Soft signs present or asymptomatic: Ankle-Brachial Index (ABI) or Arterial Pressure Index (API) for upper extremity.
Key Imaging: Plain radiography (X-ray) of the extremity to assess for concurrent fractures, retained projectiles/foreign bodies, or subfascial air.
Confirmatory/Gold Standard: CT Angiography (CTA).
Indicated if ABI/API < 0.9, abnormal distal pulses, or soft signs present.
Duplex US is an alternative if CTA is unavailable or contraindicated.
Differential Diagnostics
Compartment Syndrome: Diff by tense, “wood-like” extremity, pain out of proportion, and severe pain with passive muscle stretch. (May co-exist or develop after reperfusion).
Isolated Peripheral Nerve Injury: Diff by focal motor/sensory deficits (e.g., foot drop) but normal vascular assessment (ABI > 0.9, normal pulses).
Isolated Orthopedic Trauma: Diff by bony deformity, crepitus, and positive X-ray findings without vascular compromise.
Management
Stabilize (Primary Survey): ABCs. Control active hemorrhage with direct pressure. If direct pressure fails → apply a tourniquet proximal to the injury.
Surgical (Hard Signs): Immediate surgical exploration in the OR. Do not delay for imaging.
Algorithmic Approach (Soft Signs / Asymptomatic):
Measure ABI/API.
If ABI/API < 0.9 → CTA. (If CTA shows injury → Surgery or endovascular repair).
If ABI/API ≥ 0.9 → Serial physical exams + observation.
Adjunctive Care:
Update Tetanus prophylaxis.
IV Abx (e.g., Cefazolin) if there is an open fracture or gross contamination.
Fracture stabilization (splint/traction) if applicable.