23rd August 2023

A 50-year-old male with a history of alcoholism presents to the hospital with severe abdominal pain and distension

A 50-year-old male with a history of alcoholism presents to the hospital with severe abdominal pain and distension. On examination, the patient has ascites and rebound tenderness in the abdomen. Paracentesis reveals cloudy ascitic fluid.

Which laboratory test is most important for diagnosing spontaneous bacterial peritonitis?