Comparison of three plasma expanders used as priming fluids in cardiopulmonary bypass patients

Ten per cent low molecular weight hydroxyethyl starch is a plasma substitute only recently used as priming solution in an extracorporeal circuit, in contrast to human albumin and gelatin. To evaluate the effect of priming solutions on haemodynamics and colloid osmotic pressure, we studied 36 patients elected for cardiopulmonary bypass (CPB). They were randomly assigned to 2.5% hydroxyethyl starch, 3% gelatin or 4% human albumin priming solution. Total blood loss (perioperative + intensive care unit period) was higher in the gelatin group than in the albumin and hydroxyethyl starch groups. During CPB, the colloid osmotic pressure was best preserved in the gelatin group, although no excessively low colloid osmotic pressures were measured in the other two groups. Due to the extended half-life and the additional postoperative colloid administration, the hydroxyethyl starch group had a higher colloid osmotic pressure in the postoperative phase. We conclude that, next to human albumin, 2.5% hydroxyethyl starch is a safe CPB priming solution additive and is effective as plasma substitute. Its somewhat longer half-life requires adaptation of the routine protocol for transfusion of colloids and blood products.