Usefulness of ascites/serum lactic dehydrogenase activity ratio in the initial approach to ascites

To investigate the usefulness of ascitic fluid protein and lactic dehydrogenase activity separating uncomplicated portal hypertension related ascites (PHRA) from non PHRA and complicated PHRA, 58 patients with full diagnosis of the cause of ascites were prospectively studied. Ascitic fluid protein led to misclassify 30% of non PHRA and complicated PHRA, and 13% uncomplicated PHRA. Ascites/serum protein ratio did not improve the diagnostic efficacy of ascites protein concentration alone. Lactic dehydrogenase activity classified properly all uncomplicated PHRA but only 64% of non PHRA and complicated PHRA. All PHRA without complications and 92% of non PHRA and PHRA with complications were correctly allocated by ascites/serum dehydrogenase activity ratio. This criteria had higher sensitivity and efficiency than total protein concentration (p < 0.05). Our data suggest that ascites/serum lactic dehydrogenase ratio may offer advantages over ascites total protein concentration discriminating uncomplicated PHRA from non PHRA and PHRA with complications in the initial approach to a peritoneal effusion.