Ascites

Ascites is the accumulation of fluid within the peritoneal cavity. Most patients with ascites usually have a known diagnosis of cirrhosis, malignancy, or heart failure. For patients newly presenting with ascites, the diagnostic problem is usually to differentiate between cirrhosis and malignancy. For patients with established liver disease, ascites represents a deterioration of their liver function, the development of a hepatocellular carcinoma, or another complication. Worsening of preexisting ascites may be due to spontaneous bacterial peritonitis. In malignancy, ascites denotes the development of peritoneal deposits or massive liver metastases. The diagnosis may be obvious from the context, but can be confirmed with imaging and a diagnostic paracentesis. The serum–ascites albumin gradient (SAAG) ([ascitic fluid albumin] − [serum albumin]) reflects portal pressure, and is the key diagnostic test. A SAAG >11 g/l indicates portal hypertension, and therefore probable cirrhosis. A SAAG <11 g/l excludes portal hypertension, and therefore the ascites is not caused by cirrhosis.