Diagnostic Sensitivity and Specificity of Serum Ascites Albumin Gradient (Saag) in Patients With Ascites

Objective: to determine the sensitivity and specificity of saag in predicting the presence of esophageal varices and to find out the association between level of saag and increase in portal vein diameter. study design: prospective-observational study. place and duration of study: medical unit iii, jpmc karachi from august 1999 to march 2000. patients and methods: patients with ascites were selected on the basis of selection criteria demonstrated by history, physical examination and ultrasonography. ascitic fluid aspirated for dr and albumin, and simultaneously blood sample taken for total protein and albumin estimation at the time of paracentasis. after determining the level of saag upper gi endoscopy was performed. to determine the cause of ascites detailed history was taken and relevant investigations were carried out. at the end of our study sensitivity and specificity of serum ascites albumin gradient were determined in comparison of endoscopy findings. results: among 50 subjects saag more than 1.1-g/dl was found in 30 (60%) patients and less than 1.1-g/dl in 20 patients (40%) of total 50 patients. out of 30 patients with gradient more than 1.1-g/dl oesophageal varices present in 27 patients and portal vein diameter more than 1.3-cm present in 24 patients. the commonest cause of ascites among subjects with saag more than 1.1-g/dl was chronic liver disease with portal hypertension and the commonest cause of ascites among saag less than 1.1-g/dl was abdominal tuberculosis. the sensitivity and specificity of saag were 100% and 87.8% respectively. conclusion: serum ascites albumin gradient is a reliable marker to differentiate ascites into portal hypertensive and non-portal hypertensive etiology. based upon our finding we conclude that the presence of oesophageal varices is significantly associated with high saag levels.