Transfusion Reactions: TRALI, TACO, FNHTR, Hemolytic, Allergic

Your Path

  • Transfusion Reactions: TRALI, TACO, FNHTR, Hemolytic, Allergic


  • TRALI (Transfusion Associated Lung Injury): thought to be reaction to antibodies within the plasma component of transfusion, with resultant acute lung injury w/non-hydrostatic pulmonary edema; can occur with infusion of any blood products (e.g. PRBCs, platelets, cryo, FFP)
  • TACO (Transfusion Associated Circulatory Overload): acute sob related to volume and oncotic load (ie hydrostatic pulmonary edema) from PRBCs:
  • Febrile Non-Hemolytic Transfusion Reaction (FNHTR): most common type of transfusion reaction; caused by cytokines in transfused product (platelets or PRBCs) or recipient antibody-donor antigen reactions
  • Allergic: reaction to antigens in transfused product, most commonly associated with platelets
  • Acute hemolytic: response to mismatch of donors to recipient (clerical error or patient misidentification)
  • Other: delayed hemolytic (occurs in those who have had multiple transfusions in past; response to allergens); septic (from bacterial contamination of transfused products)

Risk Factors

  • TACO and TRALI can overlap
  • TACO: hx or risk of diastolic HF, recent infusion of volume (IVF, other blood products) w/positive fluid balance, older age, CKD
  • Acute transfusion reaction: incorrectly labeled blood specimen for typing, wrong product sent to wrong patient, failure to confirm at time of infusion
  • Delayed transfusion reaction: transfusion w/products previously


  • TRALI: w/in 6h (often w/in 1-2h) of receiving blood product; acute sob, can have fever
  • TACO: acute sob, within 6 hours (or less) of receiving PRBCs
  • FNHR: elevated temp; hypertension, chills, rigor
  • Allergic: ranges from mild to anaphylactic reaction; occurs during transfusion or w/in 4h of completion; wheezing; urticaria, erythema and edema most often affecting face, neck, chest; tachycardia and hypotension if severe
  • Acute hemolytic: Fever, chills, hypertension or hypotension, sob, flank pain, reddish urine, bleeding, oliguria; within minutes of starting to hours after transfusion
  • Delayed reaction: Symptoms often vague or inapparent, depending on degree hemolysis; can include fatigue, jaundice; 2 days to 1 month after transfusion; not acutely ill

Physical Exam Findings

  • TACO: SOB, tachycardia, tachypnea, hypertension, hypoxemia, elevated jvp, rales, edema (i.e. signs of volume overload)
  • TRALI: Fever, SOB, tachycardia, tachypnea, hypoxemia, sometimes hypotension, rales, not grossly volume overloaded
  • Allergic: wheezing, urticaria, erythema
  • Acute transfusion reaction: often with acute illness with hypo or hypertension, other
  • Delayed transfusion reaction: jaundice, pallor