How should I manage an acute transfusion reaction?

Management of Acute Blood Transfusion Reactions

Stop the transfusion immediately when any signs of a reaction occur (tachycardia, rash, breathlessness, hypotension, or fever), maintain IV access with normal saline, and assess for anaphylaxis to determine whether epinephrine is needed. 1

Immediate Actions (First 60 Seconds)

• Stop the blood transfusion immediately but keep the IV line open with normal saline for medication administration and fluid resuscitation 1
• Assess ABCs (Airway, Breathing, Circulation) and the patient's level of consciousness 1
• Call for medical assistance as soon as possible 1
• Position the patient appropriately: Trendelenburg position for hypotension, sitting upright for respiratory distress, or recovery position if unconscious 2, 1
• Administer supplemental oxygen if needed 2, 1
• Monitor vital signs including heart rate, blood pressure, temperature, and respiratory rate 1
• Contact the transfusion laboratory immediately and send the blood unit with administration set for investigation 1

Critical Early Warning Signs

Take seriously any patient who feels "odd" or uncomfortable, or expresses a need to urinate or defecate—these are early warning signs requiring immediate blood pressure and pulse rate measurement 2

Determine Reaction Type and Severity

ANAPHYLAXIS (Life-Threatening)

Criteria: Hypotension, respiratory distress, angioedema, or severe bronchospasm occurring within minutes of transfusion

Management:

• Epinephrine 0.2-0.5 mg (1 mg/mL) IM into the lateral thigh muscle—repeat every 5-15 minutes as needed 2, 1
• Aggressive fluid resuscitation: Normal saline 1-2 L IV at 5-10 mL/kg in the first 5 minutes, then crystalloids or colloids in 20 mL/kg boluses 2, 1
• H1/H2 antagonists: Diphenhydramine 50 mg IV plus ranitidine 50 mg IV 2, 1
• Corticosteroids: Methylprednisolone 1-2 mg/kg IV every 6 hours 2, 1
• If bradycardia develops: Atropine 600 μg IV 2
• If hypotension persists despite epinephrine and fluids: Dopamine 400 mg in 500 mL at 2-20 μg/kg/min, or vasopressin 25 U in 250 mL (0.1 U/mL) at 0.01-0.04 U/min 2
• If patient is on beta-blockers: Glucagon 1-5 mg IV infusion over 5 minutes 2

MILD TO MODERATE REACTIONS (Grade 1-2)

Criteria: Urticaria, pruritus, mild fever (<1°C increase), or mild flushing without hypotension

Management:

• Slow the infusion rate to 50% of original rate 2, 1
• H1/H2 antagonists: Diphenhydramine 50 mg IV plus ranitidine 50 mg IV 2, 1
• Corticosteroids: Methylprednisolone 1-2 mg/kg IV every 6 hours 2, 1
• Restart infusion at 50% rate and titrate to tolerance if symptoms resolve 2

SEVERE NON-ANAPHYLACTIC REACTIONS (Grade 3-4)

Criteria: Severe fever (>1°C increase), rigors, severe urticaria, or respiratory symptoms without anaphylaxis

Management:

• Stop the infusion permanently 2, 1
• H1/H2 antagonists: Diphenhydramine 50 mg IV plus ranitidine 50 mg IV 2, 1
• Corticosteroids: Methylprednisolone 1-2 mg/kg IV every 6 hours 2, 1
• Do not rechallenge with the same blood product 2

FEBRILE NON-HEMOLYTIC REACTION

Criteria: Temperature increase >1°C during transfusion without other symptoms 1

Management:

• Administer IV paracetamol only—avoid routine steroids or antihistamines 1
• Monitor closely for progression to more severe reaction 1

Post-Reaction Monitoring

• Monitor vital signs continuously until complete resolution of symptoms 2, 1
• 24-hour observation is mandatory for severe reactions to detect biphasic reactions 2, 1
• Assess urine output and color to monitor for hemolytic reactions 1
• Monitor peak airway pressure to detect transfusion-related acute lung injury (TRALI) 1
• Measure brain natriuretic peptide (BNP) if transfusion-associated circulatory overload (TACO) is suspected 1

Special Considerations

Patients on ACE Inhibitors

Patients taking angiotensin-converting enzyme (ACE) inhibitors are at increased risk for acute hypotensive transfusion reactions (AHTR), characterized by isolated profound hypotension without other symptoms 3, 4. If AHTR occurs, switch to another class of antihypertensive medication while the patient requires transfusions 3.

Anesthetized Patients

General anesthesia masks symptoms of both hemolytic and non-hemolytic transfusion reactions 1. In anesthetized patients, unexplained hypotension, bleeding diathesis, or hemoglobinuria should prompt immediate investigation for transfusion reaction 5.

Patients Requiring Vasopressors

For patients requiring both blood transfusion and vasopressors, ensure vital signs are checked at least every 15 minutes and consider separate IV access sites 1. Avoid rapid transfusion due to increased TACO risk 1.

Critical Pitfalls to Avoid

• Never delay epinephrine if anaphylaxis is suspected—it is the only life-saving medication in anaphylaxis 2, 1
• Do not use corticosteroids alone without antihistamines in acute reactions—corticosteroids provide no acute benefit and only prevent biphasic reactions 2
• Do not restart transfusion at full rate after a reaction—always restart at 50% rate if restarting is appropriate 2
• Do not discharge patients prematurely after severe reactions, especially those with airway involvement or requiring multiple interventions 1
• Do not omit centrifugation and inspection after 37°C incubation in compatibility testing—this can miss clinically significant antibodies 6
• Do not transfuse rapidly in elderly patients (>70 years), those with cardiac failure, renal insufficiency, low body weight, or low serum albumin 1

Prevention for Future Transfusions

• Consider washed blood products for patients with prior allergic reactions 1
• Use slower transfusion rates if TACO occurred previously 1
• Implement prophylactic diuretic therapy for high-risk patients (elderly, cardiac failure, renal insufficiency) 1
• Transfuse RBC units one at a time with interval reassessment in non-bleeding patients 1
• Ensure positive patient identification using at least four core identifiers before transfusion 1
• Visually inspect blood components for leakage, discoloration, or clots before administration 1

Documentation Requirements

• Document the reaction grade, specific symptoms, timing of onset, and all treatments administered 1
• Maintain traceability records for 30 years as a statutory requirement 1
• Report to the hospital transfusion committee for audit and protocol refinement 1