Hemolysis during cardiopulmonary bypass.

Hemolysis of red blood cells is a problem during cardiopulmonary bypass. The present study was undertaken to evaluate the influence of the priming solution and of the initial acceleration of the pump on red blood cell trauma and hemolysis. Eighty adult patients undergoing coronary artery grafting with cardiopulmonary bypass (CPB) were randomly assigned to one of four groups according to the nature of the priming solution and the initial speed of CPB flow (time from the start to the full calculated flow): group 1, lactated Ringer's (LR) with 5% dextrose (5%D), 1 minute; group 2, LR5%D, 2 minutes; group 3, LR, 1 minute; group 4, LR, 2 minutes. Plasma hemoglobin was found to be 4 times higher in group 1 than in the three other groups (P less than 0.001). It is concluded that there is an interaction between the presence of glucose in the priming solution and the initial acceleration of pump flow. The combination of LR5%D prime with a short time interval to full pump flow leads to a significant degree of hemolysis.