Transfusions & Surgery

1. Transfusions & Surgery Christopher J. Gresens, M.D. VP & Medical Director, Clinical Services BloodSource

2. Surgical Transfusion Medicine Objectives– At the conclusion of this presentation, participants will be able to … • Summarize the best means for optimizing the transfusion of – and reducing the need to transfuse – surgical patients; • Describe special transfusion considerations for patients in emergent need of blood.

3. Surgical Transfusion Medicine – Outline 1/2 • Preoperative Approaches • Correcting Anemias Prior to Surgery • Preventing Unnecessary and Iatrogenic Blood Loss • Preoperative Autologous Blood Collections • Intraoperative Approaches • Intraoperative Blood Salvage • Acute Normovolemic Dilution • Postoperative Approaches

4. Surgical Transfusion Medicine – Outline 2/2 • Transfusions in Emergency Situations • Introduction • What is Shock (Especially, Hemorrhagic Shock)? And … • … What Are Its Consequences? • The Nuts and Bolts of Emergency Transfusions • Challenges Associated with Massive Transfusions

5. Surgical Transfusion Medicine Preoperative Approaches • Correcting Anemias Prior to Surgery • Preventing Unnecessary and Iatrogenic Blood Loss • Preoperative Autologous Blood Collections

6. Correcting Anemias • The surgeon must decide if the level of anemia and the risk of surgical blood loss from the planned procedure require specific action • Elective surgeries should generally be delayed until treatable preoperative anemias can be corrected • Oral/intravenous iron + erythropoietin (if practicable) may be warranted in some cases • In other cases, different approaches may be required – e.g., to correct a different, underlying cause of anemia

7. Preventing Unnecessary Blood Loss • Restrict diagnostic phlebotomies via the ordering of fewer tests and the practice of lower volume blood draws • Manage anticoagulation carefully, e.g., discontinue or modify the use of anti-clotting agents such as: • Aspirin • Other anti-platelet agents (e.g., clopidogrel) • Anticoagulants (e.g., heparin and warfarin)

8. Preoperative Autologous Collection • “Self-donated” blood • “Target” usually is RBCs • Relaxed donor eligibility criteria • Minimum hematocrit = 33% • No absolute minimum age • No absolute weight limits • Increased donation frequency

9. Preoperative Autologous Blood – Contraindications • Significant cardiac abnormalities (e.g., aortic stenosis, severe coronary artery disease or congestive heart failure) • Very recent myocardial infarct or cerebrovascular accident • Potential bacteremia • Hematocrit < 33% • < 72 hours from time of surgery

10. Preoperative Autologous Blood – Risks • Development of anemia due to donation process (see Kanter et al.) • Small risk of septic & several other transfusion reactions • Remote risk of wrong blood unit being transfused • Blood will not be immediately available in an emergency

11. Preoperative Autologous Blood – Other Issues Preop Auto Blood Donations Before Elective Hyster-ectomy. M.H. Kanter et al. JAMA. 1996; 276: 798-801. • Design: Retrospective; compared 140 elective hyster- ectomy patients who gave auto blood with 123 who didn’t. • Results: 25 of 140 autologous donors were transfused (3 with allogeneic RBCs); 1 of the other 123 was transfused (p < 0.001). • Conclusion: “For hysterectomy patients, donation of autologous blood causes anemia and is associated with a more liberal transfusion policy. Elimination of preoperative autologous donation for these patients should not result in frequent exposure to allogeneic blood”

12. Preoperative Autologous Blood – Other Issues • Venous access • Iron supplementation • Special handling • Fees • Unused autologous units are destroyed

13. Preoperative Autologous Blood – More Issues • Crossover to allogeneic supply – Virtually never done • Transfusion criteria for autologous blood are sometimes debated – Should they be same as, or different from, those for allogeneic blood? • Local hospitals have varying policies regarding the use of confirmed HBV- and HIV-infected units • Cost-effectiveness – In many situations, the use of preoperatively collected autologous blood may never by cost-effective (per traditionally utilized criteria)

14. Autologous Blood Transfusions in Total Joint Replacement Surgery:The Marshall Hospital/BloodSource Experience C. Gresens et al. Transfusion 2002; 42 (Suppl): 18S-19S.

