Transfusion Medicine

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Transfusion Medicine

• Cheryl Pollock
• 13 November 03

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Objectives

• An understanding of
• Available blood products
• Appropriate selection of blood products according
  to the clinical setting
• Potential complications of the transfusion

3
Outline

• Blood banking
• Emergency transfusions
• Transfusion reactions and risks
• Component therapy

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Blood Bank Basics

• Type screen
• Blood group (ABO) identification
• Rh typing
• Antibody screening
• Cross-matching

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ABO Identification

• gt400 RBC antigens have been identified
• Major ones are ABO type, and Rh type
• Anti-ABO Abs are IgM that bind complement and
  cause agglutination and destruction of red cells
  gt acute intravascular hemolysis
• Presence of AB antigens are determined by
  testing with anti-A and anti-B Abs

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ABO Compatibility
Phenotype RBC Ag Serum Ab Can receive
A A anti-B A, O
B B anti-A B, O
AB A and B None A, B, O
O None anti-A, anti-B O
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Rh Typing

• Major Rh system Ag is the D Ag
• Rh status determined by testing with anti-D
  antibodies
• Rh-neg females of child-bearing age always get Rh
  neg blood products
• Rh-neg males and elderly females can get Rh-pos
  blood if emergent transfusion required

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Antibody Screening

• To determine presence of
• Complete (agglutinating) antibodies
• Agglutinate RBCs in saline
• Usually IgM
• Responsible for HTR
• Incomplete (non-agglutinating) antibodies
• special techniques to visualize agglutination
• Usually IgG
• Not responsible for HTR

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Antibody Screening

• All antibody screens are negative
• Patient has no unexpected anti-bodies
• Donor blood released after an abbreviated or
  electronic cross-match
• Any antibody screens are positive
• Patient has one/more unexpected antibodies which
  need identification
• Donors must be antigen-negative
• Full cross-match required

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Antibody ScreeningCoombs Test

• Direct Coombs
• To detect Abs or complement on surface Ags of
  RBCs
• Agglutination IgG antibodies in the patients
  serum have bound to recipient RBCs
• Indications
• Hemolytic disease of newborn
• Hemolytic anemia
• Hemolytic transfusion reaction

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Antibody ScreeningCoombs Test

• Indirect Coombs
• Indirect antiglobulin test
• Detect Abs in serum that can recognize Ags on
  RBC.
• i.e. detect Abs capable of hemolysing RBCs
• By mixing serum with donor RBC and then
  anti-antibody Abs RBC agglutination test
• Indications
• Cross-matching -bl gr Abs in pregnant pts
• Atypical bl gr

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Pre-transfusion Testing

• Donor
• ABO and Rh status confirmed
• Recipient
• Abo and Rh determined
• Antibody screening
• For 18 clinically-relevant antigens
• Indirect Coombs
• If positive specific identification, transfusion
  ideally delayed

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Cross-Matching

• Test of donor/recipient RBC compatibility
• Immediate spin cross-match
• Recipient serum donor RBCs, spin tube, read
  immediately
• Detects ABO incompatibility only
• Complete cross-match
• If antibody screen
• Donor units w/out specific Ag are each tested
  with indirect Coombs

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Cross-Matching

• Electronic cross-match
• Donor blood issued based on blood bank info
• Recipients ABO and Rh type has been done twice
  and filed in computer
• No clinically significant antibodies found in
  current or past blood samples
• Contraindications
• Significant antibodies present (current or past)

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Emergency Transfusions

• PRBCs are the only blood product that can be used
  for emergency transfusion
• Plasma products contain too many Abs
• Patient stability and the time available before
  intervention is needed will determine what is
  chosen
• Prior to transfusion, draw blood for typing and
  cross-matching

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Indications for ED Transfusion

• Consider
• Comorbidity -Cardiac status
• Rate of bleeding
• Acute/subacute bleed with impaired oxygen
  delivery to tissues
• Hb lt60-70 g/L
• Symptomatic chronic anemia with Hb lt60-70 g/L
• Pre-op

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Pediatric Pearls

• Hemodynamic parameters can be deceiving
• Normotensive until 30 blood volume lost acutely
• In pediatric trauma, emergency transfusion of gt20
  ml/kg is associated with increased mortality

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Emergency transfusions

• Case 1
• 56 y.o. male, motorcycle vs. car, with open femur
  fracture, unstable pelvis
• HR 130, bp 80/50, intubated at scene for GCS6.
• Blood? How soon?

