Influence of hemodilution of plasma proteins on erythrocyte aggregability: An in vivo study in patients undergoing cardiopulmonary bypass

Erythrocyte aggregation is known to be affected by a number of factors including the concentration of various plasma proteins. This study was performed to examine the in vivo effect of hemodilution of plasma proteins on erythrocyte aggregation in patients undergoing cardiopulmonary bypass (CPB) surgery. Blood samples were taken before, during, and after operation from 40 coronary artery bypass grafting patients who were operated with CPB and concomitant hemodilution (CPB, n=20) and who without (nonCPB, n=20). Erythrocyte aggregation was determined with a LORCA aggregometer, during which all samples were standardized to a hematocrit level of 40%. Results showed that in the CPB patients the aggregation index (AI) dropped to 44% of its preoperative baseline level 5 minutes after the start of hemodilution (from 47.7 +/- 10.1 to 26.6 +/- 11.4, p