muscle mass, weakness.  Check biceps muscle radius — reflects protein stores. Malnutrition if  < 23 cm in males and < 22 cm in females.

·  Oedema — consider low serum proteins.

·  Skin changes — flaky skin suggests zinc deficiency. 

·  Spiral subcutaneous hairs, bruising and gum disease suggests vitamin C deficiency.

·  Osteoporosis and recurrent infections especially urinary tract infections.

Subjective global assessment score (SGA score)

Class A.

Well nourished.

No weight loss.

Triceps skinfold >1 cm.  BMI 20 – 25

Class B.

Mild malnourished, or suspected malnutrition.

5 – 10% weight loss.

Triceps skinfold <2 cm.  BMI 18 – 20 

Class C.

Severely malnourished.  >10% weight loss,

no subcutaneous fat on triceps,

>10% weight loss BMI <17.

b     Little gem

A Cochrane Study in 2005 showed that elderly people recovering from acute illness were much less likely to develop pressure ulcers when given two daily supplement drinks.  Eastern Health has available the following: high protein fluids, high protein/energy supplements, vitamin and mineral supplements, and specific wound healing nutritional supplements.

Fat malnutrition

Just because your patient is fat does not mean that their nutritional status is OK. Protein and vitamin malnutrition is often severe in fat elderly women.

 

b     Little gem

            Patients with malnutrition aren’t strong enough to rise out of a chair without pushing with their their arms. The have neither stamina nor strength.

What to order

Laboratory markers do not help much with the diagnosis of malnutrition. However:

·  U+Es: Severe malnutrition may be associated with hyponatraemia Na+ < 134 mmol/L

·  Iron study: Low iron stores without evidence of bleeding.

·  There are other fancy tests – not readily available: eg. immunological skin challenge tests (The Four Scratch Test = streptokinase/dornase + mumps/measles + Mantoux + monilia). If they react to all = excellent, but 2 or less = surgery will fall apart.

 

            Consider malnutrition if the lymphocyte count <1.2 x 10 9/L.

`      Physiological foundations

·  Tissues need aminoacids to synthesize protein. Therefore, a diet containing inadequate protein delays wound healing.

·  Fibroblasts need ample arginine to proliferate and lay down collagen.

·  Carbohydrates and fats provide energy for the immune system. If these are removed from the diet, the immune system is the first to suffer, and infection soon follows.

·  B Group vitamins are needed for protein, fat and carbohydrate metabolism. 

·  Vitamin A is needed for epithelial cells to grow and divide, and to allow healthy granulation tissue to form.

·  Vitamin C is needed in copious amounts for wound healing and collagen synthesis.  This 17th Century scourge, scurvy, remains surprisingly common in the elderly.  When there is enough vitamin C in the diet, (at least 60 – 100 mg a day) preferably from food (not tablets), then wounds generally heal well.

·  Zinc promotes wound healing. By increasing epithelialization and cellular proliferation.      

·  Malnutrition alone does not cause decreased albumin concentrations until the patient is near starved to death.  However with the malnutrition of chronic disease the albumin concentrations fall below 30 gm/L, and will not recover to normal concentration until the disease process resolves.  Giving these patients albumin infusions makes absolutely no difference to their surgical prognosis. It is the underlying disease that stops the liver constructing this big complex protein.

·   A serum albumin <35 gm/L for minor surgery or <39 gm/L for major surgery such as hip replacement accurately predicts problems with healing and infection. 

·   

·  If the serum albumin concentration is <30 gm/L there is a 50% increase in infection rates compared to those where the serum albumin concentration >30 gm/L. 

·  If the albumin is <21 gm/L the patient is at extreme risk of complications of malnutrition, and it would be prudent to defer elective surgery.

·  If the serum albumin is <18 gm/L before major surgery, it may decrease below the critical concentration of about 12 gm/L following surgery. Should postoperative infection intervene, low pressure pulmonary oedema is inevitable.

Obesity

Check

·  MET score – walk them 50 metres and note dyspnoea or fatigue.

·  BMI                                                    +          93

·  Airway: access is made difficult by fat face, big breasts, short necks, limited cervical spine movement, high anterior larynx, and restricted mouth opening.

·  Reflux; Most have gastric reflux ± hiatus hernia with risk of aspiration. Consider pantoprazole 2 hours before surgery + 0.3 M sodium citrate 30 ml just before induction.

·  Sleep apnoea?

·  Ankle oedema?                                   +          59 and 95

·  Diabetic?

·  Hypertensive?

·  Check for

·  intercurrent problems: cardiomyopathy, cardiac failure, IHD, dyslipidaemias, cor pulmonale, cerebrovascular disease, peripheral vascular disease, varicose veins, prior VTE; restrictive lung disease, Pickwickian syndrome, aspiration pneumonitis;  hypothyroidism, polycystic ovary disease; fatty liver; spinal disease (especially lumbar), osteoarthritis of hips and knees, chronic back pain, fungal skin infections.

Tests to order:

·  U+Es, FBE, LFTs

·  Bariatric surgeons need extra tests – follow unit’s policy

·  Preoperative respiratory function tests don't usefully predict postoperative problems.

What to look for

·  Polycythaemia suggesting severe sleep apnoea, or chronic hypoventilation.

·  Bicarbonate >34 m suggesting CO2 retention and Pickwickian syndrome

·  Can they lie flat?  Very obese people may panic and become hypotensive when they attempt to do so, but they need to lie flat on the operating table, with their head on pillows.

Extra stuff

·  If > 150 Kg need special bariatric precautions: reinforced beds, lifting machines, reinforced operating tables, trolleys. Notify nursing staff in OR and wards in advance.

·  Some prefer to sleep in a special chair – they may have to bring it with them. 

·  Weight reduction immediately before surgery does not reduce morbidity and mortality.

·  Give drugs according to ideal body weight, not their actual body weight.

IBW (Kg)          = height (cm) - 100 for men

                        = height (cm) - 105 for women

·  Major surgery in the obese?  Then discuss elective admission with ICU staff if:

·  BMI > 50 or

·  BMI > 40 with cardiac or respiratory disease. 

·  Chronic CO2 retention – Pickwickian Syndrome (look for a HCO3> 34)

·  Never give sedatives. Opioids may depress ventilation unduly.

·   

·  Obese patients are often depressed, and psychiatrists say some are commiting suicide with a knife and fork.

Pitting oedema

(      Fast forward

What to do

·  Pitting oedema < 1 cm + METs >2 -> proceed with minor surgery

·  Pitting oedema + METs < 3  + major surgery -> defer and refer to LMO

·  Pitting oedema + nocturia > 2 -> defer and refer to LMO

·  Pitting oedema + lower limb surgery -> defer and refer to LMO

·   

NSAID (or COX) + thiazide + ACE inhibitor (or sartan) -> Triple whammey

Kidneys turn white (low blood flow) with  stress eg. CCF or surgery.

,       Fast facts

·   

· 

·  Pitting ankle oedema indicates an extracellular fluid (saline) overload in excess of 5+ litres.  Indicates excessive vasodilation, ¯ renal blood flow and ­ ECF volume. Patients unable ­ cardiac output either during the anaesthetic, or for a few days after surgery.

·  Common drug causes: NSAIDs, inhibitors, calcium channel blockers. 

·  Myxoedema tends not to pit. 

·  Lymphoedema does not pit readily. 

·  Don’t take blood or insert drips into (lymph) oedematous limbs. The holes won’t seal, tissue fluid will drip out, and the patient will probably and rightfully sue you.

Rheumatoid arthritis

This multisystem autoimmune disease causes symmetrical chronic inflammation and destruction of cartilage and connective tissue in joints, muscles and organs. F3:M1 (usually 35 – 50 age group). 25% have cervical spine instability – a problem when moving or intubating RA patients. It is easy to damage their spinal cord or vertebral arteries.   

