infarction of the bowel

Question 1

tell me about acute mesenteric ischaemia

Answer 1

caused by an embolism resulting in occlusion of an artery which supplies the small bowel, for example the superior mesenteric artery. Classically patients have a history of atrial fibrillation.

The abdominal pain is typically severe, of sudden onset and out-of-keeping with physical exam findings.

urgent surgery is usually required
poor prognosis, especially if surgery delayed

Question 2

Ischaemiac colitis

Answer 2

Ischaemic colitis describes an acute but transient compromise in the blood flow to the large bowel. This may lead to inflammation, ulceration and haemorrhage. It is more likely to occur in ‘watershed’ areas such as the splenic flexure that are located at the borders of the territory supplied by the superior and inferior mesenteric arteries.

Investigations
‘thumbprinting’ may be seen on abdominal x-ray due to mucosal oedema/haemorrhage

Management

• usually supportive
• surgery may be required in a minority of cases if conservative measures fail. Indications would include generalised peritonitis, perforation or ongoing haemorrhage

Question 3

Common predisposing factors of bowel ischaemia

Answer 3

increasing age
atrial fibrillation - particularly for mesenteric ischaemia
other causes of emboli: endocarditis, malignancy
cardiovascular disease risk factors: smoking, hypertension, diabetes
cocaine: ischaemic colitis is sometimes seen in young patients following cocaine use

Question 4

Common features of bowel ischaemia

Answer 4

abdominal pain - in acute mesenteric ischaemia this is often of sudden onset, severe and out-of-keeping with physical exam findings
rectal bleeding
diarrhoea
fever
bloods typically show an elevated white blood cell count associated with a lactic acidosis

Question 5

What is the best investigation to do to confirm acute mesenteric ischaemia

Answer 5

serum lactate