Compartment Syndrome — Recognition and Fasciotomy

Key Points

• Normal pulses do not exclude acute compartment syndrome.
• Escalating pain and pain with passive stretch are important early findings in an examinable patient.
• Remove constrictive casts and dressings immediately while arranging surgical evaluation.
• Pressure measurement supports diagnosis when the examination is unreliable or equivocal.
• A delta pressure of 30 mm Hg or less is commonly concerning but is not the only diagnostic criterion.
• Do not delay fasciotomy for advanced imaging when the diagnosis is clinically clear.
• Hypotension worsens tissue perfusion and can make a given compartment pressure more dangerous.
• Monitor for rhabdomyolysis, hyperkalemia, and AKI after decompression.

Algorithm

1. Identify a high-risk mechanism and perform a focused serial neurovascular examination.
2. Remove circumferential external compression and maintain the limb near heart level.
3. Correct hypotension and hypoxemia while calling orthopedic or trauma surgery immediately.
4. Measure compartment pressures when examination reliability is limited or findings are equivocal.
5. Proceed to urgent fasciotomy for established or strongly suspected acute compartment syndrome.
6. Decompress all affected compartments and assess muscle viability.
7. Monitor CK, potassium, renal function, urine output, and acid-base status after surgery.
8. Plan staged wound management, rehabilitation, and functional follow-up.

Clinical Synopsis & Reasoning

Common causes include tibial and forearm fractures, crush injury, reperfusion after limb ischemia, vascular injury, burns, tight casts or dressings, bleeding in anticoagulated patients, and prolonged limb compression. It can also occur without fracture. The pathophysiology is a cycle in which increased intracompartmental pressure reduces capillary perfusion, causing ischemia and edema that further raise pressure. Nerve and muscle injury becomes progressively less reversible with time, making repeated examination more important than waiting for dramatic late findings.

Pain out of proportion and pain with passive stretch are classic early clues in an awake patient, but analgesia, intoxication, sedation, regional anesthesia, neuropathy, or altered consciousness can obscure the examination. A tense compartment, paresthesia, and progressive motor deficit increase concern. Pulselessness and pallor are late signs and may indicate associated arterial injury; compartment syndrome commonly exists while distal pulses remain palpable because arterial pressure exceeds compartment pressure.

Intracompartmental pressure measurement is used when the examination is unreliable or equivocal. Absolute pressures and the delta pressure, calculated as diastolic blood pressure minus compartment pressure, support diagnosis. A delta pressure at or below about 30 mm Hg is commonly concerning in the right clinical context, but the 2025 AAOS guideline emphasizes integrating serial clinical findings and pressure data rather than relying on a single isolated number.

Treatment Strategy & Disposition

Immediately remove circumferential dressings, splints, or casts down to the skin while maintaining fracture alignment. Keep the limb roughly at heart level. Elevating it high above the heart can further reduce arterial perfusion; placing it far below the heart can worsen edema. Correct hypotension and hypoxemia because reduced systemic perfusion pressure lowers the gradient across the compartment. Give analgesia without allowing pain control to replace serial examination.

Urgent fasciotomy is definitive therapy for established acute compartment syndrome. All involved compartments must be adequately decompressed, and nonviable muscle may require debridement. Do not delay surgery for MRI or CT. Pressure measurements can clarify uncertain cases but should not postpone fasciotomy when the clinical diagnosis is clear and neurologic deficits are progressing. Reperfusion-related compartment syndrome can develop after embolectomy, vascular repair, or prolonged ischemia and requires the same urgency.

After decompression, monitor CK, potassium, creatinine, urine output, acid-base status, wound condition, and infection risk. Rhabdomyolysis and hyperkalemia can be substantial. Wounds are often left open initially and require staged closure, skin grafting, or repeated debridement. Functional recovery depends on the duration and severity of ischemia before decompression.

Epidemiology / Risk Factors

• Fractures, especially tibial shaft fractures, are common causes of acute extremity compartment syndrome.
• Young muscular patients can generate high intracompartmental pressures despite apparently minor trauma.
• Crush injury, vascular injury, anticoagulation, and reperfusion increase risk.
• Delayed diagnosis is more common when the patient cannot reliably report pain.
• Preventive monitoring protocols are important in high-risk orthopedic and trauma populations.

Investigations

Thresholds

Pharmacology

Prognosis / Complications

• Early fasciotomy can preserve limb function and prevent systemic complications.
• Delayed decompression can cause permanent nerve injury, muscle necrosis, contracture, infection, amputation, and death.
• Functional outcome depends heavily on ischemia duration before decompression.
• Rhabdomyolysis and AKI can complicate severe or delayed cases.
• Recovery may require multiple operations, wound closure procedures, and prolonged rehabilitation.

Patient Education / Counseling

• After injury or casting, return immediately for rapidly increasing pain, new numbness, weakness, or a feeling that the limb is becoming extremely tight.
• Do not insert objects under a cast or attempt to modify a surgical dressing without medical guidance.
• After fasciotomy, follow wound-care instructions closely and report fever, drainage, foul odor, or worsening pain.
• Attend physical and occupational therapy because stiffness and weakness can persist even after successful decompression.
• Maintain hydration and follow kidney testing recommendations after major rhabdomyolysis.
• Ask the surgical team about work, sports, and weight-bearing restrictions during recovery.

Notes

The 2025 AAOS acute compartment syndrome guideline reinforces serial clinical assessment and appropriate use of pressure measurement rather than a single-number diagnostic shortcut.

Compartment syndrome is a time-critical perfusion problem. The safe approach is early surgical involvement, repeated examination, and low tolerance for delay when neurologic function is deteriorating.

References

1. AAOS 2025 Acute Compartment Syndrome Clinical Practice Guideline — Link
2. American College of Surgeons Trauma Quality Programs — Link