Hypoalbuminemia, or an abnormally low level of albumin in the blood, is a common condition in patients with serious illness and is correlated with increased morbidity and mortality, and prolonged stays in hospitals and intensive care units (ICUs). The relationship between hypoalbuminemia and poor outcomes has motivated many physicians to administer exogenous albumin to hypoalbuminemic patients; however, there is insufficient evidence to support the efficacy of this practice. Vincent and colleagues performed a systematic review of cohort studies with serum albumin level as an outcome predictor in acutely ill patients and controlled trials that focused on the correction of hypoalbuminemia.
The meta-analysis found that the odds of death were increased by 137 percent with each decline of 10 g per L in the serum albumin level. Hypoalbuminemia was also a significant predictor of increased morbidity, increased length of ICU and hospital stays, and increased use of resources during the period of acute care. Malnutrition and inflammation did not fully explain the hypoalbuminemic effects.
Nine prospective controlled studies evaluated the administration of supplemental albumin to acutely ill patients who had hypoalbuminemia (n = 535). The odds ratio for complications declined progressively with increases in the attained serum albumin level. Based on these results, the authors conclude that attaining a serum albumin level higher than 3 g per dL (30 g per L) probably lessens morbidity. The protective effects of albumin may be explained by the maintenance of physiologic homeostasis, including maintenance of normal colloid osmotic pressure. Other possible positive effects of albumin include its antioxidant properties, capacity to prevent apoptosis, and affinity to bind lipids, drugs, and toxic substances.
The authors conclude that albumin-replacement therapy may be clinically appropriate in patients with hypoalbuminemia, although well-designed controlled clinical trials are needed to confirm benefit.
editor's note: The administration of albumin to patients with hypoalbuminemia remains controversial. Alderson and associates1 specifically reviewed the usefulness of albumin administration in critically ill patients with hypovolemia, burns, or hypoalbuminemia. In this meta-analysis of randomized controlled trials in which varying volumes and concentrations of albumin were administered and compared with administration of a crystalloid solution, albumin administration was associated with increased mortality. These results are in contrast to those noted in the article by Vincent and colleagues and in a review performed by Wilkes and Navickis,2 who examined randomized controlled trials of albumin administration in a broader population of patients. In this analysis, there was no association between albumin administration and an increased risk of death compared with patients who received crystalloid therapy, no albumin, or lower dosages of albumin. However, further review of the analysis by Wilkes and Navickis demonstrates a trend toward harm associated with some of the subgroups studied. Further study is needed to identify patient subgroups who may benefit from albumin administration and those who may be harmed.—r.s.