15. Marshall Hospital/BloodSource Total Joint Replacement (TJR) Surgery Blood Use Study • Background • Many orthopedic surgeons advise their total joint replacement surgery patients to consider making preoperative autologous blood donations (PABDs) to reduce the need for perioperative allogeneic transfusions. • We examined the use of blood transfusions by such patients to understand better the impact of PABDs on perioperative transfusion requirements.

16. Marshall Hospital/BloodSource TJR Surgery Blood Use Study Methods: Retrospective review of primary, one-joint TJR surgery patient charts (at Marshall Hospital) and autologous donor charts (at BloodSource). • Blood volume was estimated as: Patient mass (kg) x 0.069 L/kg (male) or 0.065 L/kg (female). • Autologous blood was transfused as pRBCs. • Perioperative blood salvage was not used. • Criteria for transfusion of autologous and allogeneic blood were identical.

17. Marshall Hospital/BloodSource TJR Surgery Blood Use Study Results • Date Range: July 2000-March, 2001 • N = 43 (19 male; 24 female) • Surgical Procedures: Primary, unilateral joint replacement surgeries: • Knee--29 (67%); Hip--14 (33%) • Ages of Patients: Mean = 67.1 (45-86 years)

18. Marshall Hospital/BloodSource TJR Surgery Blood Use Study • Twenty-four patients (57%) made PABDs: • 17 (71%) were knee surgery patients • 7 (29%) were hip surgery patients • PABD Profile • Mean # of PABDs/patient = 1.9 (1-2) units • In total, 45 PABDs were made by these 24 patients.

19. Marshall Hospital/BloodSource TJR Surgery Blood Use Study • Summary of hematocrit data for the “non-autologous donor/patients,” immediately prior to surgery (n = 19) • Average Hematocrit = 42.2% (35.6-to-49.6%)

20. Marshall Hospital/BloodSource TJR Surgery Blood Use Study • Mean Estimated Blood Volumes • Autologous Donor/Patients: 5.8 L • Non-Autologous Donor/Patients: 5.5 L (p > 0.05)

21. Marshall Hospital/BloodSource TJR Surgery Blood Use Study • Nine of the 24 autologous donor/patients (39%) required perioperative autologous RBC transfusions • Mean = 1.9; Median = 2; Range = 1-2 units; • Five (56%) were knee and 4 (44%) were hip; • 17 total auto units transfused. • Only one of the 19 non-autologous donor/patients (5%) required a single allogeneic RBC transfusion (p < 0.05).

22. Marshall Hospital/BloodSource TJR Surgery Blood Use Study Conclusions: • PABDs prior to TJR surgery were associated with: • A moderate reduction in patient hematocrits; • A large increase in perioperative transfusions; • 62% of PABDs not transfused. • PABDs no longer are routinely recommended for primary, one-joint TJR surgery patients at Marshall Hospital.

23. Preoperative Autologous Blood – Other Issues The Cost Effectiveness of Preoperative Autologous Blood Donations. J Etchason, L Petz, et al. NEJM. 1995; 332: 719-724. • Design: Decision-analysis model for cost effectiveness assessment (based upon 1992, UCLA data); looked at total hip replacement, coronary artery bypass grafting, abdominal hysterectomy, & transurethral prostate resection patients. • Results: “The cost-effectiveness values ranged from $235,000 to over $23 million per quality-adjusted year of life saved.” • Conclusion: “The increased protection afforded by donating autologous blood … may not justify the increased cost.”

