What is the diagnosis for a patient who develops hypotension and decreased oxygen saturation (SpO2) of 88% within 15 minutes after a blood transfusion?

Diagnosis: Transfusion-Related Acute Lung Injury (TRALI)

The patient presenting with hypotension and SpO2 of 88% within 15 minutes of blood transfusion most likely has Transfusion-Related Acute Lung Injury (TRALI), making option B the correct diagnosis. 1, 2

Clinical Reasoning

Why TRALI is the Most Likely Diagnosis

TRALI characteristically presents with non-cardiogenic pulmonary edema within 1-2 hours after transfusion, with the hallmark triad of hypoxemia, dyspnea, and hypotension. 1 The timing (15 minutes post-transfusion) and combination of severe hypoxemia (SpO2 88%) with hypotension are pathognomonic for TRALI. 2

• The mechanism involves donor leukocyte antibodies (HLA class I, class II, or granulocyte-specific antibodies) interacting with recipient neutrophils, causing acute respiratory distress and cardiovascular instability. 1
• TRALI is a leading cause of transfusion-related mortality despite being underdiagnosed and underreported. 1
• The presence of hypotension rather than hypertension is a key diagnostic feature that distinguishes TRALI from other transfusion reactions. 2

Why NOT Acute Hemolytic Transfusion Reaction (Option A)

Acute hemolytic transfusion reactions typically present with fever, hemoglobinuria, jaundice, and pain—not primarily with severe hypoxemia and respiratory distress. 3, 4

• While acute hemolytic reactions can cause hypotension through complement activation and cytokine release, the dominant clinical feature is intravascular hemolysis with hemoglobinuria, not profound hypoxemia (SpO2 88%). 3
• The subjective responses include pain, restlessness, nausea, skin flushing, and dyspnea, but severe hypoxemia is not the primary presenting feature. 4
• Acute hemolytic reactions occur in approximately 1:70,000 units transfused and are usually caused by ABO incompatibility. 3

Why NOT Simple Allergic Reaction (Option C)

Allergic transfusion reactions present with urticaria, pruritus, and rash—not with severe hypoxemia and hypotension unless progressing to anaphylaxis. 5

• Simple allergic reactions are managed with antihistamines or steroids and do not typically cause profound hypoxemia (SpO2 88%). 6
• Anaphylaxis would require additional features such as bronchospasm, angioedema, or urticaria, which are not mentioned in this case. 5
• The combination of isolated hypotension and severe hypoxemia without mention of cutaneous findings makes allergic reaction less likely. 5

Immediate Management Algorithm

Stop the transfusion immediately and maintain IV access with normal saline—this is the single most critical intervention. 1, 5

1. Administer 100% oxygen to address the severe hypoxemia. 1
2. Call for help and prepare for potential intubation and mechanical ventilation. 1
3. Maintain adequate blood pressure with IV fluid resuscitation using normal saline or lactated Ringer's solution. 1
4. Avoid diuretics—they are ineffective and potentially harmful in TRALI, as this is non-cardiogenic pulmonary edema. 1, 2

Critical Pitfalls to Avoid

Do not administer diuretics thinking this is fluid overload (TACO)—TRALI requires supportive care with oxygen therapy and critical care measures, not volume removal. 1

• TACO would present with hypertension and cardiovascular changes suggesting fluid overload, not hypotension. 5, 2
• The timing (15 minutes) and hypotension strongly favor TRALI over TACO. 2
• Transfer to intensive care for continued monitoring and mechanical ventilation if needed. 1

Post-Stabilization Actions

Report the reaction to the blood bank immediately to remove the implicated donor from the pool. 1, 5

• 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. 5