Spontaneous bacterial peritonitis: variant syndromes.

Spontaneous bacterial peritonitis (SBP), a fascinating disease that had been reported perhaps 50 times in varying guises over the preceding century, suddenly burst forth in the 1960s and was recognized in clusters of cases almost simultaneously in Paris, London, and West Haven, Connecticut. The spectrum of the disease has broadened. Initially, it was associated almost exclusively with alcoholic cirrhosis, but it has now been found in association with posthepatitic cirrhosis, cryptogenic cirrhosis, chronic active liver disease, and, occasionally, in biliary cirrhosis and cardiac cirrhosis. Recently, it has been reported in alcoholic hepatitis and acute viral hepatitis. It occurs occasionally in malignant ascites and in pancreatitis in the absence of cirrhosis. It is surprisingly common in disseminated lupus, in which it occurs relatively more commonly than in alcoholic cirrhosis. A similar syndrome, primary peritonitis, occurs frequently in children with nephrotic ascites. The clinical pattern of SBP has broadened. Initially it consisted of abdominal pain, fever, rebound tenderness, hypoactive bowel sounds, hypotension, encephalopathy, and cloudy ascites with large numbers of polymorphonuclear leukocytes in ascitic fluid. Each and every symptom, sign, and laboratory abnormality may be absent; indeed, the syndrome can be completely silent. Initially, the causative bacteria appeared to be almost exclusively enteric, but now the list of bacteria isolated in cases of SBP looks like a bacteriology textbook. Anaerobes are rare. Multiple organisms usually suggest nonspontaneous origin such as perforation or vasopressin induction. The differentiation between spontaneous and nonspontaneous bacterial peritonitis is crucial in the differential diagnosis. The great majority of cases of SBP develop in the hospital, 80% more than one week after admission. It is therefore a nosocomial disease that may be precipitated by procedure-induced bacteremia, gastrointestinal bleeding, or diarrhea, and it tends to occur in patients with low ascitic fluid protein (complement) concentrations and severe portal-systemic shunting.