Spontaneous bacterial peritonitis in asymptomatic outpatients with cirrhotic ascites.

The prevalence and natural history of spontaneous bacterial peritonitis in asymptomatic patients with ascites secondary to cirrhosis is unknown. From a prospectively recorded database, we reviewed the clinical and laboratory features of all outpatients with cirrhotic ascites undergoing paracentesis between July 1994 and December 2000. The prevalence of spontaneous bacterial peritonitis in the population of 427 cirrhotic outpatients as defined by neutrocytic ascites (absolute neutrophil count >or=250 cells/mm(3)) was 3.5%. Of the 15 patients with neutrocytic ascites, 6 were culture positive (1.4%) and 9 culture negative (2.1%). Eight other patients (1.9%) had bacterascites. The organisms cultured from ascitic fluid in these asymptomatic patients with culture positive neutrocytic ascites and bacterascites were predominantly gram positive. No patient developed hepatorenal syndrome, and 1-year survival of 67% was better than historical data from hospitalized patients with spontaneous bacterial peritonitis. Moreover, patients who did not receive antibiotics for neutrocytic ascites fared no worse than patients who did receive antibiotics. In conclusion, spontaneous bacterial peritonitis in outpatients with cirrhotic ascites is less frequent, occurs in patients with less advanced liver disease, and may have a better outcome than its counterpart in hospitalized patients. In addition, the organisms cultured from ascitic fluid in outpatients are predominantly gram positive. A reassessment of diagnostic criteria for spontaneous bacterial peritonitis in outpatients may be required.