A 28-year-old male construction worker sustains a crush injury to his right leg when a concrete slab falls on him. He is brought to the emergency department 2 hours post-injury with severe pain in the anterior compartment of the leg, disproportionate to clinical findings. On examination, the leg is swollen and tense. Passive dorsiflexion of the foot elicits severe pain. Peripheral pulses are palpable and sensation is intact. Compartment pressure measurement shows 65 mmHg. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis: Acute Compartment Syndrome **Key Point:** This patient presents with the classic pentad of compartment syndrome: pain out of proportion to injury, pain with passive stretch (passive dorsiflexion), swelling, paresthesias (or intact sensation early), and pulselessness (late finding). Pulses being present does NOT exclude compartment syndrome — pulses are preserved until late stages. **High-Yield:** The pathognomonic sign is **pain with passive stretch of muscles in the affected compartment**. In anterior compartment syndrome, passive dorsiflexion causes severe pain. ### Compartment Pressure Interpretation | Pressure (mmHg) | Clinical Significance | | --- | --- | | < 10 | Normal | | 20–30 | Elevated, monitor closely | | > 30 (or within 30 of diastolic BP) | Surgical emergency | | 65 | **Diagnostic of compartment syndrome** | **Key Point:** A compartment pressure of 65 mmHg is well above the threshold for surgical intervention. The critical threshold is typically **30 mmHg absolute pressure** or **within 30 mmHg of the patient's diastolic blood pressure** (Δ P = DBP − compartment pressure < 30 mmHg). ### Management Algorithm ```mermaid flowchart TD A[Suspected Compartment Syndrome]:::outcome --> B{Clinical signs present?}:::decision B -->|Pain with passive stretch + swelling| C[Measure compartment pressure]:::action C --> D{Pressure > 30 mmHg or<br/>DBP - CP < 30?}:::decision D -->|Yes| E[Emergency Fasciotomy]:::urgent D -->|No| F[Conservative management<br/>+ serial reassessment]:::action E --> G[Prevent muscle necrosis<br/>& rhabdomyolysis]:::outcome ``` **Clinical Pearl:** Compartment syndrome is a **surgical emergency**. Waiting for all five signs (including pulselessness) results in irreversible muscle necrosis, rhabdomyolysis, acute kidney injury, and permanent disability. Early fasciotomy within 6–8 hours of symptom onset prevents these complications. **Warning:** Presence of pulses does NOT exclude compartment syndrome. Arterial perfusion pressure exceeds venous pressure until very late; by then, muscle is already necrotic. **Mnemonic — 5 P's of Compartment Syndrome:** Pain (out of proportion), Pressure (elevated), Paresthesias, Pallor, Pulselessness (late). The first three are most reliable. ## Why This Answer Is Correct With a compartment pressure of 65 mmHg (far exceeding the 30 mmHg threshold) and classic clinical signs, **emergency fasciotomy is the standard of care**. Delay risks irreversible muscle necrosis and systemic complications (rhabdomyolysis, hyperkalemia, acute kidney injury, death).