What to check

·  FBE, U+ES, LFTs, ESR, CXR

·  Those

· 

·  Those with moderte or swho need intubation need lateral cervical spine X-ray. 

·  If your suspect cervical spine pathology or there are signs of nerve compression, deformity, restricted movement or pain then organise an MRI of their cervical spine.

·  TMJ is affected so check they can open their mouths widely.

·  Cardiac rings are often involved causing valvular incompetence. Check for murmurs.

·  Severe rheumatoid sometimes comes with pericardial effusions.

·  Malnutrition is common risking postoperative infection and poor wound healing.

What to do

·  If the RA is flaring, with an ESR > 40 then consider deferring surgery – do not stop their methotrexate without consulting a rheumatologist.

·  Stop leflunomide and methotrexate for a week before surgery. 

·  They are sensitive to opioid respiratory depression. Start with smaller doses.

Syncope

Syncope = transient loss of consciousness. It is caused by a brief, self-limiting episode of global cerebral hypoperfusion. Causes: neurogenic (vasovagal or carotid sinus syncope), orthostatic (absolute or relative hypovolaemia), cardiac arrhythmias (tachy- or brady- cardias), structural heart disease, and cerebrovascular disease.  In the elderly syncope causes falls where the patient “wakes up on the floor”. Drugs are frequently the culprit especially: antihypertensives, diuretics, anxiolytics, antidepressants, and antiparkinsonian drugs.

(       Fast forward

·  Postpone elective anaesthesia.

·  Order 24 hour Holter monitor and refer to physicians for follow-up.

·  Get an ECG.

·  Check the blood pressure – supine, sitting, standing (and again after standing for 2 min). 

·  Listen for carotid bruits, check for faintness on extending neck (vertebral artery syndrome) or turning the head (carotid sinus). check gag reflex (basilar artery syndrome).

·  Ask about palpitations (arrhythmias), family history of sudden death (long QT syndrome), arm exercise (subclavian steal), with or after exercise (cardiac).

 

b     Little gem

If patients are confused after fainting, it is probably epilepsy, not syncope. 

Thyroid disease

Hypothyroidism

Myxoedema = ­ TSH and low T3 and T4.  Hypothyroidism = ­ TSH and normal T3 or T4.  Myxoedema is rare but subclinical hypothyroidism is common and often overlooked for years especially in postmenopausal women. They inevitably feel the cold, and lack energy.  Myxoedemic patients can die if subjected to major surgery.  Hypothyroid patient are at risk of postoperative hypothermia, CCF. Most have IHD. They heal poorly, and are prone to infection. With opioids they may become obtunded, hallucinate, and get respiratory depression.

What to check

May have delayed ankle jerks, scaly skin and so on, but don’t rely on it.

TSH is a screening test, but unless it is abnormal there is little point checking T4. 

 

Check TSH in the following groups:

·  Post menopausal women who feel the cold,

·  Age >60,

·  Previous thyroid surgery

·  Any autoimmune disease: rheumatoid arthritis, SLE, PAN, Wegner’s

·  Metabolic disorders: diabetes; Down’s syndrome; thallassaemia, lung and other cancer.

·  Medications: lithium, amiodarone (contains iodine), alpha inteferon therapy. 

Check thyroxine levels

·  If not done within past 6 months, check thyroxine levels in patients taking thyroxine.

What to do

·  Postpone surgery in myxoedemic patients until it is controlled. Thyroxine is like a Mack truck, it takes more than a week to get going, even when used parenterally, and once up to speed tends to hang around for weeks to a month or more.  Myoxoedema needs to be treated by an endocinologist.

·  Mildly hypothyroid patients can under go minor surgery, with little risk but it is better to control the problem first. Refer the patient back to their LMO.

Hyperthyroidism

·  Usually obvious: recent weight loss, resting tachycardia, heat intolerance wears summer clothing in mid winter, and if seriously hyperthyroid often have AF. 

·  Watch out for the skinny demented elderly patient with AF (thyroxoxic madness). These patients easily die under anaesthesia.

What to check

·  Check TSH – usually below normal levels.

·  Check for a fine tremor as they hold their arms out stretched and spread their fingers.

·  Postpone surgery because they often have cardiomyopathies and tend to get horrific ventricular and supraventricular tachycardias whenever they challenged with a whiff of a sympathetic stimulus.

Goitres

Check they are clinically and biochemically euthyroid.  If their face becomes congested when they lift their hands above their head (Pemberton’s sign) get an ultrasound of the thoracic inlet. Check for deviated trachea. Check competence of the laryngeal nerves by asking them to do imitate a mosquito “Eeeeeeeeee”.  Of course do TFTs and Ca++.


Women's Business

 

What to do about breastfeeding mothers

Inform the anaesthetist.  Milk can expressed into sterile bottles and kept deep frozen for up to 7 months.  For day surgery cases express and refrigerate one feed.  Express and discard the first feed after surgery and bottle feed the baby for this feed, and then resume normal breast feeding.  Many drugs, especially the fat soluble ones, enter breast milk.  Avoid benzodiazepines because concentrations are sufficient to sedate the baby.  Codeine, fentanyl, paracetamol and morphine are consider safe, and will not enter breast milk sufficiently to affect the baby.   .

What to do about pregnant women

Although patients answer it on their questionnaire, it is essential to confirm that there is absolutely no possibility of females being pregnant.  Anaesthesia in first trimester increases the risk of spontaneous abortion.  To avoid the risk of foetal abnormality avoid all drugs during organogenesis (between days 15 and 25).  If you are in any doubt about whether they are pregnant then check ßHCG.

How hyponatraemia can kill young women

Water overload from giving too much 5% dextrose can kill young women and children. In contrast to adult men, premenopausal women and children are at extremely high risk of cerebral oedema should their serum Na+ decrease to 130 mmol/L acutely.  It may kill. Those who survive get central pontine neurolysis and are doomed to the locked-in syndrome with life long paralysis being able to move only their eyes.

Oral contraceptives

·  Many younger women come to Preadmission Clinic still taking their OCP. 

· 

·  To reduce the risk of VTE the OCP needs to be stopped a month before surgery. 

·  To stop or not to stop?  A vexed and emotional issue with a high risk of litigation if things go wrong.  OCP probably do predispose to spontaneous thromboembolism.  The risk is increased by factor of 2.3 for most OCPs.  Third generation OCPs (gestrodene or degesterol) increase the risk by a factor of 4.2.  Most published evidence is inconclusive at best, but still it is widely quoted as proven fact in women's magazines. 

·  Progesterone OCP probably don’t increase the risk of perioperative VTE.

·  Manufacturers of OCP impractically suggest stop OCP 4 weeks before planned surgery, and to start again after the patient is fully mobile, and their wounds healed.  Usually this takes at least 6 weeks.  In these 10 weeks the patient may fall pregnant.  Some authorities suggest the risks associated with unwanted pregnancy are greater than risks of VTE.

·  Probably there is no need to stop OCP for minor surgery, or progesterone based OCP at all.  For major elective surgery discuss the options of postponing the procedure with woman and the surgical unit, and always always note content of these discussion, and the decisions made in medical record. 

·  If OCP is stopped warn the woman about the risks of becoming pregnant, and suggest alternative contraceptive techniques.  Patients have sued, and won, because they were not warned they may get pregnant if they came off the pill.  Write everything down!   Emphasize the importance of postoperative leg exercises, especially on emergence from anaesthesia, and in the first few postoperative hours.  Use LMWH, and graduated elastic compression stockings.

