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Difficulty: HardTrauma and Burns

Emergency medical services transport a 39-year-old unrestrained driver to the trauma bay following a high-speed collision with a concrete barrier. Upon arrival, he is unresponsive and is immediately intubated for airway protection. His heart rate is 142/min and blood pressure is 74/40 mm Hg. Physical examination shows extensive bruising across the sternum. Breath sounds are diminished on the left side. A left-sided chest tube is inserted, yielding 250 mL of gross blood. Bedside ultrasonography (FAST) demonstrates normal cardiac motion without pericardial effusion and no free fluid in the peritoneal cavity. Anteroposterior radiographs of the chest and pelvis are obtained. The pelvic film is unremarkable. The chest radiograph demonstrates a widened mediastinum, obscured aortic contour, and a left apical pleural cap. The patient's hemodynamics do not improve despite the initiation of a massive transfusion protocol. Which of the following is the most appropriate next step in the evaluation of this patient?

  1. A
    Computed tomography angiography of the chest
  2. B
    Diagnostic peritoneal aspiration
  3. C
    Emergency department resuscitative thoracotomy
  4. D
    Exploratory laparotomy
  5. Transesophageal echocardiographyAnswer

Answer

Transesophageal echocardiography
The patient's clinical presentation (high-speed deceleration injury, profound hypotension) and radiographic findings (widened mediastinum, left apical cap, obscured aortic knob) are highly suspicious for a blunt aortic injury (BAI). The management of suspected BAI depends entirely on the patient's hemodynamic status. For hemodynamically stable patients, computed tomography angiography (CTA) of the chest is the gold standard diagnostic test. However, this patient is hemodynamically unstable and unresponsive to massive transfusion. Transporting an unstable trauma patient to the CT scanner is strictly contraindicated due to the high risk of fatal decompensation away from the resuscitation bay. Therefore, transesophageal echocardiography (TEE) is the most appropriate next step, as it can be performed rapidly at the bedside in the emergency department or intraoperatively to confirm the diagnosis prior to definitive surgical or endovascular repair.

Step-by-Step Solution

1
Identify the primary life-threatening condition.
The patient is in profound hemorrhagic shock (HR 142/min, BP 74/40 mm Hg) that is unresponsive to initial massive transfusion.
Recognizing instability dictates the diagnostic algorithm, precluding any imaging that requires transporting the patient away from the resuscitation area.
2
Localize the source of hemorrhage based on initial primary survey adjuncts.
FAST is negative and pelvic X-ray is normal, effectively ruling out the abdomen and pelvis. The chest radiograph shows a widened mediastinum and obscured aortic contour.
These classic radiographic findings, combined with a high-energy deceleration mechanism, make blunt aortic injury the most likely diagnosis.
3
Determine the appropriate diagnostic or therapeutic next step for blunt aortic injury based on hemodynamic status.
Because the patient is unstable, computed tomography angiography (CTA) is contraindicated. The next step is transesophageal echocardiography (TEE) at the bedside or in the operating room.
TEE provides rapid visualization of the thoracic aorta to confirm the injury without risking fatal decompensation in the radiology suite.

Key Concept

In hemodynamically unstable patients with suspected blunt aortic injury, transesophageal echocardiography (TEE) is the diagnostic test of choice because it avoids transporting a critically ill patient to the CT scanner.
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Topics

Trauma and Burns

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