A patient becomes hypotensive and has an oxygen saturation of 88% within 15 minutes of initiating a blood transfusion. What is the most likely diagnosis?

Transfusion-Related Acute Lung Injury (TRALI)

The most likely diagnosis is B. Acute lung injury (TRALI), based on the characteristic presentation of hypotension and severe hypoxemia (SpO2 88%) occurring within 15 minutes of transfusion initiation. 1

Why TRALI is the Correct Diagnosis

• TRALI characteristically presents within 1-2 hours after transfusion with the hallmark triad of hypoxemia, dyspnea, and hypotension—exactly matching this clinical scenario 1, 2

• The presence of hypotension rather than hypertension is the key diagnostic feature that distinguishes TRALI from other transfusion reactions, particularly TACO (transfusion-associated circulatory overload) 1

• The 15-minute timeframe fits perfectly within the typical TRALI onset window, as onset is usually within 4 hours of transfusion and is accompanied by hypotension 2

• TRALI is caused by donor leukocyte antibodies (HLA class I, class II, or granulocyte-specific antibodies) interacting with recipient neutrophils, causing acute respiratory distress and cardiovascular instability 1

Why NOT Acute Hemolytic Transfusion Reaction (Option A)

• Acute hemolytic reactions present with prominent hemolytic signs such as hemoglobinuria, fever, back pain, chest pain, and microvascular bleeding—none of which are mentioned in this case 1

• While hemolytic reactions can cause hypotension, they lack the prominent hypoxemia and respiratory distress that are the defining features of this presentation 1

• The clinical picture here is dominated by respiratory failure (SpO2 88%), not hemolysis 1

Why NOT Allergic Reaction (Option C)

• Allergic reactions typically present with urticaria, pruritus, and bronchospasm, but not with the severe hypotension and profound hypoxemia seen in this case 1

• Simple allergic reactions do not cause SpO2 to drop to 88% within 15 minutes unless progressing to anaphylaxis, which would present with additional features like severe bronchospasm and urticaria 3

• The combination of severe hypoxemia and hypotension points to a more serious pulmonary process than a typical allergic reaction 1

Critical Immediate Management Steps

• Stop the transfusion immediately and maintain IV access with normal saline—this is the single most critical intervention 1, 3

• Administer 100% oxygen to address the severe hypoxemia (SpO2 88%) 1

• Call for help and prepare for potential intubation and mechanical ventilation, as TRALI can progress rapidly 1

• Maintain adequate blood pressure with IV fluid resuscitation using normal saline or lactated Ringer's solution 1

• Do NOT administer diuretics—this is a critical pitfall, as TRALI is non-cardiogenic pulmonary edema and requires supportive care with oxygen therapy, not volume removal 1, 4

Essential Pitfall to Avoid

• The most dangerous error is confusing TRALI with TACO (fluid overload) and administering diuretics 1

• TACO would present with hypertension and cardiovascular changes suggesting fluid overload, not hypotension 1, 5

• Diuretics are ineffective and potentially harmful in TRALI, as hypovolemia should be avoided 1, 4

Post-Stabilization Actions

• Report the reaction to the blood bank immediately to remove the implicated donor from the pool—this is required by the FDA and prevents future cases 1, 3

• Continue observation for at least 24 hours, as TRALI can evolve over the first 6-12 hours post-transfusion 1

• Send post-reaction blood samples for complete blood count, direct antiglobulin test, repeat crossmatch, PT, aPTT, and fibrinogen to exclude hemolytic reaction 1

• Most patients with TRALI recover within 96 hours of symptom onset when managed with immediate supportive care 1