Prophylactic platelet administration during massive transfusion. A prospective, randomized, double-blind clinical study.

Prior studies at Harborview Medical Center have suggested that dilutional thrombocytopenia is a major etiology of microvascular, nonmechanical bleeding (MVB). We undertook a prospective randomized double-blind clinical study to compare the prophylactic effects of 6 units of platelet concentrates (PLT) versus 2 units of fresh frozen plasma (FFP) administered with every 12 units of modified whole blood in patients undergoing massive transfusion (12 or more units in 12 hours). After exclusions, three of 17 patients who received PLT and three of 16 patients who received FFP developed MVB, an incidence no different from our previous findings. Regression lines of platelet counts during transfusion were no different between groups, and both groups had higher platelet counts than predicted from a standard washout equation. Only one patient had evidence of dilutional thrombocytopenia as a cause for MVB. Prophylactic platelet administration is not warranted as a routine measure to prevent MVB.