A 28-year-old male presents to the emergency department 6 hours after a crush injury to his left leg sustained in a motor vehicle accident. On examination, he has severe pain out of proportion to the clinical findings, pain with passive dorsiflexion of the foot, and tense swelling of the anterior tibial region. Sensory examination reveals diminished sensation over the dorsum of the foot. Pedal pulses are palpable bilaterally. What is the most appropriate immediate management?

Explanation

## Clinical Diagnosis: Acute Compartment Syndrome **Key Point:** Compartment syndrome is a surgical emergency requiring fasciotomy within 6–8 hours of symptom onset to prevent irreversible tissue necrosis and systemic complications. ### Classic Presentation The patient exhibits the **"5 P's"** of compartment syndrome: 1. **Pain** — out of proportion to clinical injury (most sensitive and earliest sign) 2. **Pain with passive stretch** — passive dorsiflexion causes severe pain (pathognomonic) 3. **Paresthesia** — diminished sensation over dorsum of foot (nerve ischemia) 4. **Pallor** — tense swelling (tissue edema) 5. **Pulselessness** — late finding; pulses may still be present early **High-Yield:** Preserved pulses do NOT exclude compartment syndrome. Arterial pressure exceeds compartment pressure initially; venous and capillary flow ceases first. ### Why Fasciotomy Is Urgent Compartment pressure rises rapidly after crush injury. Muscle becomes ischemic when compartment pressure approaches diastolic blood pressure. Irreversible damage occurs within 6–8 hours: - Muscle necrosis → rhabdomyolysis → hyperkalemia, myoglobinuria, acute kidney injury - Nerve ischemia → permanent sensorimotor deficit - Tissue loss → contracture and functional impairment **Clinical Pearl:** Fasciotomy should NOT be delayed for imaging (CT, MRI) or compartment pressure measurement in a clinically obvious case. Clinical diagnosis is sufficient. ### Why Other Options Fail | Option | Why Wrong | | --- | --- | | Elevation + ice | Conservative measures do not relieve compartment pressure; delays definitive treatment and allows irreversible damage. | | IV fluids + observation | Observation is contraindicated in acute compartment syndrome; 6 hours is already at the threshold of irreversibility. | | Amputation | Premature; fasciotomy preserves limb viability if performed urgently. Amputation is a last resort after failed fasciotomy or established gangrene. | **Warning:** Do not confuse compartment syndrome with simple crush injury or contusion. The key discriminator is pain out of proportion and pain with passive stretch.