Effects of desmopressin acetate on platelet aggregation, von Willebrand factor, and blood loss after cardiac surgery with extracorporeal circulation.

The effects of desmopressin acetate (DDAVP) on platelet aggregation and the von Willebrand factor antigen (vWF:Ag) were studied in 19 patients undergoing cardiac surgery with extracorporeal circulation. The patients represented one of five blocks in a randomized double-blind placebo-controlled parallel group trial on the effects of DDAVP on postoperative bleeding after uncomplicated coronary artery bypass operations. After termination of extra-corporeal circulation, DDAVP (0.3 microgram/kg body wt) or its vehicle was infused into a peripheral vein throughout 15 minutes. The increase in factor VIII coagulant activity after infusion did not differ between the groups but there was a significantly larger increase in vWF:Ag levels in DDAVP-treated patients. The aggregatory response to adenosine-diphosphate (ADP) and ristocetin showed a normal pattern and was not significantly different between the two groups. As compared with placebo, DDAVP did not decrease the bleeding time or the postoperative blood loss. We conclude that DDAVP causes an increase in vWF:Ag levels but does not alter platelet aggregation, bleeding time, or blood loss in uncomplicated coronary artery bypass patients.