Plasma disappearance rate of albumin when infused as a 20% solution

Abstract

Background The transcapillary leakage of albumin is increased by inflammation and major surgery, but whether exogenous albumin also disappears faster is unclear. Methods An intravenous infusion of 3 mL/kg of 20% albumin was given over 30 min to 70 subjects consisting of 15 healthy volunteers, 15 post-burn patients, 15 patients who underwent surgery with minor bleeding, 10 who underwent surgery with major bleeding (mean, 1.1 L) and 15 postoperative patients. Blood Hb and plasma albumin were measured on 15 occasions over 5 h. The rate of albumin disappearance from the plasma was quantitated with population kinetic methodology and reported as the half-life (T1/2). Results No differences were observed for T1/2 between volunteers, post-burn patients, patients who underwent surgery with minor bleeding and postoperative patients. The T1/2 averaged 16.2 h, which corresponds to 3.8% of the amount infused per h. Two groups showed plasma concentrations of C-reactive protein of approximately 60 mg/L and still had a similarly long T1/2 for albumin. By contrast, patients undergoing surgery associated with major hemorrhage had a shorter T1/2, corresponding to 15% of the infused albumin per h. In addition, our analyses show that the T1/2 differ greatly depending on whether the calculations consider plasma volume changes and blood losses. Conclusion The disappearance rate of the albumin in 20% preparations was low in volunteers, in patients with moderately severe inflammation, and in postoperative patients.

The glycocalyx as a permeability barrier: basic science and clinical evidence

“…If the glycocalyx functions as a permeability barrier, the intravascular half-life of exogenous albumin contained in an infusion of 20% albumin would be expected to be shortened by surgery and inflammation. However, postoperative patients and post-burn patients with moderately severe inflammation (plasma C-reactive protein of 60–80 mg/L) and patients undergoing surgery with minor hemorrhage had the same intravascular half-life of exogenous albumin when compared with healthy volunteers [ 55 ]. The post-burn patients given 20% albumin even showed a normal capillary leakage of albumin and fluid despite major elevations, even up to 100-fold, of plasma syndecan-1 [ 56 ].…”

“…The use albumin as biomarker of capillary leakage is prone to errors in complex clinical situations [55], but a large body of evidence supports that both glycocalyx degradation products [59] and capillary leakage of albumin and fluid [60,61] are increased in septic patients. Fleck et al even reported quadrupled capillary leakage rates in patients with septic shock [62].…”