Spontaneous bacterial peritonitis in cirrhosis. Incidence, diagnosis, and prognosis.

Among 342 consecutive patients admitted to the hospital with cirrhosis of the liver 68 (17%) had ascites and had a diagnostic paracentesis performed. Fourteen episodes of peritonitis were diagnosed in 13 patients, which is an overall incidence of peritonitis of 19%. The incidence of peritonitis was 36% in patients with hepatic encephalopathy and 10% in patients without hepatic encephalopathy (P less than 0.01). In all except one case the infecting organism was most likely of enteric origin--that is, gram-negative or anaerobic species. The infected patients had lower mean ascites pH and higher mean ascites leukocyte and polymorphonuclear cell counts than non-infected patients. However, there was a considerable overlap between the two groups, and the diagnostic sensitivity did not exceed 65% for any of these three features. The survival of infected patients without encephalopathy was 33%, which was significantly lower (P less than 0.05) than that the 89% for non-infected patients. In patients with encephalopathy the survival was identical for infected and non-infected patients.