Transfusion Reaction
Definition | Aetiology | Pathophysiology | Risk Factors | Signs and Symptoms | Investigations | Management
Definition
Transfusion reaction refers to any adverse event occurring during or after a blood transfusion, which can range from mild allergic reactions to life-threatening haemolysis or anaphylaxis.
Aetiology
- Haemolytic transfusion reaction (HTR): due to ABO incompatibility or other red cell antigen mismatches.
- Febrile non-haemolytic reaction (FNHTR): caused by recipient immune response to donor white blood cells or cytokines.
- Allergic reaction: response to donor plasma proteins.
- Anaphylaxis: severe allergic reaction in IgA-deficient individuals receiving plasma containing IgA.
- Transfusion-related acute lung injury (TRALI): immune-mediated lung injury due to donor antibodies.
- Iron overload: from multiple transfusions, particularly in chronic transfusion-dependent patients.
Pathophysiology
- Haemolytic reactions: recipient antibodies attack transfused red cells, leading to haemolysis and organ damage.
- Febrile reactions: cytokine release from white blood cells in stored blood causes fever.
- Allergic reactions: immune system recognises donor plasma proteins as foreign.
- TRALI: neutrophil activation in pulmonary vasculature leads to increased permeability and pulmonary oedema.
Risk Factors
- Previous transfusion or pregnancy (alloantibody formation).
- Multiple transfusions (iron overload, alloimmunisation).
- IgA deficiency (increased risk of anaphylaxis).
- Underlying lung disease (higher risk of TRALI).
Signs and Symptoms
- Haemolytic reaction: fever, chills, hypotension, haemoglobinuria.
- Febrile reaction: fever, rigors, headache.
- Allergic reaction: urticaria, itching, flushing.
- Anaphylaxis: hypotension, bronchospasm, stridor.
- TRALI: acute dyspnoea, hypoxia, pulmonary oedema.
Investigations
- Full blood count (FBC): assess for haemolysis.
- Direct antiglobulin test (DAT): identifies immune-mediated haemolysis.
- Renal function tests: assess for haemoglobinuria-related kidney damage.
- Chest X-ray: if TRALI suspected.
Management
1. Immediate Management:
- Stop transfusion immediately.
- Maintain IV access with normal saline.
- Monitor vital signs and provide supportive care.
2. Specific Management:
- Haemolytic reaction: aggressive IV fluid resuscitation, transfusion of compatible blood if required.
- Febrile reaction: antipyretics (paracetamol), consider leukocyte-depleted blood for future transfusions.
- Allergic reaction: antihistamines, corticosteroids for severe cases.
- Anaphylaxis: IM adrenaline, IV fluids, airway support.
- TRALI: oxygen therapy, ventilatory support if required.
3. Referral:
- Haematology: for investigation of haemolytic reactions or recurrent transfusion reactions.
- Intensive care: if severe TRALI or anaphylaxis occurs.