Blood Day: The Role of the Anesthesiologist/Perioperative Physician

1. Blood Day: The Role of the Anesthesiologist/Perioperative Physician Scott Wolfe, MD, FRCPC Department of Anesthesia and Perioperative Medicine University of Manitoba

2. Blood Day 2011 • Part 1: Transfusion Considerations • Complications of transfusion • Transfusions and outcomes • When to transfuse (transfusion triggers)

3. Blood Day 2011 • Part 2: Case Discussion- (Application Blood Conservation Strategies) • Correction of anemia preoperatively • Iron/Epo • PAD • Cell salvage • ANH/Hypovolemic sequestration • Tranexamic acid • Regional Data- WRHA Blood Conservation Program

4. 3rd edition 2011

5. PART 1 Transfusion Considerations • Provide a framework of concepts which translate in the pattern of practice seen in perioperative transfusion medicine

6. The potential hazards of Transfusion • Acute hemolytic transfusion reaction • ABO mismatch/incompatibility • TRALI- transfusion related acute lung injury • TACO- transfusion associated circulatory overload • Anaphylaxis • Infectious- HIV, Hep C, bacterial, unknown/untested pathogens

7. Transfusion-Related Fatalities in the United States, 2004-2006 American Blood Center Newsletter, 2007

8. Complications of Transfusion • Changes in Oxygen Transport of RBC • Impaired from preservation process and age of blood • Difficult to release O2 to tissues immediately after transfusion • Coagulopathy (from Massive Transfusion) • Dilutional thrombocytopenia +/or coagulation factors • Disseminated Intravascular Coagulation • Hypothermia • Electrolyte abnormalities (hyperkalemia, hypocalcemia) • Acid-Base abnormalities (pH 6.7-6.9, citratebicarbonate)

9. Other associated conditions/outcomes from transfusion • Immunomodulating effects • Increased risk of nosocomial infections • Acute lung injury • Development of autoimmune diseases later in life • Recurrence of malignancy • Length of hospital stay

11. Transfusion trigger • Threshold or lower limit when to transfuse patients • Studies have led to guidelines established on transfusion triggers for given patient populations • Shown equal if not improved outcomes in the restricted transfusion practice versus the more liberal transfusion groups

14. Massive transfusion and coagulopathy: pathophysiology and implications for clinical management. Hardy JF et al. CJA 2006

15. So What Does This Mean to the perioperative health care team? • Reasonable data to avoid if possible the use of blood products • In General, we can adapt lower limit for transfusion than in the past • These two conclusions have made “Blood Conservation Strategies” more attractive in the last decade

16. PART 2 • Case presentation • Application of perioperative blood conservation strategies

17. Case: Mr. X • 50 yo male • PMhx • Spinal Stenosis, Anemia Hbg 100g/l, low Fe stores • Rest of history and labs are normal • Wt 70 kg • Scheduled for a multilevel spine instrumentation and fusion booked for 8 hours • Estimated Blood Loss range 1000-3000ml

18. Preoperative period • Allows for optimization of patients health status and correction of anemia • Maximum blood loss calculation (MABL): • MABL= (starting Hb- transfusion trigger) x pt blood volume starting Hgb • For Hbg 100 could lose 1400 ml’s before trigger Hgb of 70 • For Hgb 140 could lose 2400 ml’s before trigger Hbg 70

19. Optimizing Preoperative Hbg:

22. Preoperative anemia • IV or oral Iron therapy

23. I.V. Iron TherapyIndications When oral Fe not tolerated Urgent pre-op correction of anemia Low hgb when transfusion may be imminent

24. IV Iron Therapy

25. Erythropoetin (EPO) • Hormone that regulates red blood cell production • Perioperative Indications: • Anemia of chronic disease (including renal disease) • Adjunct to iron therapy • When there is limited endogenous production (hgb 105-120) • Occasionally adjunct to PAD • Usually given weekly for 2-3 weeks preoperatively • FDA cautions in patients with Cancer

26. Erythropoietin therapy 2010

27. Preoperative autologous blood donation (PAD): • Institution dependent across Canada • Winnipeg • reserved for revision Orthopedic (hip) surgery, • patients with rare blood types, • Benefits: ?possibly reduces post op infections • Reduces demand on allogenic blood supplies • Reduces transmission of some infections • Prevents some adverse transfusion reactions

28. Preoperative autologous blood donation (PAD) Risks: Donation: • 12 fold higher risk of severe reaction at time on donation • Lost unit • Cancelled OR and outdated autologous unit Transfusion • Bacterial contamination • ABO mismatch (wrong blood given) • Transfusion of allogenic blood when autologous available Overall reduces chance of allogenic transfusion but increases likelihod of all transfusion, NOT been shown to be safer… Poor Cost-effectiveness

29. Mr.X: The Day of Surgery • Preop: • Investigated anemia • Gave IV iron sucrose x 2 doses • Hbg 140 • Now the day of the OR • What can we do?

30. Mr. X: Intraop • Surgical technique • ANH • Cell Salvage • Antifibrinolytics

31. Acute NormovolemicHemodilution

32. ANH for Mr. X • Starting Hgb 140 g/l • No ANH: if loses 1000ml  140 g’s of Hb lost • Undergo ANH to starting hgb of 100 • If loses 1000ml  100 g’s of Hb lost • End of case the whole blood taken off at beginning given back • Both augmenting Hgb conc. and fresh supply of coagulation factors and platelets • Very little data on the efficacy and safety of ANH and its widespread use at this time cannot be recommended. • (ASA I and Jehovah’s Witnesses)

33. Cell salvage

34. Intraoperative cell salvage. Kuppurao L , Wee M Contin Educ Anaesth Crit Care Pain 2010;10:104-108

35. ‘Hypovolemic sequestration’ • Variant of ANH and cell salvage • Slight reduction in circulating volume ‘hypovolemia’ • Intermediary Hgb 140125 • Higher hgb thought to increase yield from cell salvage • Retain benefits of fresh supply of Hgb, plt and coag factors at end of the case

36. Tranexamic acid • An Antifibrinolytic that inhibits degradation of the fibrin, basic framework for formation of a clot  clot stabilizer • Hemostatic effects have been shown to reduce blood loss in orthopedic, hepatic and cardiac (Cochrane review Henry et al.) • Also shown to decrease mortality in trauma patients with mild to moderate bleeding given within the first 3 hours • Variable dosing in literature • 15-30mg/kg usual dose (+/- repeat in 6-8 hours) • Relatively safe, side effects  GI upset, seizures • Relative Contraindications: patients at elevated risk for thrombosis Henry DA et al. Anti- fibrinolytic use for minimising perioperative allogeneic blood transfusion. [Systematic Review] Cochrane Injuries Group Cochrane Database of Systematic Reviews. 2011

37. Case Summary: Mr X OPTION 1 Standard  Preop Hgb 100  Intraop 1.5 l blood loss  Postop Hgb 70 OPTION 2 BLOOD CONSERVATION  Preop hgb 140 with IV Fe  Intraop Cellsaver, ANH 1.5 l blood loss  Postop Hgb 100

38. Conclusion • Further studies show more restrictive transfusion practice improves outcomes • Known risks of transfusion • Limited blood supply • Current information locally via database  warrants further research oppurtunities • Blood conservation strategies will have a larger and larger role in perioperative medicine.

39. The Ten Commandments of TransfusionQUESTIONS?‘Bloody Easy 3’ JL Callum et al. 2011