What is the recommended management for acute compartment syndrome?

Management of Acute Compartment Syndrome

Emergent fasciotomy is the definitive treatment for acute compartment syndrome (ACS) when compartment pressure exceeds 30 mmHg or when the differential pressure (diastolic blood pressure minus compartment pressure) falls below 30 mmHg with clinical signs of ACS. 1

Immediate Recognition and Diagnosis

Clinical Presentation

• Pain out of proportion to injury is the earliest and most reliable clinical finding 2, 3
• Monitor for the "four P's": pain, pain with passive stretch, paresthesia, and paresis 1
• Avoid waiting for pulselessness and pallor—these are late signs indicating irreversible damage 1
• Clinical signs have low sensitivity but high negative predictive value 1

Diagnostic Thresholds

• ACS is defined as compartment pressure >30 mmHg OR differential pressure (diastolic BP - compartment pressure) <30 mmHg 1
• Measure compartment pressures every 30 minutes to 1 hour during the first 24 hours in high-risk patients 1
• Ischemic injury begins when tissue pressure reaches 10-20 mmHg below diastolic pressure 4

High-Risk Scenarios Requiring Vigilant Monitoring

• Fractures (especially tibial fractures) 1
• Crush injuries 1
• Hemorrhagic injuries or reperfusion of ischemic lesions 1
• Hypotension 1
• Circumferential burns or constrictive dressings 5

Initial Conservative Management (Before Fasciotomy Decision)

Immediate Actions

• Remove ALL constrictive dressings, casts, or splints immediately 5, 2
• Position the limb at heart level—avoid elevation as this decreases arterial perfusion pressure 2
• Optimize tissue perfusion by avoiding hypotension 2
• Apply cooling to the affected extremity 5

Analgesia Considerations

• Use motor-sparing regional anesthesia with low-concentration local anesthetics (0.1-0.25% bupivacaine or ropivacaine) if regional anesthesia is employed 6, 7
• Avoid dense blocks that eliminate all sensory function, as breakthrough pain is a critical warning sign 7
• Monitor motor function using straight-leg raising ability as a screening tool 6

Definitive Surgical Management

Indications for Fasciotomy

• Compartment pressure >30 mmHg with clinical signs of ACS 1
• Differential pressure (diastolic BP - compartment pressure) <30 mmHg 1
• Persistent symptoms despite removal of constrictive dressings and optimization of perfusion 2

Timing is Critical

• Muscles tolerate 4 hours of ischemia well, but damage becomes uncertain by 6 hours and irreversible after 8 hours 4
• Fasciotomy should be performed when tissue pressure rises to within 20 mmHg of diastolic pressure 4
• Early surgical stabilization involves wide incision of skin, subcutaneous tissue, and fascia 1

Surgical Technique

• Decompress ALL involved compartments—incomplete fasciotomy leads to continued ischemia 1, 2
• The muscle will initially swell outside the compartment but then recover as swelling reduces 5
• Plan for delayed primary closure or skin grafting after edema resolves 8

Post-Fasciotomy Management

Monitoring for Rhabdomyolysis

• Measure plasma creatine phosphokinase (CPK), myoglobin, and potassium levels serially 1
• CPK levels >75,000 IU/L are associated with >80% incidence of acute kidney injury 1
• Plasma myoglobin has earlier peak concentration than CPK and may be more sensitive for detecting kidney injury risk 1
• Monitor hourly urine output via bladder catheterization 1

Fluid Resuscitation for Rhabdomyolysis

• Administer >6L of fluid in patients with severe rhabdomyolysis (CPK >15,000 IU/L) to prevent acute kidney injury 1
• Moderate rhabdomyolysis requires 3-6L per day 1
• Maintain urine pH ≥6.5 1
• Earlier initiation of volume resuscitation is associated with lower rates of acute kidney injury 1

Wound Management

• Re-exploration within 24-48 hours after initial fasciotomy 8
• Debride necrotic muscle and tissue at each re-exploration 8
• Continue wound care until definitive closure is possible 8

Critical Pitfalls to Avoid

• Never attribute prolonged motor block (>24 hours) solely to regional anesthesia—this delays ACS diagnosis 6
• Do not wait for absent pulses or pallor before intervening—these indicate irreversible damage 1
• Avoid elevation of the affected limb above heart level, as this decreases perfusion pressure 2
• Do not rely solely on clinical examination—compartment pressure measurement is the most reliable test when diagnosis is uncertain 3
• Never delay fasciotomy for imaging studies if clinical suspicion is high 2

Special Populations

Pediatric Considerations

• Normal compartment pressures are higher in children (13-16 mmHg) compared to adults (0-10 mmHg) 7
• Use the "three As" for diagnosis in young children who cannot articulate symptoms: anxiety, agitation, and analgesic requirement 7
• Incidence after pediatric trauma is 0.02%, with highest risk in ages 12-19 years 7

Trauma Patients

• Motorcyclists with lower extremity injuries are a high-risk group 5
• Even relatively minor mechanisms can produce ACS—educate all injured patients to seek care for numbness, deep pain, or coolness 5