Human serum albumin (HSA) has been used for a long time as a resuscitation fluid in critically ill patients. It is known to exert several important physiological and pharmacological functions. Among them, the antioxidant properties seem to be of paramount importance as they may be implied in the potential beneficial effects that have been observed in the critical care and hepatological settings. The specific antioxidant functions of the protein are closely related to its structure. Indeed, they are due to its multiple ligand-binding capacities and free radical-trapping properties. The HSA molecule can undergo various structural changes modifying its conformation and hence its binding properties and redox state. Such chemical modifications can occur during bioprocesses and storage conditions of the commercial HSA solutions, resulting in heterogeneous solutions for infusion. In this review, we explore the mechanisms that are responsible for the specific antioxidant properties of HSA in its native form, chemically modified forms, and commercial formulations. To conclude, we discuss the implication of this recent literature for future clinical trials using albumin as a drug and for elucidating the effects of HSA infusion in critically ill patients.
Albumin solutions have been used worldwide for the treatment of critically ill patients since they became commercially available in the 1940s. However, their use has become the subject of criticism and debate in more recent years. Importantly, all fluid solutions have potential benefits and drawbacks. Large multicenter randomized studies have provided valuable data regarding the safety of albumin solutions, and have begun to clarify which groups of patients are most likely to benefit from their use. However, many questions remain related to where exactly albumin fits within our fluid choices. Here, we briefly summarize some of the physiology and history of albumin use in intensive care before offering some evidence-based guidance for albumin use in critically ill patients.