Strategies for Protamine Dosing After Anticoagulation in Cardiovascular Surgery
Status:
Recruiting
Trial end date:
2021-11-22
Target enrollment:
Participant gender:
Summary
In cardiovascular surgery, patients are anticoagulated with heparin during cardiopulmonary
bypass, subsequently, anticoagulation is reversed with protamine to reduce bleeding due to
residual heparin-induced coagulopathy, which can last more than four hours. Protamine
reverses the effect of heparin by binding to each heparin molecule, therefore an amount of
protamine equivalent to residual heparin is required at the time that anticoagulation is
desired to be reversed, but generally, the dose of protamine is calculated from the total
dose of heparin, ignoring that heparin is metabolized and cleared during of the
extracorporeal circulation, this excess of protamine produces anticoagulant effects that
increase postoperative bleeding. Residual heparin can be estimated from heparin
pharmacokinetic models and therefore, from these models, a dose closer to the amount
necessary to reverse the effect of heparin can be estimated, avoiding protamine excess. In
this study, a protamine dosage strategy based on residual heparin determined by a
pharmacokinetic model of heparin versus total administered heparin will be compared regarding
bleeding and use of blood components in the postoperative period.