TACO & TRALI

Two transfusion complications both cause dyspnea and pulmonary infiltrates — but one is volume overload you can diurese, and the other is immune-mediated lung injury you cannot. Telling them apart changes the intervention completely.

TACO (transfusion-associated circulatory overload) results from too much volume too fast. It presents like classic heart failure: hypertension, elevated JVP, bounding pulse, crackles, and an elevated BNP. Risk factors include elderly patients, those with renal failure or pre-existing heart failure, and rapid infusion rates. Nursing response is to slow or stop the transfusion, position the patient upright, administer diuretics as ordered, and apply supplemental oxygen. TRALI (transfusion-related acute lung injury) is an immune-mediated reaction where donor antibodies activate recipient neutrophils in the pulmonary vasculature, causing noncardiogenic pulmonary edema. It typically strikes within 6 hours of transfusion — most often within 1–2 hours. It presents with acute hypoxemia, bilateral pulmonary infiltrates on chest X-ray, hypotension (not hypertension), and fever. BNP is normal because the heart is not failing. Treatment is supportive: stop the transfusion immediately, provide aggressive respiratory support (often mechanical ventilation), and do not use diuretics — the lungs are leaking from capillary damage, not fluid overload. TRALI is the leading cause of transfusion-related mortality.

Key Distinctions

TACO = hypertension, elevated BNP, responds to diuretics. TRALI = hypotension, normal BNP, diuretics are ineffective or harmful. Students confuse both with hemolytic reactions, but hemolytic reactions feature flank pain, hemoglobinuria, and fever without the primary respiratory picture. The critical differentiator is blood pressure direction: TACO drives it up, TRALI drives it down.

Clinical Pearl

BNP is the tiebreaker: elevated means TACO (fluid overload), normal means TRALI (capillary leak). Think "BNP up = Back off the volume."