Objective: To determine if the platelet glass bead retention assay can predict bleeding after cardiac surgery.
Design: Prospective, observational study.
Setting: Large, tertiary care, academic medical center.
Participants: Forty-three adult patients scheduled to undergo elective cardiac surgery employing cardiopulmonary bypass (CPB).
Measurements and main results: Whole blood samples were observed for platelet count, prothrombin time, and platelet (glass bead) retention assay. The platelet retention and prothrombin times were independent univariant and multivariant predictors of bleeding after CPB (r = 0.554, p = 0.0002 and r = 0.655, p = 0.00001).
Conclusion: The platelet glass bead retention assay measures dynamic platelet function and is sensitive to the CPB-induced adhesion and aggregation defect and correlates with postoperative blood loss. Modification of this platelet function assay used with the prothrombin time may provide a simple and effective diagnostic approach to bleeding after CPB.