Post Cardiac Surgery Blood Loss: Effect of Washing Residual Cardiopulmonary Bypass Circuit Blood Red Cells Prior to Re-infusion. A Proof of Concept Study

The primary hypothesis of this study is that in our study population, compared to re-infusion of residual CPB blood, re-infusion of only the red cell component of residual CPB blood, causes a lesser defect in clotting, leading to decreased hemorrhage and less post-operative blood loss.

The secondary objectives of this project are to document the effects on the clotting system of pump blood re-infusion by means of in laboratory testing. This work has not been done and is of crucial importance to future optimization of the use of pump blood. We expect to detect and quantify with significant accuracy any increased bleeding risk with our hemostatic profiling. This information will be invaluable in planning the safe introduction of residual CPB blood re-infusion smaller children and those with increase risk of postoperative blood loss. Furthermore, we will determine whether or not any of the potentially beneficial effects to the clotting system of returning all components of residual CPB blood, such as an increase in functioning platelets, or an increase in clotting factors, are realized. This information will determine the utility of pursuing means by which these non red cell components of residual CPB blood can be safely re-infused.

Induction of anesthesia, arterial and venous vascular catheter placement, heparin administration, cardiopulmonary bypass machine setup and priming, conduct of CPB, ultrafiltration of blood during CPB, post-CPB protamine administration and post-CPB blood ultrafiltration will all be standardized as per current clinical practice.

Residual CPB blood will be processed and re-infused according to group allocation.

Intravascular volume in the form of crystalloid, and blood products will be administered over and above the study residual blood product infusion as required according to protocol.