Serum-ascites albumin gradient

Overview
The serum-ascites albumin gradient (SAAG) helps determine the cause of ascites. SAAG = albumin concentration of serum - albumin concentration of ascitic fluid

The SAAG is probably a better discriminant than older measures (transudate versus exudate) for the causes of ascites. A high gradient (> 1.1 g/dL) indicates the ascites is due to portal hypertension. A low gradient (< 1.1 g/dL) indicates ascites of non-portal hypertensive etiology.

Important causes of high SAAG ascites (> 11 gm/L) include cirrhosis of the liver, Budd Chiari syndrome and heart failure.