Routine analysis of cirrhotic ascites for evidence of infection - not worth the effort?

Spontaneous bacterial peritonitis (SBP) is a serious complication of advanced cirrhosis of the liver. Usually patients with SBP show symptoms such as fever, abdominal pain, worsening of renal function, hypotension or development of encephalopathy. The frequency of SBP among hospital-ised patients with advanced cirrhosis varies from 10% to 30% [1]. The mortality of SBP was 80% to 100% in the 1960s, but has declined to 30% to 40% with early diagnosis and effective therapy with broad-spectrum antibiotics [2, 3]. A high index of suspicion followed by analysis of ascitic fluid for evidence of infection is helpful in making an early diagnosis of SBP, and is today considered the standard of care in patients with cirrhosis and symptoms listed above. The International Ascites Club recommends mandatory analysis of ascitic fluid in all cases of new onset of ascites, worsening of ascites, and in all other cases whenever there is a suspicion of SBP [1]. The recommendations of the American Association for the Study of Liver Disease (AASLD) differ from those of the International Ascites Club. The AASLD thus recommends testing of ascitic fluid for cell count and differential count, but not necessarily culture, for patients undergoing serial outpatient therapeutic para-centesis, each time the fluid is removed [4]. Given the low prevalence of SBP in asymptomatic patients, the question is whether we need to undertake ascitic fluid cell count routinely in all cases of paracentesis. This issue is of particular importance for gastroenterologists and physicians in India and other developing countries, since such testing entails extra cost. Based on the results of absolute white cell count and culture of the ascitic fluid, five variants of peritoneal fluid infection have been recognised [1]. These are: (1) SBP: absolute count of polymorphonuclear leucocytes (PMN) in ascitic fluid >250/mm 3 with a positive culture showing a single type of bacteria; (2) culture-negative neutrocytic ascites (CNNA): negative ascitic fluid culture with PMN count of >250/mm 3 ; (3) mono-microbial non-neutrocytic bacterascites (MNB): ascitic fluid culture positive for one type of bacteria and PMN count of <250/mm 3 ; (4) secondary bacterial peritonitis: characterized by polymicrobial growth from ascitic fluid with PMN >250/mm 3 and a surgically-treatable source of infection; and, (5) polymicrobial bacter-ascites with PMN count <250/mm 3. SBP may sometimes be asymptomatic or present with atypical symptoms. In one study, clinical suspicion based on presence of symptoms of SBP in an emergency room setting had …