Compartment syndrome
Background
- Consider whenever pain and paresthesia occur in an extremity after a fracture
- Immediate threat is viability of nerve and muscle; later threat is infection, gangrene, rhabdo, renal failure
Pathophysiology
- Tissue perfusion is difference between diastolic BP and compartment pressure
- As compartment pressure increases, tissue perfusion decreases
Etiology
- Most commonly caused by tibia fracture (anterior compartment)
- Usually develops soon after significant trauma
- May be delayed up to 48hr after the event
- Causes:
- Orthopedic
- Tibial fractures
- Forearm fractures
- Vascular
- Ischemic-reperfusion injury
- Hemorrhage
- Iatrogenic
- Vascular puncture in anticoagulated patients
- IV/intra-arterial drug injection
- Constrictive casts
- Soft tissue injury
- Prolonged limb compression
- Crush injury
- Burns
Clinical Features
- Pain
- Severe, out of proportion to physical findings
- Worse w/ passive movement (this extends the muscle -> incr in volume -> incr pressure)
- Paresthesia
- Occurs in sensory distribution of affected nerve
- Compartment is swollen, firm, tender w/ squeezing
- 5 P's (pain, paresthesias, pallor, pulselessness, paralysis)
- Classic signs of disruption in arterial flow, not of compartment syndrome
- Only found once arterial flow has stopped (very late finding)
- Classic signs of disruption in arterial flow, not of compartment syndrome
Diagnosis
- Compartment Pressure
- Normal is <10
- Pressures <30 can be tolerated w/o significant damage
- Exact level of pressure elevation that causes cell death is unclear
- "Delta Pressure" may be better predictor than absolute pressure value
- Diastolic BP - intracompartmental pressure
- Once this value is <30 compartment syndrome is likely
- Diastolic BP - intracompartmental pressure
Work-Up
- Compartment pressure (take serial measurements if needed)
- Total CK, UA (rhabdo)
- Chemistry (hyperkalemia)
Specific Syndromes
Lower Leg
- Anterior
- Nerve: Deep fibular (peroneal)
- Sensation of 1st webspace
- Muscle: tibialis anterior
- Foot/ankle dorsiflexion
- Nerve: Deep fibular (peroneal)
- Lateral
- Nerve: Superficial fibular (peroneal) nerve
- Sensation of lateral aspect of lower leg, dorsum of foot
- Muscle: Peroneus
- Foot plantarflexion
- Nerve: Superficial fibular (peroneal) nerve
- Deep posterior
- Nerve: Posterior tibial nerve
- Sensation of plantar aspect of foot
- Muscle: Flexor hallucis/digitorum longus
- Pain with passive extension of the toes
- Nerve: Posterior tibial nerve
- Superficial posterior
- Nerve: Sural cutaneous nerve
- Sensation of lateral aspect of foot
- Muscle: Gastrocnemius
- Weakness of plantarflexion
- Nerve: Sural cutaneous nerve
Hand
- Crush injury, w/ or w/o associated fracture
- Involved compartments: thenar, hypothenar, adductor pollicis, and 4 interossei muscles
- Diagnosis
- Clinical, not based on actual compartment pressure
- Pain
- Deep, constant, poorly localized, out of proportion to exam
- "Intrinsic minus" position at rest
- MCP joint extended w/ proximal IP joint slightly flexed
- Pain w/ passive stretch of involved compartmental muscles
- Interosseus: performed w/ MCP joint extended and PIP jionts fully flexed
- Thenar, hypothenar: performed by extension of MCP joint
- Tense swelling of affected compartment
Forearm
- Associated w/ supracondylar fx (peds), distal radius fx (adults)
- Compartments
- Dorsal (highest risk)
- Volar
Other
- Thigh (quadriceps compartment)
- Buttock (gluteal compartment)
- Arm (deltoid, biceps compartments)
- Abdominal
Treatment
- Fasciotomy
- Perform as soon as diagnosis is made by history/physical or by measurement
- Permanent damage results from >8hr of ischemia
- Support the blood pressure in the hypotensive pt
- Place affected limb at the level of the heart or slightly dependent
- AVOID ice (will further compromise microcirculation)
- Bivalve or remove cast if present
Source
- Tintinalli
- Rosen's