What to do about selective oestrogen receptor modulators (SERMs)

·  Tamoxifen and raloxifene are used for the treatment of oestrogen sensitive breast cancer, and more recently breast cancer prevention, and now the prevention and treatment of osteoporosis.  Both these drugs increase the risk of venous thromboembolism.  In patients using SERMs for breast cancer treatment, they should continue to take the drug.  For other indications it is best ceased 4 - 6 weeks before surgery, since there is little chance of short term problems.    

Is anaesthesia during pregnancy safe?

·  Delay surgery, if possible, until at least 14 weeks of gestation.

·  Mendlesson’s syndrome (fulminant aspiration syndrome) is a risk, so take precautions against aspiration.  Lower oesophageal tone is lost by about 6 weeks into pregnancy. 

·  Pregnant women are hypercoagulable, and at high risk of DVT.  Use elastic stockings and encourage leg exercises as soon as the woman emerges from anaesthesia. 

·   

·  Unlike warfarin, which is teratogenic, subcutaneous heparin does not cross the placenta, and has no apparent effect on the foetus. If using heparin prophylaxis preoperatively warn the woman about the possibility of premature labour.  If she develops any sign of cramping or increased Braxton-Hicks contractions to come to hospital immediately. 

What to tell women having epidurals or spinals

Caesarean section

Women coming for neuraxial anaesthesia (spinal or epidural) need a step-by-step explanation of the entire procedure. Record each step in the notes.

Back pain is common following Caesarean section, and frequently the block is blamed for this. This is a principal cause of litigation.  Many anaesthetists get a separate written consent for elective peidurals. Warn the woman of the possibility of back pain. Permanent nerve damage is fortunately rare, but transient sensory (and sometimes motor) neuropathies are common. Usually this is little more than a numb spot on their backside or leg that resolves after a day or two.

A failed epidural may mean that the anaesthetic has to be converted into a general anaesthetic. Epidurals rarely fail on the first occasion, but epidurals for subsequent deliveries become increasingly patchy, and after the 3rd or 4th may not be effective. The probable cause is scarring in the epidural space, where organised blood clot delays the spread of the local anaesthetic.

Other points

·  Women having Caesarean sections do not get a premed.

·  Soon after the block is placed patients often beome hypotensive. This is usually accompanied by nausea. This is treated by a low dose of ephedrine.

·  Oxygen is routinely given throughout the procedure.

·  The babe is usually out by the 7-minute mark, and it takes about an hour to sew up.

·  At BHH, one partner or support person can come into the theatre.

·  Some vague deep abdominal discomfort may occur because the block does not catch the afferents carried by the vagus nerve.

·  Less than 10% need a blood transfusion.

·  A urinary catheter is passed at the start of the procedure, but it is not left in.

·  DVT and PE are major risks – and the commonest cause of maternal death.


Anaesthetic Stuff

Airways and how to assess them

The ultimate responsibility of an anaesthetist is to get oxygen to the patient’s mitochondria.  Fail this duty and your patient dies.  A patent airway is the first step in this process. The Mallampati test identifies half those who will be difficult to intubate.  Ask the patient to fully open their mouths and stick their tongue out as far as possible.  Most problems occur with class 3 (only soft palate visible) and class 4 (soft palate not visible).

Other things that raise suspicion of difficult airways are. cervical spine disease, TMJ abnormalities, prominent teeth, underslung jaw (sometimes concealed behind beards), connective tissue disorders, young Type I diabetics, short necks, short fat women.

Pain

There are lotsof fancy definitions, but practically pain is what the patient says “hurts”. 

Type of pain

Description

Responds best to

Clinical

 

 

Somatic pain

Well localized, sharp, acute pain arising from skin, muscles, joints.

NSAIDs, paracetamol ± codeine, (or paracetamol + tramadol –> vomiting +++).

Visceral pain

Deep, diffuse, ill-localized arising from an organ.

Morphine, oxycodone.

Tramadol – yuk!

Pathological description

 

 

Neuropathic pain

Arises from injured nerves.

Tricyclics, gabapentin

Nocioceptive pain

Occurs where inflammation stimulates pain receptors

NSAIDs, steroids

Steps in management

1.      Cause of pain? – find it

2.      Assess the amount of pain

3.      Reassure and comfort your patient

4.      Effective and appropriate analgesia – give it

5.      Reassess

Cause of pain

·  Not all pain is due to surgery.

·  Don’t miss other calamities eg. MI, PE, pneumothorax. 

·  Pain occurring while the patient has an epidural running often means something surgical has happened. Back pain suggests epidural haematoma or infection.


How to assess amount of pain

Best.    Ask the patient and use the Wong Baker pain scale.

Good. Verbal scale: (5) Unbelievable. (4) Very severe, (3) severe, (2) not too bad, (1) OK (0) no pain

Poor.   The numeric pain scale 1 – 10 is often used. It makes the staff feel virtuous but confuses the elderly, is useless in the demented, and scares the innumerate.

 

How to treat acute pain

Give an intravenous dose of morphine until the pain goes away. Use a loading dose of 0.1 mg/Kg IV over 5 minutes and add 2 mg every 5 minutes until the pain goes away. (in frail people use half the dose).  Once pain is controlled then if possible add oral analgesic from the table above.

Why pain is harmful

Uncontrolled pain is harmful because it:

·  Causes restlessness, which increases oxygen consumption. This in turn, increases cardiac work, and can result in hypoxia.

·  Contributes to postoperative nausea and vomiting.

·  Increases the blood pressure, with the risk of precipitating cardiac ischaemia. 

·  Decreases hepatic and renal blood flow, delaying the metabolism and excretion of drugs, and promoting fluid retention.

·  Prevents the patient from taking deep breaths and coughing, especially following thoracic, or upper abdominal operations. This increases the risk of postoperative sputum retention and pneumonia.

·  Discourages patients from moving their legs, slowing blood flow causing venous stasis that predisposes to deep vein thrombi, and pulmonary embolism.

·  Increases postoperative stress response, with greatly increased cortisol secretion.  This delays wound healing, and predisposes to infection. Cortisol levels rise up to 10 fold.

·  Increases metabolic rate, protein breakdown, and the catabolic effects of injury.

·  Delays the return of normal bowel function. Slows liver arterial blood fow.

·  Demoralises patients, disrupts sleep, and causes misery and despair.

·  After caesarean section, a mother's pain may impair the bonding with her child.

Uncontrolled pain delays healing,

and increase the risk of infection.

 

The greatest physiological risk of untreated pain is to frail patients, those with heart or lung disease, and those undergoing major procedures such as aortic, abdominal, or major orthopaedic surgery, the very young, and the very old. 

Tips about morphine

·  Morphine is occasionally still called a DDA = “dangerous drug of addiction”. Morphine is safe. It is the best analgesic.

·  The worst it can do is slow breathing down and sedate your patient.

·  Give enough to relieve the pain, or until they become drowsy, or their respiratory rate drops to 10/minute. 

·  Traditionally (but without good reason) avoided in asthmatics. One trial at The Mayo used it in > 1750 asthmatics without a problem.

·  The average loading dose is about 0.1 – 0.2 mg/Kg IM four hourly as needed.  In young people start with the higher dose.

·  Intravenously give 2 –2.5 mg every 5 minutes.  Morphine causes motion sickness. 

·  Now this is important, very important indeed: morphine will not cause the blood pressure to fall unless the patient is hypovolaemic.

About measuring respiratory rate 

Although it is traditional to record the respiratory rate on the ward chart as 20/minute, the normal respiratory rate is 12 – 14 /min. CO2 retention causes problems when the respiratory rate is 8 or less. The best way to measure the respiratory rate is to put your hand on the patient’s chest or upper abdomen and count it with a sweep second hand.  After surgery a change in the respiratory rate is a powerful sign that something has happened. As fluid enters the interstitium in the lungs with systemic sepsis or fluid overload the respiratory rate will rise from say 12 to 18+ per minute. Yet you won’t hear creps until the fluid enters the alveoli. A good early sign of developing septicaemia or pulmonary oedema is a falling PCO2  (® acute respiratory alkalosis).

