Compartment syndrome happens when pressure builds inside a closed muscle compartment, usually after a fracture or crush injury, and cuts off blood flow to the muscles and nerves. It is a surgical emergency, because muscle can die within hours.
Key symptoms
- Severe pain out of proportion to the injury
- Pain that gets worse when the muscles are passively stretched
- Tight, full feeling in the limb
- Tingling or numbness; weakness comes later
What you find on exam
- Pain on passive stretch of the toes or fingers: the earliest sign
- Tense, firm compartment
- The 5 Ps: pain, paresthesia, pallor, paralysis, pulselessness
- Pulses are often present until late
Tests
- Diagnosis is mostly clinical
- Compartment pressure: a delta pressure (diastolic minus compartment) of 30 mm Hg or less supports it
- Creatine kinase, potassium and kidney function for muscle breakdown
Treatment basics
- Remove or split casts and tight dressings right away
- Keep the limb at heart level, not raised
- Urgent surgical fasciotomy
- IV fluids to treat rhabdomyolysis
Red flags
- Rising pain that needs more and more opioids
- Numbness or weakness in the limb
- Loss of pulse or a pale, cold limb
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Sources: NCCPA PANCE Content Blueprint; NBOME COMLEX-USA clinical presentations; AAMC Core Entrustable Professional Activities (Core EPAs). Written by Making Synapses. Making Synapses is not affiliated with these organizations.