Cognitive Biases in Early Trauma Transfusions: Lessons From Three Rare Cases of Acute Hemolytic Reaction.

Massive transfusion protocols are essential in trauma resuscitation but may inadvertently increase the risk of acute hemolytic transfusion reactions (AHTRs), which are typically caused by ABO incompatibility. Recognition is difficult because signs of hemolysis can mimic trauma-related hemorrhage or coagulopathy. Cognitive biases in emergency decision-making may further delay diagnosis. Although ABO-incompatible AHTR remains exceptionally rare in trauma, it is easily overlooked in the context of polytrauma. We describe three cases of ABO-incompatible AHTR admitted to a tertiary trauma center. First, a 52-year-old man with multiple injuries received three mis-issued AB+ units instead of group O blood. He developed hemoglobinuria, coagulopathy, and fatal multiorgan failure. The second case involved an 81-year-old man with multiple comorbidities who underwent hip fracture fixation; due to a mislabeled admission sample, he received A+ instead of B+ blood, resulting in persistent anemia, renal failure, and death. The third case was a 30-year-old woman with severe head and thoracic trauma who received incompatible blood under an emergency release protocol. She developed hemolysis, neurologic decline, and sepsis, and ultimately died of multiorgan failure. In all three patients, early post-transfusion anemia and hemodynamic instability were attributed to trauma, delaying recognition of hemolysis. AHTR may therefore be overlooked in trauma settings, where its manifestations overlap with injury-related complications and cognitive biases such as anchoring and premature closure may impair diagnostic reasoning. Strict transfusion safety protocols, heightened vigilance when hemoglobin levels fail to rise, and awareness of cognitive errors may improve early recognition and patient outcomes.