Transfusion-Related Acute Lung Injury

Abstract

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality among critically ill patients. In the absence of biomarkers, the diagnosis is based on clinical parameters. TRALI is defined as onset of acute lung injury (PaO₂/FiO₂ <300, bilateral infiltrates on the chest X-ray) occurring within 6 h of any blood transfusion. Furthermore, hydrostatic pulmonary edema should be ruled out. The incidence of TRALI is high among critically ill patients, which may be due to a “two-hit” pathogenesis of TRALI. The “first hit” is the underlying condition of the patient resulting in priming of the pulmonary neutrophils. The “second hit” is the transfusion of a blood product resulting in activation of the neutrophils and onset of pulmonary edema. Patients with sepsis, hematologic malignancy, cardiac surgery, mechanical ventilation, and massive transfusion are particularly at risk for the onset of TRALI. The mortality of TRALI is up to 50 % in the critically ill patient population. Currently, no specific therapy exists for this life-threatening syndrome. Focus is on prevention and supportive care. Prevention can be achieved by adapting a restrictive and patient-customized transfusion policy, balancing the benefits and risks of transfusion prior to administering a blood product. Supportive care consists out of mechanical ventilation using low tidal ventilation and adapting a restrictive fluid policy.