Vomiting

·  Granisitron is the probably the best antiemetic but it often causes headache.

·  Patients fear nausea and vomiting more than pain.

·  Women vomit  more than men.

·  Younger people vomit more than older people.

·  Gynaecological, laparoscopic and strabismus surgery is notorious

·  Opioids cause motion sickness, which responds to prochlorperazine.

·  Metoclopramide (Maxalon) is useless for opioid induced vomiting (motion sickness).

Apfel’s risk factors

·  Female                                               score    1

·  History of motion sickness                               1

·  Nonsmoker                                         1         

·  Given opioids                                      1

Apfel’s risk score

Risk factor

Chance of vomiting

0

10%

1

20%

2

40%

3

60%

4

80%

* Start with half an ampoule of Stemetil® ie. prochlorperazine 6.25 mg IM  - 6 hourly.

b     Little gems

·  It is easier to prevent nausea and vomiting, than to treat it.

·  Give prophylactic antiemetics in the operating theatre, control pain, do not move patients roughly, and sit them up as soon as possible.

·  Give oxygen.  A generous litre of Hartmann’s during the procedure seems helps a lot.

·  If one antiemetic hasn’t worked, then use one from another group.

·  Check what, if any, antiemetic the patient received during their anaesthetic and choose one from another group.

·  Nausea after a spinal or epidural anaesthetic warns of low blood pressure.

·  When the input for nausea or vomiting arises in the abdomen, or mediastinum via the vagus nerve then try metoclopramide, otherwise use prochlorperazine or danisetron.

·  If you are not sure what is causing the vomiting then use granisetron

·  Droperidol is certainly effective, but it in larger doses has unpleasant side effects, and since the FDA put a black-box warning on it in 2002, droperidol has fallen out of favour.

·  Droperidol, dexamethasone, and gransetron are equally effective in prophylaxis of postoperative nausea and vomiting. 

·  To be effective dexamethasone has to be given during the anaesethetic.

Veins

Keep your anaesthetist happy. They usually put drips in the patient’s left arm.  So don’t stick needles in the left cubital vein or they may leak when fluid is run in from below.

 

b     Little gem

·  In fat patients or patients with “no veins” wrap their left arm in a towel before they leave the ward to come to theatre.

·  Can’t find a big vein to cannulate?   Put a tiny needle in a small vein.  Apply a venous tourniquet above the site, and inject 30 - 40 ml of warm saline to blow-up little veins into big ones. Still can’t find a vein – submerge the hand in warm water or use a hair dryer.

·  Thrombophelebitis is a sin – a potent source of septicaemia. 

·  If in doubt then whip that drip out and replace it.

·  As a rule drips should be replaced every 36 hours.

·  Veins are valuable. They may be needed for future fistulae in patients with CKD  (eGFR < 20 ml/min/m2). Keep away from the veins around the wrist and cubital fossa. 

·  Old people get severe pain, sometimes for months, if you put drips in the back of their hands.  Find a vein on their forearm.

Why is emotional status important?

`      Physiological foundations

·  Perhaps

· 

· 

· 

·  Perhaps because we can’t measure our patient's emotional state, and record it on a nice scale as we would for blood glucose levels, we tend to overlook it.  

·  Listen with the ears of your heart. For many people their upcoming operation is one of the top three major emotionally stressful events in their lives. Emotionally unstable patients are likely to sue you back to the Stone Age you if anything goes wrong, and might just sue you for imagined injustices, errors or insults if everything goes right. 

·  There is an avalanche of data to show that emotional and physical stress changes the structure of your brain, and the neuro-physical-hormonal-cytokine responses affect the whole body — big time! 

·  Anxious, or frightened patients do not do well. 

·  There is iron-clad (Level 1) evidence that emotionally stressed people are at a higher risk of DVT, wound breakdown and perioperative adverse cardiac event.  Those with depression are four times more likely to die in the perioperative period when compared with a normal patient.

·  Demented patients are likely to become confused postoperatively causing distress to everyone. Unstable schizophrenics heal poorly, and get infected easily. These patients are much more likely to die too.  Careful planning and lots of empathy will keep you in bed at night.

Routine postoperative orders (RPAO)

Each surgical unit has its own criteria for postoperativeorders. Most problems occur within the first 4 hours of the patient returning to the ward.  Then things are usually stable until the 2nd day aor 2nd night.

Basic orders.

First 4 hours: BP, pulse, resps, conscious state, perfusion status, urine output and oximetery every 30 minutes.  Temperature 2 hrly. Report to medical staff if BP<100 or >160, pulse <60 or > 120, resps > 20, SaO2 < 95. Deterioration in conscious state.  Temp >37.8°. Stridor or difficulty with breathing.

Do no harm

  1. The confused restless or agitated patient is usually hypoxic, but the cause may be obscure.  Hypoxia and hypoglycaemia kill in minutes. Other causes: drug or alcohol withdrawal, drug toxicity, septicaemia.  Anaesthetic make patients sleepy, they do not cause confusion. Never sedate a confused patient until you have sought advice.  
  2. The blood pressure does not necessarily fall with bleeding.
  3. Always find the cause of a tachycardia.
  4. Find the cause of and treat postop hypertension – it is always signals problems.
  5. Noisy breathing is obstructed breathing, but not all obstructed breathing is noisy. Snoring = obstructed breathing.
  6. Opioids do not cause the blood pressure to fall in stable patients.
  7. Pain prevention is easy than pain relief.
  8. Cuddle crying children, and hold the hand of frightened adults.
  9. Only warm blood with an in-line blood warmer. Never put this living tissue in the microwave or hot water. Do not store blood in the ward refrigerator.
  10. When giving drugs to the elderly start, by giving half as much, twice as slowly.
  11. If you do not know the pharmacology of a drug, then do not give it. Look it up including drug interactions.
  12. If confused read rule #1.

Bowel Prep

To reduce the risk of faecal spill, and postop infection bowel prep surgeons prefer bowel prep before colorectal surgery  The pharmacy dispenses bowel prep without a script.

Bowel prep is absolutely essential for colonoscopy. Although attitudes are changing it is still used by most surgeons especially before right-sided colon surgery and with some gynaecological surgery.  Each surgeon has their own preference – so check first. 

Each brand gives a massive, but mercifully brief explosion of diarrhoea often with abdominal cramping.  So warn you patient not to stray to far from their lavatory.

Types and effects

Two types:

·  Golightly® requires the patient to drink 2 - 3 litres of fluid (a logistic problem for some patients but less likely to cause dehydration). 

·  Picoprep-3® is a small volume of highly osmotically active fluid, which when drunk, causes a disproportionate response at the other end and patients may easily lose enough fluid to cause serious hypovolaemia and compromise their already parlous renal function. 

·   

Elderly patients living alone can become hypotensive and collapse with bowel prep. They may not be found for several days. Admit the following patients to hospital for bowel prep the day before their procedure: the frail, the elderly living alone, and those with exercise limiting heart disease to receive this stuff under supervision.

What to do

Patients should not be alone when they take their prep because they may collapse from hypotension. Suggest to your patients that they drink electrolyte replacement, such as Lucozade® (contains glucose, and electrolytes). This will not affect their fasting status and has no effect on the contents of the lower bowel.

Bowel prep purges

Major surgery is a huge physiological stress. During and after surgery the heart, lungs and kidneys need to accelerate from cruise control into overdrive. To do this our patients, in every respect, need to be as fit as possible. Marathon runners prepare for days for their physiological stress.  Yet we have our elderly patients up all night on the toilet, possible with major electrolyte losses (particularly K+ and Mg++), reduced glycogen stores, dehydrated and already catabolic. Then we bring this exhausted, metabolically disarrayed, dehydrated, unfit, elderly patient to theatre and do major surgery on them – this strikes me as madness. Rehydrate and rest your patients before major bowel surgery.

