1. Transfusion in Cardiopulmonary Bypass

2. Blood Use & Cardiac Surgery 1971 – average 8 units RBC per case Late 1980’s – Texas Heart Institute 1.4 units per case, 35% no blood, 31% one unit Jehovah’s Witness series (N=36) - no blood given, blood loss 200-1200 cc, hgb 14.9-11.2 post op, to hgb 9.2 at lowest point post op day 6

4. Why Reduced Blood Use? Priming pump with electrolyte solution instead of whole blood or PRBC Improved surgical technique Better anesthesia, control of BP Use of inhibitors of fibrinolysis* Re-transfusion of shed blood/cellsaver Tolerance of lower intra-, post-op hgb Hemodilution, autologous donation

5. Why do CABG patients bleed so much? Aspirin, plavix (clopidogrel) Heparin Exposure of blood to non-endothelialized surfaces Shear forces in pump HemodilutionHypothermia Systemic inflammatory response

6. What is Excess Bleeding? Bleeding usually occurs after coming off pump Surgical vs Microvascular CT output > 100-200 cc/hr 2-5% re-operation rate

8. Edmunds L. N Engl J Med 2004;351:1603-1606 Initial Interactions between Plasma Proteins and Biomaterials

9. Diagnostic Tools PT/PTT, platelet count, fibrinogen –Often not well correlated with bleeding –TAT to slow to make decisions in OR Activated Clotting Time (ACT) –Used to titrate heparin, no diagnostic value Thromboelastography –Tricky to interpret and run –Info re fibrinolysis

14. Therapy for Microvascular Bleeding Blood Products –Platelets to treat dysfunction/pump defect –Platelets for count < 50-100K –FFP, CRYO, fibrin glue products –RBC hgb < ~8

15. Antifibrinolytics Aprotinin –Plasmin inhibitor, broader serine protease inhibitor Tranexamic acid, aminocaproic acid –Lysine analog

16. Recombinant FVIIa Safety & efficacy under review Exclude surgical cause, heparin Correct deficits in platelets and coagulation factors Persistent, excessive bleeding

17. Schneeweiss S et al. N Engl J Med 2008;358:771-783 Relative Risk of In-Hospital Death in the Aprotinin Group as Compared with the Aminocaproic Acid Group, Based on Multivariate Analyses of the 78,199 Patients in the Primary Study Cohort, According to the Amount of Aprotinin

18. Schneeweiss S et al. N Engl J Med 2008;358:771-783 Relative Risk of In-Hospital Death among the 78,199 Patients Undergoing Coronary- Artery Bypass Grafting (CABG) in the Primary Study Cohort

19. Koch C et al. N Engl J Med 2008;358:1229-1239 Kaplan-Meier Estimates of Survival and Death

20. Koch C et al. N Engl J Med 2008;358:1229-1239 Postoperative Complications, According to the Duration of Blood Storage