Plasma clearance and renal excretion of erythrocyte cryoprotectant hydroxyethylated amylopectin

The value of low molecular weight-hydroxyethylated amylopectin (cryo-HES) as an extracellular cryoprotectant has been demonstrated in vitro. It is important that details of the intravascular persistence and urinary excretion be determined to compare with data already available as other grades of HES and with data on transfusion of cryo-HES cryoprotected blood. Following a single 400 ml (14% solution) infusion in man, the intravascular clearance of cryo-HES was well described mathematically by the equation: y = 3.30+6.49e-0.15kappa. The plasma concentration of cryo-HES fell to half its peak value in approximately 9.6 h. Approximately 20% of the total infused cryo-HES was excreted in the urine during the first post-injection hour, and 50% by 72 h. The ESR was not altered significantly by the presence of this material. The present study indicates that cryo-HES is eliminated rapidly and may thus be safe for transfusion to recipients of frozen blood.