Cardiopulmonary Circuits in the Pediatric Population

The goal of this study is to compare the PC/SMART and PMEA treated circuits against each other and the current clinical standard (untreated) circuit with regard to blood component damage during CPB. Specific Aims SA1: To determine if the surface modified circuits decrease platelet activation, platelet sequestration, and fibrinolysis during pediatric cardiac surgery using CPB. Hypothesis 1: Use of a surface modified circuit will attenuate the CPB related decrease in platelet count, diminish platelet dysfunction as measured by thromboelastography (TEG), and decrease fibrinolysis as measured by fibrin-split product levels and TEG. SA2: To determine whether the use of surface modified circuits during pediatric cardiac surgery results in a clinically relevant decrease in post-operative coagulopathy as measured by post-operative bleeding and blood product use. Hypothesis 2: The use of surface modified circuits will result in improved function of the coagulation system yielding less post-operative bleeding and thus fewer blood product transfusions. Methods The study will be a prospective, randomized trial in which a total of 90 patients (5-10 kgs) undergoing first time cardiac surgery using CPB at Egleston Hospital will be randomized into 3 groups. Group 1 will be the control group for whom the current standard unmodified CPB circuit will be used. Group 2 will undergo surgery using the PC/SMART modified CPB circuit (Cobe Cardiovascular Inc, Arvada, CO). Group 3 will undergo surgery using the PMEA modified circuit (Terumo Corporation, Tokyo, Japan). Hypothesis 1 will be tested using the following assays: Total platelet count Hematocrit Prothrombin time (PT) Activated thromboplastin time (aPTT) Fibrin split-product level D-dimer level thromboglobulin level (ELISA assay) Thromboelastography (TEG) using heparinase (to eliminate heparin effect) both with and without REOPRO (a GPIIb/IIIa platelet inhibitor) to measure the relative contributions of platelet function and fibrinogen activity to clot formation Performed at the following time-points: T1 = after induction of anesthesia, prior to CPB T2 = 5 minutes after the initiation of CPB T3 = at the end of re-warming (end of CPB) T4 = post-bypass (five minutes after protamine administration) T5 = within 24 hours after surgery (TEG will not be collected at this time) Hypothesis 2 will be tested by quantifying chest-tube drainage and blood product administration (red blood cells, platelets, fresh frozen plasma, and cryoprecipitate) over the first 12 hours after weaning off of CPB.