The role of protamine dose assay in reversal of heparin following extracorporeal circulation for open heart surgery.

: The amount of protamine required for the neutralisation of heparin following cardiopulmonary bypass was determined by a Protamine Titration Assay using the principle of the dose--response curve and the patient's estimated blood volume. In 300 open heart surgery patients, infusion of the determined dose of protamine normalised the Activated Clotting Time (ACT) to baseline levels in 97% of these patients and produced adequate hemostasis. Our present study showed that the dose of protamine dropped to 75% of the dose calculated by conventional method of heparin to protamine ratio of 1:1. This had minimised the adverse effects of excessive protamine administration and optimised coagulation control after extracorporeal circulation.