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Emergency Transfusions

• Universal Donor Group O
• Uncross-matched type O
• Indications
• Massive, uncontrolled hemorrhage from any cause
• e.g. trauma, massive GI bleed, ruptured AAA
• Women of child-bearing age need group O-

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Emergency Transfusions Other Options

• Type-Specific
• 5-10 min
• ABO grouping, Rh typing
• pt can be initially stabilized with crystalloid
• Incomplete cross-match
• 30 min
• ABO group, Rh type, spin cross-match
• Fully cross-match
• 45-60 min
• Reserved for specific patient for 48h

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Administration

• PRBCs
• 1 unit 250ml, Hct 60-70
• 1 unit 10 g/L increase in Hb
• Peds 1ml/kg PRBCs 1 increase in hematocrit
• Bedside check
• Recipient unit i.d., compatibility, expiration
• Large-bore needles to prevent hemolysis
• Blood warmers if massive transfusion
• Blood only mixed with NS no meds in same IV line

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Complications

• Transfusion reaction
• Immediate
• Delayed
• Infectious disease transmission
• Transfusion-associated coagulopathies

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Transfusion Reactions

• Immediate
• Hemolytic
• Intravascular
• Non-hemolytic
• Febrile
• Allergic
• Acute lung injury
• Hypervolemia

• Delayed
• Hemolytic (extravascular)
• Infectious
• Graft v. Host disease
• Electrolyte imbalance

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Transfusion Reactions

• Case 2
• 70 y.o. male transfused for UGI bleed
• Transfusion of first unit PRBCs
• Acutely dyspneic, chest and low back pain, with
  burning at IV site.
• O/E T 39C HR 120 BP 100/60

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Acute Hemolytic Transfusion Reaction
(Intravascular)

• Medical emergency due to ABO incompatibility
  (usually clerical error)
• Incompatible donor cells are destroyed by
  recipient antibodies
• Intravascular cell lysisgt hemoglobinemia and
  hemoglobinuria
• Incidence 1/20 000 transfusions
• Fatal 1/100 000 transfusions

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Acute Hemolytic Transfusion Reaction

• Presentation
• chills, headache, N/V, burning at infusion site,
• Chest tightness, dyspnea, low back pain
• O/E fever, tachycardia, hypotension
• Complications
• Cardiogenic shock, respiratory failure
• ATN
• DIC

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Acute Hemolytic ReactionTreatment Principles

• Prevention
• Slow infusion for 15 min, Q5min VS
• STOP THE TRANSFUSION
• Replace IV tubing
• ABCs
• Hemodynamic stability crystalloid/- pressors
• Adequate renal blood flow
• Low-dose dopamine infusion
• Urine output gt100ml/h (fluid furosemide)

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Acute Hemolytic Reaction

• Evaluation
• Retype and cross-match
• Direct indirect Coombs
• CBC, creatinine, PT/PTT
• Haptoglobin, indirect BR, LDH, plasma free Hb
• Urine for Hb

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Immediate Transfusion Reactions

• Non-hemolytic
• Febrile
• Allergic
• Acute lung injury
• hypervolemia

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Transfusion Reactions

• Case 3
• 58 y.o. female post-elective TAH.
• During transfusion of 1st unit PRBCs, c/o
  malaise, chills, feels warm.
• O/E T 39C HR 90 BP 120/80

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Immediate Transfusion Reactions

• Febrile non-hemolytic
• Impossible to clinically distinguish from acute
  hemolytic reaction
• Caused by Ag-Ab reaction involving
  plasma/components passively transfused
• Usually mild
• Worse if poor CV status, critically ill
• Multi-transfused, multiparous patients

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Febrile Non-hemolytic Reaction

• Presentation
• Fever, chills
• Mgmt
• Stop transfusion
• Initial Rx as per acute hemolytic reaction
• Acetaminophen, meperidine
• Evaluation
• Hemolytic W/U /- infectious W/U

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Allergic Transfusion Reaction

