Transfusion-Related Acute Lung Injury (TRALI)
The diagnosis is B. Acute lung injury (TRALI), characterized by the hallmark triad of hypoxemia (SpO2 88%), hypotension, and dyspnea occurring within 1-2 hours (15 minutes in this case) after transfusion. 1, 2, 3
Why TRALI is the Correct Diagnosis
The presence of hypotension rather than hypertension is the key diagnostic feature that distinguishes TRALI from TACO (circulatory overload). 2, 3 This patient presents with:
- Acute hypotension (not hypertension) 2, 3
- Severe hypoxemia (SpO2 88%) 1, 2
- Timing within 1-2 hours of transfusion (15 minutes is well within this window) 1, 2, 3
The mechanism involves donor leukocyte antibodies (HLA class I, class II, or granulocyte-specific antibodies) interacting with recipient neutrophils, causing non-cardiogenic pulmonary edema and acute respiratory distress with cardiovascular instability. 2, 3
Why NOT the Other Options
Option A: Acute Hemolytic Transfusion Reaction
- While acute hemolytic reactions can cause hypotension, they typically present with additional features such as fever, back pain, chest tightness, dark/soy sauce-colored urine (hemoglobinuria), and signs of hemolysis. 4, 5, 6
- The primary presenting feature is hypoxemia (SpO2 88%), which is the dominant clinical finding in TRALI, not hemolytic reactions. 1, 2
- Hemolytic reactions would require laboratory confirmation with direct antiglobulin test, serum hemolysis testing, and evidence of blood group incompatibility. 4
Option C: Allergic Reaction
- Allergic transfusion reactions typically present with urticaria, rash, pruritus, and possibly bronchospasm. 1
- Severe hypotension with profound hypoxemia is not characteristic of simple allergic reactions unless progressing to anaphylaxis, which would present with additional features like angioedema, wheezing, and stridor. 1
- The timing and combination of hypotension with severe hypoxemia points more specifically to TRALI. 2, 3
Critical Immediate Management
Stop the transfusion immediately and maintain IV access with normal saline. 2, 3 This is the single most critical intervention that can prevent progression to severe morbidity or mortality. 1
Administer 100% oxygen (high FiO2) to address the severe hypoxemia. 2, 3 Call for help and prepare for potential intubation and mechanical ventilation. 2, 3
Maintain adequate blood pressure with IV fluid resuscitation using normal saline or lactated Ringer's solution. 2, 3
Critical Pitfall to Avoid
Do NOT administer diuretics. 2, 3 This is the most dangerous error in TRALI management. TRALI is non-cardiogenic pulmonary edema requiring supportive care with oxygen therapy and critical care measures, not volume removal. 3 Diuretics are ineffective and potentially harmful in TRALI. 2, 3
TACO (which would require diuretics) presents with hypertension and cardiovascular changes suggesting fluid overload, not hypotension. 2, 3
Post-Stabilization Actions
- Send baseline labs immediately: CBC, PT, aPTT, fibrinogen, direct antiglobulin test (DAT), repeat cross-match, and visual inspection of plasma for hemolysis to exclude hemolytic reaction. 2, 3
- Report the reaction to the blood bank immediately to remove the implicated donor from the pool. 2, 3 TRALI is underdiagnosed and underreported despite being a leading cause of transfusion-related mortality. 1, 3
- Continue observation for at least 24 hours, as TRALI can evolve over the first 6-12 hours post-transfusion. 2, 3
- Monitor vital signs every 5-15 minutes until stable. 1, 2