The Case for Albumin as Volume Expander and beyond

Abstract

AbstractThis chapter discusses the importance of endogenous albumin, the most abundant plasma protein in the body. Albumin has diverse functions such as antioxidant, anti-inflammatory activities, intravascular buffering, drug metabolism, transport, distribution, and restoration of vascular endothelial integrity. It is also crucial for maintaining the endothelial glycocalyx layer in blood vessels. Critically ill patients may experience hypoalbuminemia, defined as serum albumin <35 g/L, due to reduced synthesis, malnutrition, increased loss, or increased catabolism. Observational studies show hypoalbuminemia as an independent predictor of worse outcomes, with a 10 g/L decrease in serum albumin linked to a higher risk of mortality, morbidity, longer ICU/hospital stays, and increased resource utilisation. Administering exogenous albumin targeting serum albumin >30 g/L may reduce complications, but further trials are needed. Exogenous albumin is used in the ICU for various indications, including resuscitation and deresuscitation. Evidence on its use as a plasma expander is inconclusive. Both high- (20%) and low-concentration (4 and 5%) albumin can be used for resuscitation if patients require additional fluid, despite receiving crystalloids. Albumin is safe and effective for plasma expansion in patients with sepsis and septic shock but should be avoided in traumatic brain injury. Judicious and vigilant use of albumin is recommended due to its cost and potential risks. Albumin administration should be based on clinical indications, and monitoring fluid balance and clinical parameters is critical to prevent fluid accumulation and oedema formation.