Transfusion-Related Acute Lung Injury (TRALI) is an adverse reaction most often associated with the transfusion of plasma. TRALI is the onset of acute lung injury with hypoxemia (PaO2/FiO2 ≤300 mm Hg or SpO2 <90% on room air) within 6 hours of transfusion in a patient with no previous risk of lung injury. Symptoms include shortness of breath, severe hypoxia, fever, chills, hypotension, and radiographic evidence of new-onset bilateral pulmonary edema, usually presenting within 2–6 hours after transfusion.
Symptoms of TRALI are similar to other adverse reactions to plasma transfusion, such as TACO and allergic reactions (which will be discussed later in the course); thus, the differential diagnosis may be difficult. Mild cases of TRALI may be challenging to recognize, and therefore, the incidence of TRALI may be under-reported. TRALI symptoms often subside within 24–48 hours. The mortality rate associated with TRALI is approximately 5–10% of cases. TRALI was considered the most common cause of transfusion-associated mortality in the US until 2016 when TACO superseded it.
