A 34-year-old man is brought to the hospital by ambulance after being involved in a motor vehicle collision. He was an unrestrained passenger and sustained considerable trauma. On arrival to the emergency department, he is hypotensive and bleeding from several sites. The patient receives an emergency blood transfusion as part of the resuscitation efforts. Abdominal ultrasound reveals splenic laceration and blood in the peritoneal cavity. En route to the operating room, the patient develops difficulty breathing, chills, and pain in the chest and back. Urine drainage from the Foley catheter was initially clear but now appears brown in color. Which of the following is the most likely cause of this patient's new findings?

Question

A 34-year-old man is brought to the hospital by ambulance after being involved in a motor vehicle collision.  He was an unrestrained passenger and sustained considerable trauma.  On arrival to the emergency department, he is hypotensive and bleeding from several sites.  The patient receives an emergency blood transfusion as part of the resuscitation efforts.  Abdominal ultrasound reveals splenic laceration and blood in the peritoneal cavity.  En route to the operating room, the patient develops difficulty breathing, chills, and pain in the chest and back.  Urine drainage from the Foley catheter was initially clear but now appears brown in color.  Which of the following is the most likely cause of this patient's new findings?

Quizplus · Accepted Answer

Eductional Objective: Acute hemolytic transfusion reaction is a antibody-mediated (type II) hypersensitivity reaction caused by pre-existing anti-ABO antibodies that bind antigens on transfused donor erythrocytes.  Subsequent complement activation results in erythrocyte lysis, vasodilation, and symptoms of shock.  Common findings include fever, hypotension, chest and back pain, and hemoglobinuria.

A 34-Year-Old Man Is Brought to the Hospital by Ambulance