Key Concepts
Introduction
TRALI is a non-cardiogenic pulmonary edema occurring within 6 hours of transfusion. Donor antibodies (anti-HLA or anti-HNA) activate recipient neutrophils, which sequester in the pulmonary microvasculature. Activated neutrophils release reactive oxygen species, proteases, and neutrophil extracellular traps (NETs) that damage the alveolar-capillary membrane. This results in increased permeability pulmonary edema with protein-rich fluid flooding the alveoli. A two-hit model suggests that recipient factors (sepsis, surgery, massive transfusion) prime neutrophils, and donor antibodies deliver the second hit. On the exam, writers often pair stable-sounding options with unstable dataโnotice the mismatch before you commit. If the stem names a license or role, reread that line; scope errors are classic trap answers even when the clinical topic is familiar. Run a 60-second scan: breathing work and oxygenation, perfusion and end organs, neuro baseline, likely infection sources, and devices that can fail quietly. When two answers feel partly right, pick the one that reduces imminent harm and matches orders for the role you were given. Train yourself to state the primary risk in one short phrase before you read the options so distractors do...