[Spontaneous bacterial peritonitis: diagnostic and prognostic aspects]

Spontaneous bacterial peritonitis (SBP) is a frequent complication of cirrhosis with ascites. As clinical symptoms are often mild or lacking, the condition may not be perceived in otherwise severely ill patients. This study focuses on diagnostic and prognostic aspects in 25 patients with 26 episodes of SBP. A microbiological diagnosis was established in 18 patients by positive culture of ascitic fluid or positive gram stain. In 8 episodes the diagnosis was presumed on the basis of an elevated polymorphonuclear leukocyte (PMN) count in the ascitic fluid (> 250 PMN/microliters). The mean (+/- SD) age of the 11 women and 14 men was 55 +/- 14 years; 16 were attributed to Child grade C, 9 to Child grade B liver dysfunction. In 19 cases, cirrhosis was confirmed histologically. The underlying liver disease was Laennec's cirrhosis in 13 cases, hepatitis-B virus associated chronic liver disease in 7 cases and primary biliary cirrhosis in 2 cases. At the time of diagnosis, 6 of 25 patients had no fever, 13 of 25 patients had no abdominal pain, 10 of 24 patients showed no abdominal tenderness upon palpation and 5 of 26 patients had no fever or abdominal pain. 17 of 26 patients showed signs of portosystemic encephalopathy. The total white blood cell count in the ascitic fluid was 3627 +/- 3978/microliters with 71 +/- 29% polymorphonuclear cells in the group with microbiologically proven peritonitis and 5105 +/- 2860 cells/microliters (80 +/- 13%) in the group with negative ascitic fluid culture, respectively. Gram stains were positive in 8 cases and culture in 16 of 25 patients. E. coli was cultured in 8 episodes and Str. pneumoniae in two. In-hospital mortality was 61% in the group with microbiologically proven peritonitis and 14% in the group with negative ascitic fluid culture (p = 0.062); 6-month mortality rate was 78% and 86% respectively (p = 0.91). Prognosis was worse in patients Child grade C (p = 0.027), in patients lacking symptoms or signs of peritoneal irritation (p = 0.017), in patients with septic shock (p = 0.018) and in patients with elevated serum-creatinin levels at the time of diagnosis (p = 0.05). SBP is a treatable complication with high mortality of advanced liver disease. Clinical manifestations may be non-specific or absent. We recommend that diagnostic paracentesis be performed in all patients with cirrhosis and ascites if their clinical condition is rapidly worsening.