For colonoscopy stop

·  7 days before stop:

·  fibre supplements (Metamucil and Fibrogel),

·  iron tablets (FeFol) because they leave rust marks on the bowel wall.

·  4 days before stop: Aspirin and NSAIDs because they cause bleeding. 

·  2 days before stop all fibre in diet.  Permitted foods include: eggs, pasta (without meat or veges), white bread, butter or margarine, potato (no skins). Do not eat: meat, fish, fruit, vegetables or cereals in any form.

Diabetics and bowel prep

Diabetics should maintain their normal medication. Replace their glucose load with Lucozade® which contains 30 grams of glucose in 250 ml of fluid. Diabetics need 180 gm of glucose (6 X 250 ml bottles spread evenly through the days they are fasting). They must monitor their blood glucose levels carefully.  On day of their procedure omit oral hypoglycaemics medications until after the test. Take half their morning insulin + 250 ml of Glucosade and come to by 9.00 am hospital for IV glucose drip.

Measurement

Plasma volume

Adult males = 45 mls/Kg of body weight

Adult females = 40 mls/Kg of body weight             

Blood volume (in ml/Kg of body weight)    

Body build

Muscular

Normal

Thin

Obese

Males

75

70

65

60

Females

70

65

60

55

Children

 

75

 

 

Neonates

 

80 - 85

 

 

Ideal body weight

            Men (Kg)          = height in cm – 100

            Women (Kg)     = height in cm  - 105

Surface area

            Body surface area = ((height + weight) –60) / 100

Arterial PO2

Arterial PO2 should be close to inspired PO2 – arterial PCO2. If it isn’t, then there is something wrong with the lungs eg. pneumonia, PE, pulmonary oedema COAD etc.

Inspired PO2 = 713 x % inspired oxygen/100

 

Age dependent PaO2  = Age/4 – 4



Generic Names vs Trade names

 

Trade name

Generic name

Ablecet

amphotericin

Accolate

zafirlukast

Accupril

Quinapril

Accuretic

Hydrochlorthiazide+ quinapril

 

Acenorm

Captopril

Acimax

omeprazole

Aclin

sulindac

Actilax

lactulose

Actonel

risedronate

Actrapid

neutral insulin

Adalat

nifedipine

Adenoscan

adenosine

Adnisolone

prednisolone

Afemox

famotidine

Akineton

biperiden

Alclox

cloxacillin

Aldactone

spironolactone

Aldazine

thioridazine

Aldomet

methyldopa

Aledecin

beclomethasone

Alepam

oxazepam

Allegron

nortriptyline

Allohexal

allopurinol

Alodorm

nitrazepam

Alphapress

hydralazine

Alphapril

enalapril

Alprax 2

alprazolam

Alprim

trimetoprim

Amaryl

glimepiride

Amfamox

famotidine

Amoxil

amoxycillin

Amprace

enalapril

Amytal

amylobarbitone

Anafranil

clomipramine

Anamorph

morphine

Anaprox

naproxen

Anatensol

fluphenazine

Ancolan

meclozine

Andriol

testosterone

Androcur

cytoproterone

Anginine

glyceryl trinitrate

Anpec

verapamil

Antabuse

disulfiram

Antadine

amantadine

Antenex

diazepam

Anturan

sulphinpyrazone

Apresoline

hydralazine

Aprinox

bendrofluazide

Aptin

alprenolol

Aramine

metaraminol

Aratac

amiodarone

Arava

leflunomide

Arazide

hydrochlorthiazide + amiloride

Aredia

pamidronate

Arima

mocolobemide

Aropax

paroxetine

Artane

benzhexol

Arthrexin

indomethacin

Asasantin

dipyridamole + aspirin

Asig

quinapril

Asmol

salbutamol

Astrix

aspirin

Atacand

candesartan

Atacand plu

candesartan + hydrochlorthiazide

AtromidS

clofibrate

Atropt

atropine sulfate

Atrovent

ipratropium

Attenta

methylphenidate

Aurorix

moclobemide

Auselol

atenolol

Ausgem

Gemfibrozil

Auspril

Enalapril

Ausran

Ranitidine

Avanza

Mirtazipine

Avapro

Irbesartan

Avapro HCT

irbesartan = hydrochlorthiazide

 

