Acute mesenteric ischaemia

A 55-year-old man with a history of peripheral vascular disease presents with severe abdominal pain out of proportion to examination. He has AF and is hypotensive. What is the most likely diagnosis?

A) Acute appendicitis
B) Small bowel obstruction
C) Acute mesenteric ischaemia
D) Peptic ulcer perforation
E) Diverticulitis

Correct Answer:

C) Acute mesenteric ischaemia

Explanation:

Acute mesenteric ischaemia presents with sudden, severe abdominal pain out of proportion to examination, often in patients with atrial fibrillation (causing embolism) or peripheral vascular disease.

• A) Acute appendicitis → Incorrect. Typically causes RLQ pain, not severe generalised pain.
• B) Small bowel obstruction → Incorrect. Causes colicky pain and vomiting, but not severe pain out of proportion.
• D) Peptic ulcer perforation → Incorrect. Causes sudden onset pain + peritonitis but not linked to AF.
• E) Diverticulitis → Incorrect. Causes LLQ pain with fever, not severe, diffuse pain.

Key Tips for PLAB 1:

✅ Acute mesenteric ischaemia = Severe pain + minimal findings + AF/PVD history.
✅ Diagnosis = CT angiography.
✅ Treatment = Urgent surgical revascularisation.