Blood Day: The Role of the Anesthesiologist/Perioperative Physician

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Blood Day The Role of the Anesthesiologist/Periop
erative Physician

• Scott Wolfe, MD, FRCPC
• Department of Anesthesia and Perioperative
  Medicine
• University of Manitoba

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Blood Day 2011

• Part 1 Transfusion Considerations
• Complications of transfusion
• Transfusions and outcomes
• When to transfuse (transfusion triggers)

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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

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3rd edition 2011
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• PART 1 Transfusion Considerations
• Provide a framework of concepts which translate
  in the pattern of practice seen in perioperative
  transfusion medicine

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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

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

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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

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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

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

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PART 2

• Case presentation
• Application of perioperative blood conservation
  strategies

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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

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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 mls before trigger
  Hgb of 70
• For Hgb 140 could lose 2400 mls before trigger
  Hbg 70

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Optimizing Preoperative Hbg
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Preoperative anemia

• IV or oral Iron therapy

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I.V. Iron TherapyIndications

• When oral Fe not tolerated
• Urgent pre-op correction of anemia
• Low hgb when transfusion may be imminent

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IV Iron Therapy
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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

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Erythropoietin therapy 2010
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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

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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

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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?

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Mr. X Intraop

• Surgical technique
• ANH
• Cell Salvage
• Antifibrinolytics

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Acute Normovolemic Hemodilution
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ANH for Mr. X

• Starting Hgb 140 g/l
• No ANH if loses 1000ml ? 140 gs of Hb lost
• Undergo ANH to starting hgb of 100
• If loses 1000ml ? 100 gs 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 Jehovahs Witnesses)

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Cell salvage
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Intraoperative cell salvage.
Kuppurao L , Wee M Contin Educ Anaesth Crit Care
Pain 201010104-108
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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

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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
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Case Summary Mr X

• OPTION 2
• BLOOD CONSERVATION
• ?
• Preop hgb 140 with IV Fe
• ?
• Intraop Cellsaver, ANH
• 1.5 l blood loss
• ?
• Postop Hgb 100

• OPTION 1
• Standard
• ?
• Preop Hgb 100
• ?
• Intraop
• 1.5 l blood loss
• ?
• Postop Hgb 70

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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.

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