Human albumin solution for patients with cirrhosis and acute on chronic liver failure: Beyond simple volume expansion

Abstract

To provide an overview of the properties of human serum albumin (HSA), and to review the evidence for the use of human albumin solution (HAS) in critical illness, sepsis and cirrhosis. A MEDLINE search was performed using the terms “human albumin”, “critical illness”, “sepsis” and “cirrhosis”. The references of retrieved articles were reviewed manually. Studies published between 1980 and 2014 were selected based on quality criteria. Data extraction was performed by all authors. HSA is the main plasma protein contributing greatly to its oncotic pressure. HSA demonstrates important binding properties for endogenous and exogenous toxins, drugs and drug metabolites that account for its anti-oxidant and anti-inflammatory properties. In disease states, hypoalbuminaemia is secondary to decreased HSA production, increased loss or transcapillary leakage into the interstitial space. HSA function can be also altered in disease with reduced albumin binding capacity and increased production of modified isoforms. HAS has been used as volume expander in critical illness, but received criticism due to cost and concerns regarding safety. More recent studies confirmed the safety of HAS, but failed to show any survival benefit compared to the cheaper crystalloid fluids, therefore limiting its use. On the contrary, in cirrhosis there is robust data to support the efficacy of HAS for the prevention of circulatory dysfunction post-large volume paracentesis and in the context of spontaneous bacterial peritonitis, and for the treatment of hepato-renal syndrome and hypervolaemic hyponatraemia. It is likely that not only the oncotic properties of HAS are beneficial in cirrhosis, but also its functional properties, as HAS replaces the dysfunctional HSA. The role of HAS as the resuscitation fluid of choice in critically ill patients with cirrhosis, beyond the established indications for HAS use, should be addressed in future studies.

Keywords: Human serum albumin, Human albumin solution, Critical illness, Cirrhosis, Resuscitation fluid, Large-volume paracentesis, Hepatorenal syndrome, Spontaneous bacterial peritonitis

Core tip: Human serum albumin has several important functions beyond being the principal protein in plasma. In disease states, albumin levels may not only be low but there may also be functional hypoalbuminaemia. This may explain why human albumin solution is helpful in treating the complications of cirrhosis whereas its role (as a volume expander) in critical illness remains limited. However, in the presence of cirrhosis or acute liver failure the restoration of functional albumin may be beneficial, even in critically ill patients. This still needs to be addressed in clinical trials.