A 24-year-old man is brought to the emergency department via ambulance after sustaining a … — USMLE Step 2 CK

A 24-year-old man is brought to the emergency department via ambulance after sustaining a gunshot wound to his left thigh. On arrival, he is diaphoretic and confused. His temperature is $36.8^\circ\text{C}$ ( $98.2^\circ\text{F}$ ), blood pressure is $82/50\text{ mm Hg}$ , heart rate is $134/\text{min}$ , and respiratory rate is $22/\text{min}$ . Physical examination reveals a single penetrating wound on the anteromedial aspect of the left distal thigh. There is a rapidly expanding, pulsatile hematoma surrounding the wound, and bright red blood is actively spurting from the site. The left foot is pale and cold to the touch. The dorsalis pedis and posterior tibial pulses are not palpable on the left but are $2+$ on the right. Intravenous access is established, and isotonic fluid resuscitation is initiated. Which of the following is the most appropriate next step in management?

A
Computed tomography angiography of the lower extremities
B
Measurement of the ankle-brachial index
Immediate operative explorationAnswer
D
Duplex ultrasonography of the left lower extremity
E
Local wound exploration in the emergency department

Answer

Immediate operative exploration

The correct answer is immediate operative exploration. This patient presents with a penetrating extremity injury and classic 'hard signs' of vascular injury, which include active pulsatile bleeding, an expanding or pulsatile hematoma, absent distal pulses, palpable thrill or audible bruit, and signs of distal ischemia (pallor, paresthesia, paralysis). The presence of any single hard sign—and particularly multiple hard signs combined with hemodynamic instability (hypotension, tachycardia, altered mental status)—mandates emergent surgical intervention in the operating room for hemorrhage control and vascular repair. Any delay to obtain imaging is contraindicated and potentially fatal.

Step-by-Step Solution

Identify the patient's hemodynamic status.

The patient has a blood pressure of

82/50\text{ mm Hg}

and a heart rate of

134/\text{min}

, indicating hemodynamic instability and hemorrhagic shock.

Hemodynamic status dictates whether the patient can safely undergo imaging or requires immediate intervention.

Evaluate the clinical signs associated with the extremity wound.

The patient exhibits active pulsatile bleeding, an expanding hematoma, absent distal pulses, and distal ischemia (cold, pale foot).

These findings are classic 'hard signs' of arterial injury.

Determine the appropriate clinical pathway based on findings.

The presence of hard signs of vascular injury, especially combined with hemorrhagic shock, necessitates emergent transport to the operating room.

Any delay for imaging or bedside procedures in this scenario can lead to exsanguination or irreversible limb ischemia.

Key Concept

Management of penetrating extremity trauma requires immediate operative exploration when hard signs of vascular injury or hemodynamic instability are present.

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