Transfusion

  • Universal donor: O(-)
  • Universal recipient: AB
  • Rh+/- refers to D antigen specifically
    • Rh(-) people exposed to Rh(+) blood (e.g. transfusion, pregnancy) will form anti-D alloantibody → hemolytic reaction to further Rh+ blood

Type and screen

  • Type = determine recipient ABO and Rh phenotype
  • Screen = screen recipient serum for alloantibodies that may react with donor RBCs
    • If positive, then antibody panel to see if clinically significant
    • If negative, then OK?
  • Cross = Indirect Coomb's with donor RBCs + recipient serum
    • If recipient serum contains antibodies against donor RBC antigens, antibodies will bind RBCs
    • Addition of anti-human IgG will agglutinate antibodies + RBCs = positive Indirect Coombs (= not a good match)
  • Type + Screen - perform on admission if patient has potential need for blood (surgery, severe anemia, high bleeding risk)
    • Takes about 45 minutes, lasts up to 72 hrs
  • Type + Cross should only be ordered if patient needs/likely will need transfusion (active bleeding, trauma, pre-op for major surgery)
    • Blood is taken off the shelf/held for the patient (for ? hrs?), but can be returned if not used

Blood products

  Volume/unit Time to transfuse Expected response Contains
pRBC 300 mL 1 U/4 hrs Hgb by 1, Hct by 3

RBCs, *leukocytes, plasma
Platelet
(apheresis derived)		 300 mL wide open? 30,000 after 1 hr (agenerally returns to baseline by 72 hrs)  
FFP (fresh frozen plasma) 250 mL 1 U/1-2 hrs bTypically need ~ 3-5 U All coagulation factors, proteins found in blood
dPCC (prothrombin complex concentrate) minimal     Factors II, VII, IX, X
Cryo 10-15 mL     Factors VIII, XIII, cfibrinogen, fibronectin, vWF

pRBCs

  • Types of pRBCs
    • *Leukoreduced (which most blood is) - WBCs can cause HLA alloimmunization, fever (e.g. febrile non-hemolytic transfusion reaction)
    • Irradiated - use to avoid graft-versus-host disease; BMT patients; hematologic malignancies
    • Washed - removes residual plasma proteins; use if hx severe allergic reaction to transfusion
    • CMV negative - use in low birth weight infants; transplant patients

Transfusion guidelines

Group Transfusion goals
Symptomatic anemia (chest pain, orthostasis, tachycardia unresponsive to fluids)  Transfuse!
Stable hospitalized/ICU patients > 7 g/dL
Hospitalized with pre-existing heart disease > 7-8 g/dL
Acute coronary syndrome (ACS) 8-10 g/dL?
Active GIB (hemodynamically stable) > 7 g/dL
Cardiac or ortho surgery 8 g/dL

Platelets

  • Main transfusion indications - active bleeding in thrombocytopenic patient
  • aRefractoriness to platelet transfusion - fever, sepsis (cytokine-mediated destruction), active bleeding, splenomegaly, alloimmunization, ABO mismatch, hematpoietic cell transplantation, DIC
    • Transfuse immediately prior to procedure; get repeat CBC after transfusion complete
Situation Transfusion threshold
Active bleeding < 50,000
Prevent spontaneous bleeding < 10,000
Neurosurgery, ocular surgery > 100,000
Most major surgery > 50,000 
Endoscopic procedures > 50,000 (therapeutic)
> 20,000 (diagnostic) 
Central line placement > 20,000 
Lumbar puncture > 50,000
> 20,000 if hematologic malignancy
Epidural > 80,000
Bone marrow biopsy > 20,000

FFP

  • Indications: correct bleeding caused by factor deficiency
    • Warfarin overdose/reversal (if bleeding/needs surgery)
    • Vit K deficiency, liver failure
    • Dilutional coagulopathy after massive transfusion
  • Do not use for minimally elevated INR ≤ 1.6 - INR of FFP can be as high as 1.3
  • When able, use specific coag factor concentrates (e.g. hemophilia, factor VII deficiency)
  • Stored frozen - must wait to thaw before administering
  • bFFP dosing
    • Hemostasis requires coag factors to be at 25-30% of normal level, and plasma volume = 40 ml/kg
    • So a typical adult requires 40 ml/kg x 70 kg x 25% = 700 cc of FFP = 3 U FFP
    • dPCC (e.g. Kcentra) is much more concentrated (reconstituted powder) to deliver less volume (and more quickly, don't need to thaw), but $$$$ - $5000 for vial of PCC vs. $100 for 1 U FFP
      • Dosing for warfarin reversal - 25-50 U/kg

Cryoprecipitate

  • Indications: need fibrinogen - DIC, von Willebrand disease
  • 10 bags cryo contains 2g fibrinogen, will raise fibrinogen by ~70 mg/mL
  • Give cryo if fibrinogen < 100; FFP OK if fibrinogen > 100

Transfusion reactions

  • General approach to fever during transfusion
    • Temp < 1C above baseline, asx - probably OK to continue transfusion (normal rxn)
    • Temp > 1C above baseline, asx - discard blood, continue to monitor
    • Temp > 1C above baseline + symptoms - work up for transfusion reaction; +/- blood cx
Reaction/pathophys Symptoms/time frame Management

Volume-related

TRALI (transfusion related acute lung injury)

  • Can occur with all blood products
  • Rare (1:12,000) but leading cause of transfusion-related mortality in US (mortality 5-8%)
  • ? pathogenesis - donor Abs activate recipient PMNs? clot in pulmonary capillaries?