24. Surgical Transfusion Medicine Intraoperative Approaches Intraoperative Blood Salvage Acute Normovolemic Dilution

25. Intraoperative Blood Salvage • Collection and re-infusion of blood lost during surgery • Alternative to pre-operative autologous blood collection • Can be especially useful for massively bleeding patients • Semi-automated systems are available for this purpose

26. Intraop Blood Salvage – Considerations • Washed vs. unwashed? • Guaranteed blood compatibility • May be acceptable to Jehovah’s Witnesses (particularly if the collection/reinfusion circuit is circular)

27. Intraoperative Blood – Contraindications • Infection/contamination of surgical field • Cancer involving surgical field

28. Perioperative Blood Salvage – Risks • Coagulopathy • Hemolysis • Air embolism (Linden et al.)

29. Perioperative Blood Salvage – Risks Fatal Air Embolism Due to Perioperative Blood Recovery. J.V. Linden et al. Anesth Analg. 1997; 84: 422-426. • Design: Retrospective review of 127,586 periop blood salvage procedures (PBSPs) and 8,955,619 conventional transfusions (CTs); 1990-1995. • Results: 4 fatal air embolism cases occurred in association with PBSPs (1 in 30,000-38,000); none with CTs. • Conclusion: Even when considering all the other risks associated with CTs, the risk for a fatal complication during PBSP is far higher than that for CTs.

30. Acute Normovolemic Hemodilution (ANH) • ANH involves collecting blood from a patient in the OR at the start of surgery, for re-infusion later in the surgery or during the immediate postoperative period. • > 4 units may be removed (with simultaneous 3:1 crystalloid or 1:1 albumin replacement). • In properly selected and monitored patients, a target Hct of 20-25% may be acceptable.

31. Acute Normovolemic Hemodilution – Considerations • Lowers blood viscosity • Reduces RBC loss during surgery • No testing required • Ideal candidate has good preop hematocrit & will lose > 1 L intraoperatively • Exclusion criteria include anemia, renal failure, signifi-cant coronary artery disease, and others

32. Acute Normovolemic Hemodilution – Risks • Critical organ ischemia • Dilutes circulating coagulation factors

33. Surgical Transfusion Medicine Postoperative Approaches

34. Post-operative Blood Salvage • Cardiac & orthopedic surgical patients • Blood collected from drainage devices • Defibrinogenated • Unwashed • Can only be stored for up to 6 hours at room temperature

35. Post-operative Blood Salvage Red Cell Loss Following Orthopedic Surgery: The Case Against Postoperative Blood Salvage. J. Umlas et al. Transfusion. 1994; 34: 402-406. • Design: The volume of salvaged RBCs was measured for the first 6 hours postoperatively & compared to total RBC loss and volume of allogeneic RBCs transfused. • Results: Mean postoperative RBC losses in 31 THR & 20 TKR patients were 55 + 29 and 121 + 50 mL, respectively. • Conclusion: “The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique.”

36. Surgical Transfusion Medicine Transfusions in Emergency Situations Introduction What is Shock (Especially, Hemorrhagic Shock)? And … … What Are Its Consequences? The Nuts and Bolts of Emergency Transfusions Challenges Associated with Massive Transfusions

37. Emergency Transfusions – Introduction • A variety of indications exists for the use of blood transfusions in emergency medicine • This discussion will focus primarily on those transfusion indications pertaining to hemorrhage; however, other reasons for emergency transfusions exist, including all of the ones for which patients generally require transfusions, such as . . .

38. Emergency Transfusions – Introduction … Selected Examples of Non-Hemorrhagic Indications for Emergency Transfusions: • Complications of sickle cell disease or thalassemia; • Worsening chronic anemia or thrombocytopenia in a patient with leukemia, myelodysplasia, etc.; • Severe hemolysis secondary to warm autoimmune hemolytic anemia; • . . .

39. Emergency Transfusions – Introduction • Most trauma patients are treated without transfusions being performed. • A five-year study at Vanderbilt University revealed that only 27% of patients admitted for trauma at their institution required blood (Wudel JH et al: Massive Transfusion: “Outcome in Blunt Trauma Patients.” J Trauma 31: 1, 1991).