Avomine

promethazine

Azol

danazol

Bactrim

trimethoprim &

sulphamethoxazoe

Banocrine

danazol

Barbaloc

pindolol

Beclaforte

beclamethasone

Beconase

beclamethasone

Becotide

beclamethasone

Benadryl

diphenhydramine

Benemid

probenecid

Benztrop

benztropine

Betasol

thiamine

Betaloc

metoprolol

Betamin

thiamine

Betnovate

betamethazone

Betoptic

betaxalol

Biquinate

suinine bisulphate

Bicor

bisoprolol

Biquin

quinine sulphate

Blocadren

timolol

Bonefos

sodium clodronate

Bricanyl

terbutaline

Brufen

ibuprofen

Bufferin

aspirin

Burinex

bumetanide

Buscopan

hyoscine

Cabaser

carbegoline

Cafergot

ergotamine

Calcitare

calcitonin

Calmoxyl duo

amoxycillin + clavulinate

Calsynar

calcitonin

Caltrate

calcium supp

Candyl

piroxicam

CandylD

priroxicam

Capadex

propoxyphen e + paracetamol

Captopen

captopril

Capurate

allopuinol

Capurate

allopurinol

Carafate

sucraflate

Cardinorm

amiodarone

Cardizem

diltiazem

Cardol

sotalol

Cartia

aspirin

Catapres

clonidine

Ceclor

cefaclor

Celepram

citalopram

Celestone

betamethasone

Cenestan

clotrimazole

Chlotride

chlorthiazide

Cibacalcin

calcitonin

Cilamox

amoxycillin

Cilicaine

procaine penicillin

Cimehexal

cimetidine

Claratyne

loratadine

Clexane

enoxaparin

Clinoril

sulindac

Clinoril

sulindac

Clofen

baclofen

Clomid

clomiphene

Clopixol

zuclopenthixol

Clozaril

clozapine

Codral forte

codeine & paracetamol

Cogentin

benzhexol

Colestid

cholestyramine

Colgout

colchicine

Compazine

prochlorperazine

Comtan

entacapone

Coras

diltiazem

Corbeton

oxprenolol

Cordarone

amiodarone

Cordilox

verapamil

Coumadin

warfarin

Coversil plus

indapamide + perindoprol

Coversyl

perindopril

Cozaar

losartan

Cyklokapron

tranexamic acid

Cytotec

misprostol

Daktarin

miconazole

Dalmane

flunitrazepam

Dantrium

dantrolene

Daonil

glibenclamide

Dapatabs

indapamide

Daraprim

pyrimethamine

Depomedrol

methylprednisilone

Deponit

glyceryl trintrate

Deptran

doxepin

Deralin

propanolol

Deseril

methysergide

Diabenase

chlorpropamide

Diabex

metformin

Diamicron

Gliclazide

Diamox

acetazolamide

Dibenyline

phenoxybenzamine

Diclotride

hydrochlorthiazide

Didronel

etidronate

Digesic

propoxyphen e + paracetamol

Dilatin

phenytoin

Dilatrend

carvedilol

Dilaudid

hydromorphone

Dilosyn

methdilazine

Diltahexl

diltiazem

Dilzem

diltiazem

Dindevan

phenidione

Diprosone

betamethasone

Dithiazide

hydroclorothiazide

Ditropan

oxybutynin

Dolibid

difusinal

Doloxene

propoxyphene

Donnatab

belladonna alkaloids

Dothep

dothiepin

Dozile

doxylamine

Ducene

diazepam

Duride

isosorbide M/N

Dyazide

hydrochlorthiazide +

triamterene

Dymadon

paracetamol

Ecotrin

aspirin

Edecril

ethacrynic acid

Enahexal

enalapril

Endep

amitriptyline

Endone

oxycodone

Enduron

methylclothiazide

Epilim

valproate

Epipen

adrenaline

Espar

paroxetine

Estraderm

oestradiol

Euglucon

glibenclamide

Euhypnos

temazepam

Exelon

rivastigmine

Fefol

iron supplement

Feldene

piroxicam

Felodur

felodipine

Fibsol

lisinopril

Flecatab

flacainide

Flixotide

fluticasone

Fluanxol

flupenthixol

Fosamax

alendronate

Fragmin

dalteparin

Frisium

clobazam

Fulcin

griseofulvin

Furadantin

nitrofurantoin

Gabatril

tiagabine

Gemhexal

gabapentin

Genox

tamoxifen

Glimel

gibenclamide

Glucophage

metformin

Gopten

trandilopril

Gopten

trandolapril

Halcion

triazolam

Halodol

haloperidol

Hiprex

hexamine

Humilin

neutral insulin

Hydopa

methyldopa

Hygroton

chlorthalidone

Hypnodorm

flunitrazepam

Hytrin

terazosin

Imdur

isosorbide

Imigran

sumtriptan

Imodium

loperamide

Imuran

azothiaprine

Indahexal

indapamide

Inderal

propanolol

Indocid

indomethacin

Intal

cromoglycate

Inza

naproxen

Ismelin

guanethidine

Isocover

clopidogrel

Isoptin

verapamil

Isordil

isosorbide

Isotrate

isosorbide

Jezil

gemfibrozil

Kalma

aplrazolam

Kaluril

amiloride

Kaponol

morphine

Karvea

irbesartan

Kripton

bromocriptine

Lamactil

lamotrogine

Lamasil

terbinafine

Lanoxin

digoxin

Laquenil

hydroxychloroquine

Largactil

chlorpromazine

Lasix

frusemide

Ledetrexate

methotrexate

Lescol

fluvastatin

Levophed

noradrenaline

Lexotan

bromazepam

Librium

chlordiazepoxide

Lipazil

gemfibrozil

Lipex

simvastatin

Lipitor

atorvastatin

Lipobay

cerivastatin

Liprace

lisonopril

Lomotil

diphenoxylate

Lopid

gemfibrozil

Lopressor

metoprolol

Losec

omeprazole

Lotremin

clotrimazole

Lurselle

probucol

Luvox

fluvoxamine

Macrodantin

nitrofurantoin

Madopar

levodopa +

benserazide

Magicul

cimetidine

Marevan

warfarin

Maxor

omeprazole

Mefic

mefenamic acid

Melipramine

imipramine

Melizide

glipizide

Melleril

thioridazine

Mersyndol

codeine + paracetamol + doxylamine

Mesasal

mesalazine

Mestinon

pyridostigmine

Metolol

metoprolol

Micardis

telmisartan

Micardis plus

telmisartan + HCZ

Midamor

amiloride

Minax

metoprolol

Minidiab

glipizide

Minitran

glyceryl trintirate

Minpress

prazosin

Mobic

meloxicam

Mobilis

piroxicam

Modecate

fluphenazine

Moduretic

hydrochlorthiazide + amiloride

Monodur

isosorbide mononitrate

Monoplu

fosinopril + HCZ

Monoplus

fosinopril

Monopril

fosinopril

Motilium

domeridone

Movox

fluvoxamine

MS Contin

morphine SR

Murelax

oxazepam

Mycrosin

aurothiomalate

Myoquin

quinine bisulphate

Mysoline

primidone

Napamide

indapamide

Naprosyn

naproxen

Nardil

phenelzine

Natrilix

indapamide

Navidrex

cyclopentathiazide

Negram

nalidixic acid

NeoMecazole

carbimazole

Neoral

cyclosporin

Neulactil

pericyazine

Neurotonin

gabapentin

Nexium

esomeprazole

Nifehexal

nifedipine

Nimotop

nimodipine

Nitradisc

glyceryl trintrate

Nolvadex

tamoxifen

Norgesic

orphenadrine

Normison

temazepam

Norpace

disopyramide

Norvasc

amlodipine

Noten

atenolol

Nyefax

nifedipine

Odrix

trandilopril

Ogen

piperazine

Orap

pimozide

Orudis

ketoprofen

Oruvail

ketoprofen

Ospelot

sulthiame

Ostelin

ergocalciferol

Oxetine

paroxetine

OxyNorm

oxycodone

Pamisol

pamidronate

Panadeine forte

codeine + paracetamol

Panafcort

prednisilone

Panamax

paracetamol

Paralgin

paracetamol

Pariet

rabaprazole

Parlodel

bromcriptine

Parnate

tranylcypromine

Parodex

propoxyphene + paracetamol

Paxam

clonazepam

Paxtine

paroxetine

Pendine

gabapentin

Pepcidine

famotidine

Permarin

oestrogens

Permax

pergolide

Persantin

dipyridamole

Pexid

perhexiline

Phenergan

promethazine

Phospholine

ecothiopate

Physeptone

methadone

Pilopt

pilocarpine

PirohexalD

piroxicam

Placil

clompiramine

Plavix

clopedogrel

Plendil

felodipine

Poladone

oxycodone

Ponstan

mefenamic acid

Pramin

metoclopramide

Presolol

labetolol

Pressin

prazosin

Primicor

milnirone

Prinivil

lisinopril

ProCid

probenicid

Probitor

omprazole

Progout

allopurinol

Prominal

phenobarbitone

Pronestyl

procainamide

Prothiaden

Dothiepin

Proxen

naproxen

Prozac

fluoxetine

Pulmicort

budesonide

Quilonum

lithium

Quinate

quinine sulphate

Quinoctal

quinine bisulphate

Rafen

ibuprofen

Ramace

ramapril

Rani 2

raniditine

Ranihexal

raniditine

Ranoxyl

ranitidine

Rastinon

tolbutamide

Razolam

alprazolam

Rebif

reboxitine

Remeron

mitazipine

Reminal

galantamine

Renitec plus

enalapril = hydrochlorthiazide

Risperdal

risperidone

Ritalin

methylphenindate

Rivotril

clonazepam

Roaccutane

isoretinoin

Rohynol

flunitrazepam

Rosig

piroxicam

Rulide

roxithromycin

Rythmodan

disopyramide

Rythmodan

disopyramide

Sabril

vigabatrin

Salazoprin

sulphasalazine

Sandimmum

cyclosporin

Sandomigran

pizotifen

Selgene

selegiline

Serc

betahistidine

Serenace

haloperidol

Serepax

oxazepam

Serevent

salmeterol

Seritide

salmeterol + fluticasone

Seroquel

quetiapine

Serovent

salmeterol

Serzone

nerfazodone

Sigmetadine

cimetidine

Sinemet

Levodopa + carbidopa

Sinequan

Doxepin

Sitriol

calcitrol

Skelid

tiludronate

SlowK

potassium supp

Solavert

sotalol

Solian

amisolpride

Solone

prednisilone

Solprin

aspirin

Somac

pantoprazole

Sone

prednisilone

Sorbidin

isosorbide D/N

Sotab

sotalol

Sotacor

sotalol

Sotahexal

sotalol

Spren

aspirin

Stelazine

trifluoperazine

Stemazine

prochlorperazine

Surgam

tiaprofenic acid

Surmontil

trimipramine

Symmetrel

amantadine

Tagamet

cimetidine

Talohexal

citalopram

Tambocor

flecainide

Tazac

nizatidine

Tegretol

carbamazepine

Teldane

terfenadine

Temaze

Temazepam

 