< 6 hrs

Dyspnea, hypoxemia, pulmonary infiltrates (like ARDS on CXR) - non-cardiogenic pulmonary edema

Fever, tachycardic/tachypnic, hypotension
  • Supportive - may require mechanical ventilation
  • Trial diuretics
  • Alert blood bank

TACO (transfusion related circulatory overload)

  • Risk factors - small/elderly, poor cardiac function
  • Prevent with slow transfusion (1 U pRBC/4 hrs); limit to 2 U/day; lasix in between transfusions

< 6 hrs

Dyspnea, hypoxemia, orthopnea, hypertension
  • Diuretics, O2
  • BiPAP if needed

Metabolic/hematologic

Imbalances seen with massive transfusion

  • ↓ Ca (citrate preservative in blood products chelates Ca)
  • ↑ K, ↑ coags (PT/PTT), ↓ platelets, hypothermia
  • Monitor ionized Ca; K; acid base balance
  • Use blood warmer if transfusing > 3 U
  • Monitor coags/platelets - if PT/PTT > 1.5x normal, transfuse 2 U FFP. If platelets < 50,000, transfuse 1 U platelets

Immunologic/allergic

Febrile nonhemolytic reaction (FNHTR) (most common)

  • Cytokine mediated
  • Use leukoreduced blood to reduce risk

1-6 hrs of RBCs or plts

f/c, ± mild dyspnea
  • Stop transfusion
  • Antipyretics
  • Benign - no sequelae (but take seriously and r/o hemolytic rxn)

Acute hemolytic reaction (AHTR)

  • ABO mismatch (clerical error) with destruction of donor RBCs by preformed recipient antibodies
  • Emergency!!!

within minutes/hours

f/c, flank pain, red/brown urine (hemoglobinuria), hypotension, DIC
  • Stop transfusion but keep IV in
  • ABC's
  • Send blood bag/IV tubing to lab for testing - alert blood bank
  • Begin NS 100-200 ml/hr through same IV (no LR as Ca can clot remaining blood in IV) - flush IV and maintain BP; UOP > 100 ml/hr
  • Draw blood from other arm for direct Coombs, plasma free Hgb (> 5), repeat T&C; urine sample for hemoglobin testing
  • Monitor Cr, coags, fibrinogen, platelets, K

Bacterial infection

  • Higher risk with platelets (kept at room temperature); most commonly GNRs (E. coli)

30 min after tranfusion completed

fevers, rigors, tachy, ↑/↓BP
  • May look like AHTR - follow same steps
  • BCx; empiric abx if high suspicion
  • Send bag to micro lab for gram stain, culture

Delayed hemolytic reaction

  • Recipient antibody response to donor RBC minor antigen previously encountered with transfusion/pregnancy - mild hemolysis
  • Ab titers often undetectable pre-transfusion → elevate after transfusion/exposure

2-10 days post transfusion

↓ Hgb, low fever, mild ↑ indirect bili
  • No tx required unless rapid hemolysis
  • New direct Coombs/Ab screening; educate patient to prevent future antigen exposure

Anaphylactic reaction

  • Emergency!!!
  • Most commonly - IgA deficient patients with anti-IgA

seconds to minutes after initiation

Hypotension, angioedema, respiratory distress 
  • Stop transfusion immediately, treat like anaphylaxis
  • Maintain airway/oxygen
  • IM epi 0.3 ml of 1:1000; methylprednisolone 125 mg IV, ranitidine 50 mg IV, benadryl 50 mg IV
  • IVF for hypotension

Urticarial (allergic) reaction

  • Allergenic substances in donor plasma react with recipient IgE → histamine release
 Urticaria/hives
  • Pause transfusion, give benadryl 25-50 mg
  • If sx resolve, resume transfusion
  • Caution for sx of anaphylaxis

 

Risks of transfusion

Adverse event Risk (per U pRBC)
Febrile reaction 1:60
TACO 1:100
Allergic reaction 1:250
TRALI 1:12,000 
HCV infxn 1:1,150,000 
HBV infxn 1:1,500,000 
HIV infxn 1:1,500,000 
Fatal hemolysis 1:2,000,000 
author: admin | last edited: Jan. 21, 2019, 10:38 p.m. | pk: 110