Hypothermic cardiopulmonary bypass results in peripheral vasoconstriction and heparin
trapping. Hypoperfusion and ischemic-reperfusion injury are associated with systemic
inflammatory response, while insufficient and delayed neutralization of heparin by protamine
may contribute to more blood loss during rewarming stage.
Nitroglycerin infusion, an NO-related vasodilator, is an established and effective treatment
for unstable angina, myocardial infarction, congestive heart failure, and perioperative
hemodynamic management for cardiac surgery. Therefore, we hypothesize that nitroglycerin
infusion during rewarming corrects systemic ischemic stress and facilitates heparin
neutralization in cardiac surgery.