1. Prepared by Nicolas A. Giraldo-Castillo
Reviewed by Lorraine N. Blagg, MA, MLS(ASCP)CMSBB

An older adult was admitted to the hospital with altered mental status, decrease in renal function, thrombocytopenia, and COVID-19 infection. They received an apheresis platelet to treat their thrombocytopenia (platelet count of 6 K/cu mm). Approximately four hours after the transfusion, the patient developed shortness of breath, tachypnea, hypertension, decreased SpO2 (down to 82%), and asymmetric lower extremity edema. The patient was eventually intubated and a chest X-ray was consistent with interstitial and alveolar edema, and mild left ventricular dysfunction. A transfusion reaction evaluation was initiated with the clerical check being correct and the gram stain and cultures were negative.

Which is the most likely cause of this patient's acute respiratory distress?