40. Emergency Transfusions – Introduction • Another study, looking at 8,000 trauma patients at Cooper Hospital (Camden, NJ), over a similar time period, showed that only 8% needed transfusions(Ross S & Jeter E. In: Clin. Pract. of Transf. Med., 3rd ed. (eds. Petz LD, et al.), 1995.). • Still, a significant minority of trauma patients require transfusions – sometimes MASSIVE TRANSFUSIONS (usually defined as the transfusion of one blood volume of RBCs within 24 hours).

41. Shock • The primary indication for the administration of IV fluids and blood in trauma/emergency surgery patients is hemorrhagic shock. • Definition of shock: Pathophysiologic inadequacies in both: • The delivery of substrate and O2and … • … The removal of metabolic end-products from peripheral tissues.

42. Types of Shock • Hemorrhagic: Caused by severe blood loss; • Metabolic: Associated with profound fluid loss due to injury or illness (e.g., burns or dehydration); • Septic: Caused by the toxins fromsevere (usually bacterial) infections; • Neurogenic: Usually caused by head/spinal injuries; • Psychogenic: Also known as fainting; • Anaphylactic: Due to severe allergic reactions; • Cardiogenic: Caused by damage/injury to heart.

43. Most Common Causes of Hemorrhagic Shock • Penetrating trauma • Blunt trauma • GI bleeding • Ob/Gyn bleeding. Graphics from MDChoice.com

44. High velocity gunshot wound (MDChoice.com) Trauma to legs caused by train (MDChoice.com) Shock – Its Coagulopathic Consequences • Often in shock, a coagulopathy results due to the activation and/or consumption of coagulation factors. • Certain crush injuries (especially cerebral) can lead to DIC (disseminated intravascular coagulation).

45. Shock – Its Coagulopathic Consequences DIC is coagulation activation occurring to an abnormal degree, with so much thrombin generated that it overwhelms the natural thrombin inhibitors. From Merck Manual Online (2003)

46. Shock – Its Coagulopathic Consequences Ultimately, DIC results in: • Activation (and, often, depletion) of other coagulation factors • Fibrinolytic bleeding (the major clinical sign of DIC) and hemolysis (microangiopathic hemolytic anemia) • Thromboses (sometimes more subtle, resulting in CNS deficits, acute renal failure, and/or other organ ischemia)

47. Shock – Its Coagulopathic Consequences Fibrinolysis predisposes the patient to bleeding, both directly (via destruction of fibrin clot) and indirectly (via compromised platelet function). Normal Blood Clot Formation Fibrinolysis naturally allows for the control and remodeling of clots, and normally is a healthy process. When it occurs in concert with DIC, however, it can contribute heavily to bleeding (MDChoice.com).

48. Shock – Some of Its Other Consequences • Acidosis may result from inadequate O2 delivery and waste product removal. • The loss of thermal regulation and a decrease in heat production (which may be worsened both by the environment and the use of cold intravascular fluids) may cause in vivo dysfunction of platelet and clotting factor function. • Prolonged shock ultimately can lead to multisystem organ failure and (eventually) death.

49. Management of Emergency Transfusions Important factors affecting the management of emergency (especially massive) transfusions include: • Experience of trauma care providers; • Availability and quality of ICUs and ORs; • Turnaround time for STAT hematology/coagulation testing; • Reliability (largely related to staffing experience and levels) of transfusion service.

50. Decision to Transfuse Emergently The decision to transfuse (urgently or otherwise) requires a detailed clinical analysis, looking at: • The patient’s clinical condition; • His/her initial hemoglobin level, platelet count, PT (INR), PTT, and fibrinogen level; • His/her response to fluid resuscitation; • Coexisting cardiac, respiratory, and vascular conditions; • Measurements of tissue oxygenation.