skip to main content

Spontaneous bacterial peritonitis — MCCQE Part 1 MCQ

Instant feedback + full explanation. One question, done properly.

HardAbdominal PainSpontaneous bacterial peritonitisMCCQE Part 1

A 58-year-old man with known cirrhosis presents with fever, confusion, and increasing abdominal distension. He has shifting dullness and diffuse mild abdominal tenderness. WBC is 15 x 10^9/L, bilirubin is elevated, and creatinine is above baseline. What is the most appropriate investigation?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: C — Diagnostic paracentesis with ascitic cell count and culture

Any hospitalised patient with cirrhosis and ascites who has fever, encephalopathy, abdominal pain, or renal deterioration needs prompt diagnostic paracentesis to assess for spontaneous bacterial peritonitis. CT can be useful in selected cases, but it should not delay paracentesis. Serum ammonia does not diagnose infection and poorly correlates with encephalopathy severity. Hepatitis serology may be relevant later but does not address the acute presentation.

Reference: Canadian Association for the Study of the Liver cirrhosis guidance