Serum Ascites Albumin Gradient (SAAG)

Why Use

Obtaining ascites fluid is relatively simple and safe in experienced operators. The constituents of ascites fluid offer a less-invasive method for gauging risk and portal hypertension status.

When to Use

Patients with known liver disease and ascites in whom portal hypertension status is unknown.

Formula

Pearls / Pitfalls

The serum ascites albumin gradient (SAAG) can determine which patients with liver disease have portal hypertension. A cutoff level of 1.1 has been validated to determine who has portal hypertension.

Management

We are unaware of validated management algorithms using the SAAG.

Critical Actions

The SAAG requires temporally similar blood and ascites fluid examinations.

Advice

The SAAG seems reliable and useful for determining portal hypertension. It is not as reliable for making pathologic diagnoses, and its value in settings outside of referral populations with liver failure is unknown. Moreover, prospective data are dominated by one SAAG validation study, suggesting future investigations have the potential to shed further light.

More Information

Interpretation SAAG > 1.1 g/dL indicates portal hypertension is the cause of ascites with 97% accuracy. SAAG scores do not indicate the cause of the portal hypertension.