• Anaphylaxis
• Rare (1/20 000 transfusions)
• Suggests IgA deficiency
• Presentation
• Dyspnea, bronchospasm, shock
• Mgmt
• Epi, steroid, anti-histamine, pressors
• Do not restart transfusion
• Hemolytic W/U

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Allergic Transfusion Reaction

• Minor
• Presentation
• Urticaria, pruritis, erythema
• Mgmt
• Stop transfusion
• Anti-histamine
• If symptoms resolve, can restart transfusion
• No further W/U

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Transfusion-Related Acute Lung Injury

• Anti-WBC donor Abs recipient WBC -gt complement
  activation in lung -gt non-cardiogenic pulmonary
  edema
• Clinical diagnosis
• Empiric treatment with steroids and respiratory
  support
• Usually resolves within 48-96h

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Delayed Transfusion Reactions

• Extravascular hemolytic transfusion reaction
• Days to weeks
• Non-ABO Abs bind to RBCs -gt deformation -gt
  splenic sequestration -gt extravascular hemolysis
• Presentation
• Mild reaction
• Fever, jaundice hemoglobinuria rare
• No specific treatment

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Delayed Transfusion Reactions

• All blood tested for
• HIV Ag -HTLV I,II -HBsAg
  -syphilis
• Ab to HIVI, II -HCV -HCAg
• Infectious
• Hep A 1 1 000 000
• Hep B 1 30 000- 1 250 000
• Hep C 1 30 000 1 150 000
• HIV 1 200 000 1 2 000 000
• Data from Goodnough et al. NEJM 340440, 1999

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Delayed Transfusion Reactions

• Case 4
• 44 y.o. male with Non-Hodgkins lymphoma 1/52
  post-chemo
• c/o fatigue, presyncope, SOBOE
• Hb 68
• Risks of transfusion.

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Graft v. Host Disease

• Rarely encountered in ED
• Keep in mind if considering transfusion in anemic
  leukemic/lymphoma pts
• Viable lymphocytes transfused with PRBCs
• Multiplying, histoincompatible lymphocytes attack
  recipient-gtmore BM suppression

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Graft v. Host Disease

• Sx
• Fever, N/V, rash, diarrhea, hepatomegaly
• Increased LFTs, pancytopenia
• No effective treatment
• Fatal
• Prevention
• Gamma irradiation of all cell components,
  rendering donor lymphocytes incapable of
  proliferating

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Delayed Transfusion Reactions

• Electrolyte imbalance
• Hypocalcemia
• Citrate preservative.
• Hyperkalemia
• K leakage across membrane
• Problem in renal failure, neonates

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Dilutional Coagulopathy

• Massive transfusion
• Dilution of platelets coagulation factors
• Check platelets coags after 5-10u PRBC
• Platelet transfusion only if thrombocytopeniamicr
  ovascular bleeding
• FFP only if PT/PTT gt1.5x norm

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Component Therapy

• Platelets
• FFP
• Cryoprecipitate

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Platelet Transfusion

• Indications
• count lt 20 x 109/L lt 50 x 109/L if bleeding or
  planned invasive procedure
• Therapy
• Should be ABO-specific
• Usually 6u at a time increase of 50-60 x109/L
• BUTconsider cause of thrombocytopenia
• DIC, splenomegaly, antibodies may be refractory
  to platelet transfusion

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Fresh Frozen Plasma

• All coagulation factors fibrinogen
• Indications
• Emergent reversal of warfarin therapy
• Correction of coagulation deficiencies
• Therapy
• Must be ABO compatible
• 1u 250ml
• Dose 10-15 ml/kg

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Cryoprecipitate

• Contains
• Factor VIIIC, vonWillebrand Factor, fibrinogen
• Indications
• Bleeding associated with
• Hypo-/dysfibrinogenemia (e.g. DIC)
• vonWillebrands disease if FVIII not available
• Hemophilia A if FVIII not available
• Therapy
• Should be ABO compatible (no cross-match)
• Usual dose 10u

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References

• Marx Rosens Emergency Medicine concepts and
  Clinical Practice, 5th ed.
• Tintinalli. Emergency Medicine A Comprehensive
  Study Guide, 5th ed.
• Ross, AK. Pediatric trauma. Anesthesia
  management. Anesthesiol Clin North Amer. 01 June
  2001 19(2) 309-37

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