Significance of ascitic fluid white blood cells, pH, lactate, and other chemistry in immediate diagnosis of spontaneous bacterial peritonitis.

From 1989 to 1991, 68 cirrhotic patients, 47 with uninfected ascites and 21 with SBP were studied for the significance of ascitic fluid pH, lactate, PMN count and other chemistry for immediate diagnosis of SBP. It was revealed that ascitic fluid PMN count if over 500 per mm3, the increased lactate, or decreased glucose level, strongly supported the diagnosis of SBP. In cases of suspecting SBP but with low PMN count the ascitic values of lactate, glucose and pH will guide the diagnosis. If the ascitic lactate plus glucose, or lactate plus pH are above the cut off levels (lactate > 25 mg/dl; glucose < 60 mg/dl and pH < 7.35) the diagnosis is strongly suggestive. The ascitic fluid pH and A-AF pH gradient were not of diagnostic value due to instability of pH after tapping. For other chemistry in the ascitic fluid, there was a slight increase in ADA level in SBP, but for glucose, protein and glutamine levels, there was no difference among the groups with and without SBP.