Diagnostic parameters for spontaneous bacterial peritonitis in hepatitis B-related cirrhosis: comparison of ascitic fluid polymorphonuclear cell count, lactate and pH values.

BACKGROUND:The clinical value of ascitic fluid pH or lactate in the diagnosis of spontaneous bacterial peritonitis was debated in alcoholic cirrhosis. It was rarely discussed in hepatitis B-related cirrhosis. We investigated the best rapid diagnostic method in spontaneous bacterial peritonitis of patients with hepatitis B-related cirrhosis. METHODS:Ascitic fluid polymorphonuclear cell count, ascitic fluid pH, arterial-ascitic fluid pH gradient, ascitic fluid lactate, and arterial-ascitic fluid lactate gradient were analyzed in 79 patients with sterile portal hypertension-related ascites, 31 patients with spontaneous bacterial peritonitis, 16 patients with hepatocellular carcinoma, 15 patients with malignancy-related ascites and 9 patients with other miscellaneous diseases. RESULTS:The sensitivity, specificity and accuracy of the diagnosis of spontaneous bacterial peritonitis were 100, 94 and 95% with the cut-off value of an ascitic fluid polymorphonuclear cell count > or = 250 cells/mm3, and were 86, 98 and 96% with that value > or = 500 cells/mm3, respectively. The sensitivity, specificity and accuracy were 29, 92, 80% using ascitic fluid pH < or = 7.35 as a cut-off value; 38, 91, 82% using arterial-ascitic fluid pH gradient > or = 0.1 as a cut-off value; 52, 92, 85% using ascitic fluid lactate > or = 32 mg/dL as a cut-off value, and 38, 96, 85% using arterial-ascitic fluid lactate gradient > or = 20 mg/dL as a cut-off value. CONCLUSIONS:The sensitivity of ascitic fluid pH or lactate was too low to aid in a diagnosis of spontaneous bacterial peritonitis in hepatitis B-related cirrhosis in spite of the acceptable specificity. An ascitic fluid polymorphonuclear cell count > or = 250 cells/mm3 or > or = 500 cells/mm3 was the major and appropriate aids in the rapid diagnosis of spontaneous bacterial peritonitis.