Effects of albumin supplementation on microvascular permeability in septic patients.

Albumin has a stabilizing effect on endothelium and helps maintain capillary permeability to macromolecules. Critically ill patients with sepsis may have profound hypoalbuminemia, but the effect of this hypoalbuminemia on microvascular permeability is unknown. To determine the degree and potential importance of this effect, we measured the transcapillary escape rate (TER) of (125)I-labeled albumin in 12 adult patients fulfilling American College of Chest Physicians/Society of Critical Care Medicine criteria for septic shock. We measured TER over a 90-min baseline period and then repeated these measurements immediately after the rapid infusion of 200 ml of 20% albumin. At baseline, patients had a mean serum albumin concentration of 10.3 +/- 3.8 g/l, which, at 30 min after the albumin infusion, was 18.5 +/- 3.7 g/l. The baseline TER was 6.7 +/- 1.5%/h, with a postinfusion TER of 6.4 +/- 2.1%/h (P = 0.550). Albumin supplementation sufficient to nearly double serum concentrations in profoundly hypoalbuminemic septic patients had no clinically significant effect in reducing microvascular permeability.