Optimal Protamine Dosing for Heparin Reversal Following Cardiopulmonary Bypass

Inclusion Criteria: * Patients greater than or equal to 18 years of age undergoing elective cardiac surgery with cardiopulmonary bypass. * Patients must that have a calculated protamine dose greater than 250 mg based on standard 1:1 initial heparin to protamine dosing calculation. Exclusion Criteria: * Patients who are under 18 years of age or pregnant. * Patients undergoing emergency surgery (ASA class E). * Patients with known coagulation disorders. * Patients requiring circulatory arrest or deep hypothermia. * Patients who have not had the appropriate interruption in coumadin, direct oral anticoagulants or non-aspirin antiplatelet agents. * Patients on pre-operative intravenous unfractionated heparin infusions. * Patients ineligible for heparin administration due to known adverse reactions including allergy or heparin induced thrombocytopenia or known heparin resistance. * Patients who are unable to provide informed consent in the form of a signature. * History of adverse reaction to protamine. * Have any condition that, in the opinion of the investigator, will compromise the well-being of the patient or the study, or prevent the patient from meeting or performing study requirements.