Case 101: Massive bleeding per rectum
A 73 year old man presents via ambulance after collapsing at home. He has been passing large amounts of blood per rectum. He is currently haemodynamically stable after 1000ml IV saline. The nurse looking after him brings you a pan to inspect.
1. Where do you think this blood is originating and what are the common causes?
It can be difficult, and potentially unreliable, to predict the source of blood loss simply from its appearance. This blood appears to be of colonic origin. Bright red blood bleeding from an upper gastrointestinal source is typically associated with significant haemodynamic instability due to the rapid rate of bleeding.
The common causes of massive colonic bleeding are diverticular disease and angiodysplasia. Neoplasms (carcinomas and adenomas) are uncommon causes of this degree of blood loss. Colitis (IBD, infective, inflammatory, ischaemic etc) are typically associated with bloody diarrhoea rather than massive PR bleeding.
2. How would you investigate this man to determine the source of bleeding?
In an unstable patient it is critical to exclude an upper GI source of bleeding with an urgent gastroscopy. A nasogastric tube may help as the finding of clean bile is evidence against an upper GI source.
The options for investigating colonic bleeding include CT angiography, routine mesenteric angiography, labelled red blood cell nuclear scintigraphy and colonoscopy. Each has benefits and limitations. The choice of first line investigation is often determined by local expertise.
3. When would you operate on this man?
This may be a difficult decision to make. The key features to consider are haemodynamic stability and transfusion equirements, the results of localisation studies, recurrence of bleeding and the patient's general fitness.
An unstable patient failing to respond to IV resuscitation requires urgent definitive surgery however the mortality rate of blind total colectomy in this situation is high.
Ongoing or recurrent bleeding requiring more than 6 units of blood in 24 hours indicates failure of the conservative approach.
An unfit patient with significant comorbidites is likely to tolerate an emergency laparotomy for colectomy poorly, however it must be remembered that waiting until they become unstable to make the decision to operate is likely to worsen their outcome.