Serum and ascites albumin gradient (SAAG)

是評估ascites病患的一個工具..

一般而言以1.1 g/dl作為分界..

若SAAG >1.1 g/dl:

- cirrhosis (spontaneous bacterial peritonitis)
- acute hepatitis
- extensive malignancy (HCC or metastasis)
- right-sided heart failure
- Budd-Chiari syndrome, hepatic veno-occulsive disease
- portal or splenic vein thrombosis

若SAAG <1.1 g/dl

- TB peritonitis
- peritoneal carcinomatosis
- vascularitis (again?)
- nephrotic syndrome, protein-loss enteropathy
- Meigs' syndrome (triad of ovarian tumor, pleural effusion, and ascites)

若SAAG >1.1 g/dl,要進一步區分cardiac causes或是non-cardiac causes..除了病史之外,可以評估ascites fluid total protein (AFTP)..

若AFTP >2.5 g/dl: cardiac causes
若AFTP <2.5 g/dl: non-cardiac causes

Adapted from N Engl J Med. 2006; 354: 2166-75.