Compartment syndrome

Definition

• Compartment syndrome is increased pressure within a closed muscle compartment that impairs local blood flow and causes ischemia.

Pathophysiology (brief)

• Increased intracompartmental pressure (ICP) compresses veins first, then arteries, reducing tissue perfusion and causing ischemia and nerve injury.
• Perfusion failure correlates with the difference between diastolic blood pressure and ICP: the delta pressure \(\Delta P = DBP - ICP\).
• Critical thresholds commonly used: absolute ICP > 30 mmHg or \(\Delta P < 30\ \text{mmHg}\), though clinical judgment matters.

Common causes / risk factors

• Long-bone fractures (especially tibial)
• Tight casts, dressings or splints
• Crush injuries, severe contusions
• Reperfusion after ischemia, burns, prolonged compression
• Bleeding into a compartment (anticoagulation)

Key clinical features — the "5 P's"

• Pain: severe, out of proportion to injury; pain on passive stretch of muscles is an early, important sign.
• Paresthesia: numbness or tingling from nerve ischemia.
• Pallor: pale skin distal to the compartment.
• Paralysis: weakness or loss of active movement (a late sign).

• Pulselessness: weak or absent pulses (a very late and unreliable sign).

• Also look for a tense, swollen compartment and increasing analgesic requirements.

Assessment and monitoring

• Perform frequent neurovascular checks: pain, sensation, motor function, pulses and capillary refill.
• Carefully monitor patients with casts or bulky dressings; consider loosening or bivalving a cast if compartment syndrome is suspected.
• Objective measurement: intracompartmental pressure monitoring with a needle manometer when diagnosis is unclear.
• Record and act on trends rather than a single reading; combine measurements with clinical signs.

Immediate management (priorities)

1. Remove constrictive dressings and open or cut the cast immediately.
2. Keep the limb at heart level (avoid excessive elevation) to preserve perfusion.
3. Provide analgesia and resuscitation as needed; give supplemental oxygen and IV fluids.
4. Obtain urgent surgical/orthopedic consultation — fasciotomy is definitive treatment.
5. Monitor for rhabdomyolysis (check CK, myoglobin, electrolytes) and treat hyperkalemia if present.

Definitive treatment

• Fasciotomy: surgical decompression of all involved compartments; delays cause irreversible muscle and nerve damage.

Complications of delayed treatment

• Muscle necrosis and fibrosis
• Permanent peripheral nerve injury
• Volkmann ischemic contracture
• Rhabdomyolysis with acute kidney injury
• Possible limb loss (amputation) in severe cases

Nursing & clinical tips

• Early recognition is vital: escalating pain despite analgesia and pain on passive stretch are high-yield signs.
• Never wait for loss of pulse to act — pulselessness is a late sign.
• Document neurovascular exams and time of any interventions (cast removal, measurements, consults).
• Educate staff and patients with casts to report increasing pain, numbness, or tightness immediately.

Quick checklist when suspecting compartment syndrome

• Remove or loosen constrictive device (cast/dressing)
• Neurovascular exam: pain, paresthesia, motor, pulses
• Measure compartment pressure if unclear
• Call surgeon for urgent fasciotomy
• Monitor for and treat systemic complications (rhabdomyolysis)

REMEMBER: Monitor for the signs and symptoms of compartment syndrome among patients wearing casts.