Temtabs

temazepam

Tenopt

Timolol

Tenormin

Atenolol

Tensig

Atenolol

Teril

carbamazepine

TheorDur

theophylline

Ticild

Ticlopidine

Tilade

Nedocromil

Tilcotil

tenoxicam

Timoptol

timolol

Tolvon

mianserin

Topace

captopril

Topamax

topiramate

Trandate

labetolol

Transderm

glyceryl trinitrate

Travacalm

hyoscine

Travatan

travoprost

Trental

oxpentifylline

Trileptal

oxcarbazepine

Tritace

ramapril

Tryptanol

amitriptyline

Tylenol

paracetamol

Unisom

diphenhydramine

Ural

sodium citrate

Urex

frusemide

Valium

diazepam

Valpam 2

diazepam

Valpro

valproate

Vasocardol

diltiazem

Vastin

fluvastatin

Ventolin

salbutamol

Veracaps

verapamil

Vioxx

rofexcoxib

Visken

pindolol

Voltaren

diclofenac

Xalantan

latanoprost

Xanax

alprazolam

Zactin

fluoxetine

Zandip

lecanidipine

Zantac

ranitidine

Zarotin

ethosuxemide

Zestril

lisinopril

Zocor

simvastatin

Zoloft

sertraline

Zomig

zolmitriptan

Zoton

lansoprazole

 

 

Zydol

tramadol

Zyloprim

allopurinol

Zyprex

olanzapine

Zyprexa

olanzapine

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Index


AAA repairs, 16, 19

abdominal aneurysm, 16

Abdominoplasty, 15

ACE inhibitors, 29, 56, 71

CKD, 93

admit

when, 11

adverse cardiac events

tachycardia, 66

warning sign, 66

agitation

alcoholism, 101

airway

assessment, 116

Mallampati test, 116

albumin

surgery and, 110

albuminuria, 94

alcohol, 21, 65, 72, 99, 100, 101, 105, 120

withdrawal, 100

alcoholism, 99

allergy

latex, 101

opioids, 101

penicillin, 101

radiocontrast media, 101

sticky tapes, 102

sulfa, 101

allopurinol

aspirin ., 26

AMI, 41, 51, 60, 61

abnormal endothelium, 64

and AF, 65

anaemia

causes, 29, 47

chronic signs of, 47

anaesthesia

risks of, 29

angina, 60

stable, 51

antidepressants

what to stop, 28

antipsychotics

what to stop, 28

anxiety, 119

Apfel’s risk score, 118

apronectomy, 15

arrhythmia

alcohol, 101

ventricular, 51

Asasantin®, 40

aspiration

gastric, 32

prophylaxis, 33

wheeze, 82

aspirin, 18, 26, 29, 32, 39, 40, 46, 58, 61, 65, 85, 123, 124, 125

when to stop, 39

assessment

nutrition

subjective global score, 109

asthma, 28, 58, 79, 80, 81, 82, 85, 86, 101

dyspnoea, 104

medication, 85

morphine OK, 118

viral induced, 85

Asthma, 85

blood gases and, 85

asthma:, 85

atrial fibrillation

causes, 64

awareness, 33

azothioprine, 25

back pain, 30

bariatric precautions, 111

bicarbonate

high, 88

bigeminy, 65

bleeders

investigations, 23

block

heart, 67

blood

autologous, 47

blood glucose - routine, 22

blood transfusion, 11, 12, 24, 28, 31, 34, 47, 49, 61, 84, 115

autologous, 48

guided donations, 48

predonated, 47

red tape, 47

who needs it, 47

blood volume

ages, 121

BMI, 20, 33, 58, 71, 75, 85, 109

reading, 109

BMS

bare metal stent, 60, 61

bone marrow biopsy, 46

bowel prep, 120

diabetics. See

bowel resection, 13

brachial plexus block

risks of, 30

breast

feeding, 114

breast feeding, 114

breast milk, 32

bundle branch blocks, 52

Caesarean section, 33, 44, 50, 115

CAM

toxic sometimes., 26

cardiac arrhythmias

SVT, 64

Cardiac arrhythmias, 51

cardiac failure, 9, 10, 21, 23, 28, 47, 48, 55, 66, 69, 70, 71, 81, 82, 91, 97, 103

