Transfusion-related acute lung injury (TRALI) - NYSORA

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Transfusion-related acute lung injury (TRALI)

Learning objectives

  • Describe the risk factors and pathophysiology of TRALI
  • Diagnose and manage TRALI
  • Prevent TRALI


  • Transfusion-related acute lung injury (TRALI) is a transfusion reaction characterized by an acute, noncardiogenic pulmonary edema associated with hypoxia 
  • The leading cause of death from transfusion 
  • Caused by damage to pulmonary vasculature due to the immune response to antibodies or proinflammatory factors from the transfusion product that bind to antigens of the recipient
  • Symptoms include acute dyspnea, fever, hypotension, and tachycardia

Risk factors

  • Mechanical ventilation
  • Sepsis
  • Massive transfusion
  • Coronary artery bypass graft
  • End-stage liver disease
  • Positive fluid balance
  • Critically ill patient
  • Blood products with high plasma contents


  • Two-hit hypothesis:
    • First hit: Priming of neutrophils due to shock, sepsis, organ damage, previous surgery, stress, trauma
    • Second hit: Antibodies or proinflammatory factors in the transfusion product activate neutrophils, resulting in capillary leakage and subsequent pulmonary edema
  • Threshold hypothesis
    • No first hit, a threshold must be overcome to induce TRALI
    • Threshold depends on the susceptibility of the patient and the quantity of antibodies/proinflammatory factors in the transfusion product


  • Diagnostic criteria: 
    • Symptoms develop during or within 6 hours of transfusion without any risk factors for developing acute lung injuries (sepsis from pneumonia, aspiration, shock)
  • Clinical findings:
    • Exudative bilateral infiltrates on chest radiograph
    • No evidence of pulmonary vascular overload
    • Hypoxemia: SpO2 <90% on room air, ratio of partial oxygen pressure to fractional inspired oxygen concentration <300 mmHg
    • Possible TRALI: Other risk factors for acute lung injury
    • Delayed TRALI: 6 – 72 hours after transfusion

Differential diagnosis

  • Septic transfusion reaction: Signs of sepsis
  • Anaphylactic transfusion reaction: Laryngeal and bronchial edema
  • Transfusion-related circulatory overload: Increased pulmonary artery occlusion pressure (>18 mmHg)


  • There is no treatment, management is supportive
  • Stop transfusion
  • Additional oxygen
  • Restrictive tidal volume ventilation
  • Diuretics may be considered


transfusion-related acute lung injury, trali, transfusion, plasma, red blood cells, inflammation, fluid balance, shock, fluid overload, airway pressure, low tidal volume, fresh blood products, washing, report, donor, multiparous, HLA antibody, solgent-detergent plasma

Suggested reading

  • Cho MS, Modi P, Sharma S. Transfusion-related Acute Lung Injury. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from:
  • Vlaar AP, Juffermans NP. Transfusion-related acute lung injury: a clinical review. Lancet. 2013;382(9896):984-994

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