A serum ascites-albumin gradient >1.1 g/dL typically indicates ascites caused by which condition?

A serum ascites-albumin gradient (SAAG) greater than 1.1 g/dL is indicative of portal hypertension, which is commonly associated with conditions like cirrhosis. The SAAG is calculated by taking the serum albumin concentration and subtracting the ascitic fluid albumin concentration. A gradient above 1.1 g/dL suggests that the ascitic fluid is due to an increased hydrostatic pressure in the circulation often seen in cirrhosis and congestive heart failure.

Cirrhosis, which can arise from chronic alcohol use, viral hepatitis, or nonalcoholic fatty liver disease, leads to an increase in portal pressure, resulting in the accumulation of fluid in the abdominal cavity. Therefore, a SAAG greater than 1.1 g/dL typically points towards cirrhosis as the underlying cause of the ascites.

Other conditions such as malignancy, pancreatitis, and tuberculosis generally create ascitic fluid with a lower SAAG value when they are the primary causes of ascites, often resulting in gradient values less than 1.1 g/dL. This delineation is crucial for diagnosing and managing patients with ascites, highlighting the importance of evaluating the SAAG in clinical practice.