Protamine Test Dose: Impact on Activated Clotting Time and Circuit Integrity.

Background: Recurrent observation of clot in the cardiopulmonary bypass circuit after the administration of a protamine test dose (PTD) prompted concern over the effects of PTDs on patient activated clotting times (ACTs).

Methods: Data were prospectively collected on 120 patients who had cardiopulmonary bypass while undergoing a variety of cardiac surgical procedures from July to October 2018 at the Toronto General Hospital, Toronto, Canada. ACTs were documented before cardiopulmonary bypass termination, after PTDs, and after protamine full doses.