The Role of Intravenous Albumin Replacement During Abdominal Paracentesis in Patients With Malignancy Related Ascites

General Introduction:

Therapeutic paracentesis is the first line of treatment for patients with symptomatic malignant ascites. The practice of intravenous albumin infusion during abdominal paracentesis comes from evidence in patients with liver cirrhosis. A meta-analysis of seventeen randomised trials evaluating patients receiving albumin versus alternative treatment during large volume paracentesis found that albumin reduced the incidence of post-paracentesis circulatory dysfunction, hyponatraemia and mortality (Bernardi M, 2012). The mechanisms of ascites in patients with cirrhosis are driven by portal hypertension. Portal hypertension brings about systemic vasodilation and hyperdynamic circulation that eventually contribute to functional and biochemical changes leading to ascites (Gines. P, 1997).

In contrast, cause of ascites in patients with malignancies is usually multi-factorial. It occurs commonly in several tumours including malignancies of ovary, breast, colon, lung, pancreas and liver. In each of these cancer types, the mechanisms leading to malignancy-related ascites may be different. Peritoneal carcinomatosis is a major cause of malignancy-related ascites. Other causes include massive liver metastasis causing portal hypertension, chronic hypoalbuminaemia, hepatocellular carcinoma, chylous ascites from lymphoma and Budd-Chiari syndrome due to occlusion of hepatic veins (Runyon BA, 1988).

In patients with cancer, aside from those who develop ascites as a result of portal hypertension, the benefit of intravenous albumin infusion with large volume paracentesis is uncertain, if at all present. Locally, the current clinical practice is for infusion of intravenous albumin during abdominal paracentesis in patients with malignancy-related ascites regardless of cause. The drawbacks of such an approach include exposing patients to risk of anaphylaxis and increased financial costs (50 ml of 20% Albumin costs $42).

Granted that the potential harms of albumin infusion are rare, the burden of proof to show that an intervention works is held by those who introduce it. To date, there have been no studies specifically examining the role of intravenous albumin infusion in this population. In the setting of advanced cancer where life expectancy is limited, the most clinically relevant benefit of albumin infusion would be to reduce the rates of post-paracentesis circulatory dysfunction. Through a pilot study, we hope to evaluate the effectiveness of IV albumin in reducing rates of hypotension, thereby guiding clinical practice in this area.