Heparin Reversal With Two Different Protamine Ratios After Cardiopulmonary By-pass.

Protamine is routinely administered as a heparin-reversal factor in cardiac surgery. However, protamine is associated with specific adverse events, while it has additional anticoagulant effect while in excess. The literature supports that a reversal ratio lower than 1mg:100 IU (1:1) of heparin is safe and effective. According to recent studies, a ratio equal to 0.84:1 of initial or 0,6 of total heparin is safe and effective in cardiac surgery. Even lower ratios (<0,5:1) have been studied with positive outcomes.

The aim of this study is to evaluate the effectiveness of heparin reversal with two different protamin ratios (0,6:1 και 0,8:1) regarding the Activated Clotting Time (ACT), viscoelastic tests (Clot-Pro) and clinical hemorrhage.

Methods Perioperative management will follow standard department practice. The patients will be randomized to receive an initial dosage of protamine in a ratio 0.8 or 0.6 to 1 of the total heparin post cardiopulmonary by-pass disengagement. ACT and Clot Pro tests (IN, HI, EX and FIB-test) will run. In case of ongoing clinical hemorrhage, coagulation factors will administrated according to Clot Pro results, and in case of persistent clinical hemorrhage and any indication of heparin excess in the measured values, another 25mg of protamine will be administrated, while tests will be repeated. All patients will sign an informed consent prior to their inclusion in the study.

Data collection During pre-operative evaluation, age, weight, height, sex, BSA, ASA classification, Euroscore II, medication and co-morbidities will be documented.

Intraoperatively, anesthesia, cardiopulmonary bypass and aortic cross clamping time will be documented, as well as drugs administered and related adverse events.