DIAGNOSING ASCITIC ETIOLOGY ON A BIOCHEMICAL BASIS

BACKGROUND/AIMS: The analysis of ascitic fluid has been complicated by several new tests. To simplify its assessment, we evaluated ascitic f luid pH with six other parameters prospectively and simultaneously in blood and ascitic fluid in sixty patients with ascites. METHODOLOGY: S ixty patients were selected on whom abdominal paracentesis was perform ed in order to determine which tests were the most reliable for the et iological diagnosis of ascites. Their ascitic fluid pH, cholesterol, a lbumin, and total proteins were analyzed to distinguish between malign ant and cirrhotic ascites. The diagnosis of cirrhosis was based on his tological findings, and/or clinical, biochemical, and endoscopic/ultra sonographic findings in whom percutaneous liver biopsy was contraindic ated. RESULTS: The serum-ascites albumin gradient was higher (p<0.001) in cirrhotic as compared to tubercular, malignant or cardiac ascites. We discovered that ascitic fluid lactate dehydrogenase and cholestero l were best for diagnosing malignant ascites, ascitic fluid glucose an d ascitic fluid/blood glucose ratio were perfect for diagnosing tuberc ular ascites, and ascitic fluid pH and lactate dehydrogenase were suit able for diagnosing spontaneous bacterial peritonitis. Correspondingly , ascitic fluid albumin, ascitic fluid/serum albumin, total proteins, and serum ascites albumin gradient were best for diagnosing sterile ci rrhotic ascites. CONCLUSIONS: Diagnostic paracentesis is a useful proc edure. The practice of ordering a battery of tests on every ascitic fl uid specimen should be abandoned. Rather, an algorithm approach should be adopted in which the results of initial analysis guide us to furth er relent tests that help in arriving at the etiology of ascitis.