The need for reappraisal of the albumin molecule

Albumin is the protein in the blood with the largest concentration. It is easy to measure, purify, and give to patients. Until recently, there has been little research on its role in the critically ill. Serum concentrations decrease rapidly with illness. Although it has several functions in healthy humans (maintenance of colloid oncotic pressure, drug transport, and free radical scavenging), how these functions change with illness is unknown. Indeed, how albumin itself changes is also unknown. To add to these difficulties in understanding the role of albumin there are relatively normal humans and also rats that lack the genes to make albumin in significant amounts. As well as the expected effects of albumin there are important other effects on blood clotting and the effects of diuretics that need to be evaluated.