Platelet support for cardiopulmonary bypass surgery.

After we discontinued the use of fresh blood for cardiopulmonary bypass surgery, we routinely provided platelet concentrates for the patients. To ascertain if this was necessary, patients paired for procedure and age were given either 4 units of platelets (Group I) or no platelets (Group II). Platelet counts were obtained preoperatively; hourly during bypass; immediately, 1/2 hour, and 3 to 4 hours after bypass; and daily for 7 postoperative days. In the 60 patients evaluated, a significant difference between mean platelet counts could not be demonstrated at any time. Total blood use and the total time required for postbypass hemostasis was not significantly different between the two groups. The degree of thrombocytopenia could not be correlated by bypass time. Platelet concentrates or fresh blood are not needed prophylactically for cardiopulmonary bypass surgery, and their usage should be reserved for the occasional patient who manifests thrombocytopenia as well as hemorrhagic complications.