anaesthetic requirements, 69

congestive, 55

consequences, 69

dyspnoea, 104

hypertension, 56

markers, 70

mild, 71

NSAIDs, 26

optimization, 70

pulmonary hypertension, 86

right sided, 88

severe, 71

sleep apnoea, 89

undiagnosed, 69

what happens, 55

with murmur, 73

cardiac risk, 55

cardioversion

elective, 65

carotid

endarterectomy, 17

carotid endarterectomy, 17

hypertension, 52

celecoxib, 26, 40, 101

chemotherapeutic agents, 25

chest infection, 80

children

respiratory tract infection, 81

snotty nose, 81

snotty noses, 81

URTI, 81

cholecystectomy

laparoscopic, 14

chronic kidney disease, 93

cirrhosis

drugs, 107

Pugh’s classification;, 107

cis-platinum, 25

CKD, 42, 53, 54, 93, 94

MDRD calculator, 94

refer to, 93

underdiagnosed, 94

clopidogrel

when to stop, 40

clotting studies

indications, 22

clubbed

fingers, 79

coagulation

minimal requirements, 102

cognitive disorder, 35

colonoscopy

bowel prep, 121

colophony, 102

conditioned reflexes, 35

consent, 11

contraceptive pills

management, 114

cor pulmonale, 88

Cor pulmonale, 88

coronary angiography, 60

cough

nocturnal, 52

persistent, 81

COX inhibitors, 24

Crockoft Gault formula, 93

CT scans, 21

CXR

indications, 21

cyanosis, 103

cylcophosphamide, 25

cystoscopy, 17

cystscopy, 17

dalteparin, 41

dementia, 119

dental disease, 33

depression, 105

DES

drug eluting stent, 61

diabetes

insulin therapy, 97

type 2, 98

type I, 97

diabetics

investigations, 23

diastolic failure

definition, 72

dipyridamole

when to stop, 40

Dipyridamole, 40

dizziness

driving

after anaesthesia, 35

droperidol, 119

drug

interactions, 26

DTs, 100

DVT, 14, 15, 17, 18, 19, 29, 34, 38, 40, 41, 42, 115, 119

abnormal endothelium, 64

diabetes, 99

HRT, 114

dysarthria, 103

dysphagia, 104

dysphasia, 103

dyspnoea, 70, 104

causes, 104

on exertion, 69

ear infections, 80

ECG

indications, 20

T-waves, 70

echocardiography, 23, 88

for valve disease, 74

stress, 58

Echocardiography

transoesophageal, 75

transthoracic, 75

ECOG performance scale, 37

eGFR

IHD and, 55

ejection fraction, 23, 70, 72

emotional status, 119

endocarditis

prophylaxis, 75

endothelial syndrome, 64

endothelium, 63

enoxaparin, 41

Epidural

backpain, 30

epidural haematomas, 30

Epidural haematomas, 30

epilepsy

how to manage, 104

investigations, 23

ESWL, 18

exercise capacity, 36

how to quantify, 36

extracorporeal shock wave lithotripsy, 18

extrasystoles

ventricular. See

eye drops

ecothiopate, 28

falls, 28

fasting

all about it, 32

fluids, 32

food, 32

FFP

= fresh frozen plasma, 43

Fluids

volume depletion, 95

volume overload, 95

fresh frozen plasma

warfarin, 43

gastric reduction, 14

gingival disease, 33

Glucosamine, 27

glucose - routine, 22

Glycated tissues, 98

Golightly, 120

goodness only knows, 105

graduated elastic compression stockings

TURPS, 17

GTN, 39, 58, 63

spray, 63

haemochromatosis, 105

haemophilia, 46

HbA1C, 99

headache

dural puncture, 34

postanaesthetic, 34

heart block, 67

bifasicular, 67

heart failure

refer to, 52

Heart failure, 52

heart valves

mechanical, 74

Herbal remedies, 26

Hip replacement, 19

Hospital stay, 29

hrombophelebitis, 119

HRT, 114

hyperparathyroidism, 105

hypertension

acceptable levels, 56

pulmonary, 82

symptomatic, 52

unacceptable, 56

white coat, 56

Hypertension, 52

hyperthyroidism, 113

hypoglycaemic drugs, 32, 98

oral, 98

hypotension

epidural anaesthesia, 30

hypothyroidism, 20, 112

myxoedema, 112

hypoxia, 37

ICU

predict need for, 92

IHD

stable, 57

infecion

intercurrent, 104

infections

intercurrent, 9

respiratory tract, 9

inflammatory mediators, 64

influenza, 80

INR/aPPT, 45

insulin, 97, 98, 123, 124

dosing, 97

ketones, 97

surgery, 97

investigations

laboratory, 20

iron studies, 23

ischaemic heart disease, 60

investigations, 23

new, 58

risk factors, 58

stents, 61

jewellery

body, 34

kidney disease

chronic, 94

LAHB

left anterior hemiblock, 67, 77, 78

latex allergy, 101

Left anterior hemiblock, 78

LFTs

indications, 20

lithotripsy, 18

liver function tests, 21

LMWH, 30, 38, 39, 41, 42, 43, 114

spinals, 43

with IHD, 58

Lucozade, 121

lung

aspiration, 82

bronchiectasis, 82

bronchopleural fistula, 82

bronchospasm, 82

function tests, 23

wheezes, 82

lung resection, 16

MAC attack, 64, 99

magnesium

hypomagnesaemia, 71

magnetic resonance imaging, 22

malignant hyperpyrexia, 30

Mallampati test

airway, 116

malnutrition, 33, 108

albumin, 110

oesophagectomy, 13

MAOIs, 24

marijuana, 82, 105

Maxalon, 118

MDRD formula, 94

medication

elderly, 26

generic names, 25

on day of surgery, 24, 32

meloxicam, 26

Mendleson’s syndrome;, 115

mental

impairment, 11

retardation, 11

MET score, 36

metabolic rate, 117

metformin

dangers, 98

midazolam, 35

Mitral valve

replacements, 75

moclobemide

when to stop, 24

morphine

blood pressure, 118

Morphine, 118

MRI, 22

murmur

grading, 73

murmurs

types, 73

myxoedema, 112

natural remedies, 24

nausea, 119

nitric oxide,, 63

nocturia, 71

CCF, 70

diabetes, 98

pitting oedema, 111

NSAIDs, 7, 14, 24, 26, 28, 29, 32, 40, 43, 46, 70, 85, 88, 93, 116, 121

when to stop, 24, 40

NSAIDS

elderly and., 26

obese

cardiac function, 111

obesity, 8, 20, 58

OCP, 114

oedema

causes, 111

lymphoedema, 71

myxoedema, 71

peripheral, 82

peripheral, 88

pitting, 71, 111

oesphagectomy, 13

opioids, 88

liver function, 106

orthopnoea

blood gases, 82

otitis media, 80

oximeter

how to interpret, 82

oxygen, 19, 20, 33, 34, 36, 37, 49, 53, 55, 58, 63, 71, 84, 86, 88, 89, 90, 91, 116, 117, 118

blood gases, 82

PACE, 9, 10, 53, 54, 56, 65

arryhthmias, 64

heart block, 67

pitting oedema, 71

surgery and, 55

WCHT, 56

pacemaker

check, 68

function, 68

preoperative check, 68

types, 68

Pacemakers, 52

PaCO2, 84, 88

pain, 34, 117

back, 30

after epidural, 30

harms, 117

management, 116

Pain, 116

pain scale, 117

palpitations

causes, 66

para-angina, 62

PCA

= patient controlled analgesia, 82

Pemberton’s sign, 113

Perioperative adverse cardiac event, 10

peripheral vascular disease

hypertension and, 52

pernicious anaemia, 106

pH, 32, 55, 82

gastric, 32

how to interpret, 83

PHT

= pulmonary hypertension, 86

physiotherapy

referral, 85

techniques, 84

Pickwickian syndrome, 88

Picoprep, 120

piercings, 34

plasma

volume, 121

platelets, 15, 23, 39, 40, 48, 49

packs, 49

pooled, 48

postoperative

activity restrictions, 35

residual drug effects, 35

Postoperative cognitive disorder.

postpone

anaesthesia, 11

PRAT score, 85

pregnancy, 114

prostate

radical operation, 17

prostatectomy

radical, 17

TURP, 18

proteinuria, 94

Prothrombinex-HT, 43

awareness, 33

PTCA, 51

pulmonary

hypertension

blood gases, 82

Pulmonary hypertension, 86

pulse oximeter, 37, 82

misleading, 90

stress test, 54

pulse pressure

excessive, 56

Q-waves

pathological, 78

radiation hazards, 21

raloxifine, 115

Red Cross Transfusion, 48

reflux

aspiration, 91

obesity, 111

respiratory

function

tests, 23

respiratory function tests, 82

respiratory infections, 80

respiratory rate, 13, 82, 118

restrictive lung disease, 86

rheumatoir arthritis

investigations, 112

schizophrenia

wound healing, 119

SERMs, 115

shock, 50

sick sinus syndrome, 67

sickle cell, 106

skin

bleeding times

? useless, 108

sleep apnoea, 26, 66, 70, 79, 86, 88, 89, 90

obstructive, 90

smoker

palpitations, 66

risk, 79

smokers

CXR for, 24

smoking, 79

sodium

lethal wateroverload, 114

spinal anaesthesia

risks of, 30

spirometry

when to order, 82

splenectomy, 15

sputum

coloured, 81

infected, 80

SSRI, 28, 46

SSRIs

do not stop, 40

statin

and gemfibrozil, 25

and nicotinic acid, 25

nasty combos, 25

with IHD, 58

stents, 61

sternal split, 15

steroid

supplement, 85

steroids

equivalent doses, 27

when to supplement, 27

storage lesion, 90

strokes

recent, 102

subjective global assessment, 109

surgery

site identification, 11

surgery

major and minor, 10

major, minor, 10

surgery

how to postpone, 11

surgery

recovery times, 34

surgery

vascular, 55

syncope, 112

systolic dysfunction

definition, 72

tach-brady syndrome, 68

tamoxifen, 115

teeth

caps, crowns, 33

chipped, 30

damage, 33

thallassaemia, 106

theophylline, 85

thyroid

function tests, 23

TIA, 9, 40, 64, 102

TIAs

recent, 102

tissue damage

effects of, 55

tongue studs, 34

total cystectomy, 18

triple whammy, 93

tropinin T, 22

TURP, 18

urinary catheters, 34

urinary tract infection

elderly, 105

URTI, 80, 81

valerian

don't stop, 27

valproic acid, 28

valvular heart disease, 74

vascular surgery

AAA repair, 16

carotid, 17

infra-inguinal, 17

veins, 119

access, 119

ventricular

arrhythymia:, 64

bigeminy, 65

ectopics, 64

extrasystoles, 65

ventricular tachycardia, 52

VEs, 65

vitamin

preop supplements, 13

Vitamin K1, 43

voice

horase, 103

volumes

blood, 121

plasma, 121

vomiting, 118

von Willebrands disease, 46

warfarin

how to manage, 41

how to reverse, 43

WCHT = white coate hypertension, 56

Wernicke’s encephalopathy, 100

wheeze

causes, 82

forced expiration and, 81

marijuana, 82

nocturnal, 52