Differential diagnosis of ascitic fluid: evaluation and comparison of various biochemical criteria with a special reference to serum ascites albumin concentration gradient and its relation to portal pressure.

Among various biochemical indices measured in 93 patients with ascites, ascitic LDH estimation was proved to be indiscreminatory, while ascites/serum LDH ratio has shown a diagnostic accuracy of 85 per cent. Ascitic total protein levels and ascites/serum total protein ratio (accuracy rates of 72 and 77% respectively) were limited, especially in differentiating the ascites due to heart failure. Serum ascites albumin gradient, showed a strong correlation to portal pressure (r, + 0.83 + 0.88), and was found to be the best diagnostic index (with an overall accuracy of 97 per cent) in distinguishing the 'transudative' from 'exudative' ascites. However, no index could discreminate the 'mixed' cases and provide the etiological diagnosis of the ascites.