II. Epidemiology
-
Incidence
- Men: 7.3 per 100,000
- Women: 0.7 per 100,000
- Mean age: 30 to 44 years old (esp. men)
III. Causes: Trauma (70%)
- Burn Injury
- Fracture (most common)
- Crush injury
- Hemorrhage (esp. vascular injury, on Anticoagulants, Bleeding Disorder)
- Prolonged application of MAST trousers (PASG)
- Snake Bite
IV. Causes: Nin-Trauma (30%)
- Deep Vein Thrombosis
- Prolonged extremity compression (tight cast or splint)
- Blood Flow Restored in previously ischemic limb
- IV Contrast Extravasation
- Infection
- Malignancy
- Drug Overdose
V. Pathophysiology: Mechanism
- Extremity Trauma increases interstitial tissue pressure (due to factors listed above)
- Increased pressure occurs in fixed fascial compartment
- Tissue pressure rises above that of capillaries
- Blood Flow distal to high tissue pressures is cut off
- Ischemic Muscle and tissue become hypoxic and generate acidosis with secondary increased capillary permeability
- Further fluid extravasation into compartment further increases pressure
- Distal nerve (in first 12 hours) and Muscle (in first 3-4 hours) become ischemic and necrose
VI. Pathophysiology: Compartments
-
Thigh, Leg or foot
- Anterior Compartment (between anterior tibial and fibula)
- Lateral Compartment (anterolateral to fibula)
- Superficial Posterior Compartment (posterior leg superficial to neurovascular structures)
- Deep Posterior Compartment (posterior leg deep to neurovascular structures)
-
Forearm (3 compartments)
- Volar (wrist flexors, Median Nerve and Ulnar Nerve)
- Dorsal (wrist extensors, finger extensors)
- Mobile wad (Muscle bodies)
- Hand (10 compartments)
- Hypothenar compartment
- Thenar compartment
- Adductor pollicis compartment
- Four dorsal interossei compartments
- Three volar interossei compartments
VII. Risk Factors: Regions
- Tibial Shaft Fractures
- Compartment Syndrome complicates 3-5% of adult tibial shaft Fractures
- Although uncommon <12 years, tibial shaft Fracture accounts for 40% of childhood cases
- Malhotra (2015) Injury 46(2): 254-8 +PMID: 24972494 [PubMed]
- Other common compartments
- Forearm and Hand
- Less common areas of Compartment Syndrome
- Thigh
- Buttock
- Upper arm
VIII. Symptoms
- Presentation within first 24-48 hours from time of causative event (e.g. injury)
- Severe extremity pain out of proportion to injury
- This is the only consistent finding in Compartment Syndrome
- Paresthesias or Anesthesia to light touch
- Mnemonic: "6 Ps" (unreliable in young or non-verbal patients)
- Pain
- Pressure (pain on palpation)
- Paresthesia
- Paresis or paralysis (late sign)
- Pallor (late sign)
- Pulseless (last sign to occur)
- Mnemonic: "3 As" (in young children)
IX. Signs
- Pain or Paresthesias at rest worse with passively Stretching, extension of involved Muscles
- Passive finger or toe range of motion
- Patient flexes injured extremity to reduce pain
- Pain is out of proportion to level of injury and may be refractory to Analgesics
- Test Sensitivity 93% (98% if Muscle Weakness is also present)
- Decreased Sensation of involved nerves
- Vibratory Sensation lost first
- Tense extremity swelling or firm compartment
- Test Sensitivity <50% for Compartment Syndrome
- Less reliable signs of Compartment Syndrome (and consider arterial injury or thrombosis in Trauma)
- Distal pulses may be diminished (late sign of Compartment Syndrome)
- Occlude collateral circulation when assessing
- Distal extremity pallor may be present
- Distal pulses may be diminished (late sign of Compartment Syndrome)
- Specific extremity neurologic function
- Motor Exam
- Ulnar Nerve: Claw Hand
- Radial Nerve: Wrist Drop
- Median Nerve: Cannot make OK Sign
- Peroneal Nerve: Foot Drop
- Consider Anterior Tibial Compartment Syndrome
- Sensory Exam
- Radial Nerve: thumb web space
- Median Nerve: distal index
- Ulnar Nerve: distal pinky
- Motor Exam
- Bunnel Test (stretch test)
- Examiner maintains the MCP joints in extension
- Actively or passively flex the interphalangeal joints (PIP and DIP joints)
- Findings suggestive of Compartment Syndrome
- Restricted PIP and DIP joint range of motion when MCP joints are held in extension
- PIP and DIP joint range of motion are not restricted when MCP joint is allowed to fall into flexion
X. Diagnosis
-
Intracompartmental Pressure Monitor (gold standard)
- Have a low threshold for checking Compartment Pressures (esp in pain out of proportion)
- Normal Compartment Pressures
- Adult: 8-10 mmHg
- Children: 10-15 mmHg
- Diagnostic criteria
- Compartment Pressure >30 mmHg OR
- Delta-P (Diastolic pressure - Compartment Pressure) <30 mmHg
- Delta-P <30 mmHg for >2 hours is highly accurate for Compartment Syndrome
- McQueen (2013) J Bone Joint Surg Am 95(8): 673-7 [PubMed]
- Near-Infrared Spectroscopy (NIRS, experimental)
- Noninvasive spectroscopy (akin to Pulse Oximetry)
- Detects hemoglobin Oxygen Saturation at 2-3 cm depth under the skin
- Oxygen Saturation is markedly reduced in Compartment Syndrome
- Technique limited by body habitus and subcutaneous fat
- Cole (2014) J Trauma Treatment S2:003 [PubMed]
XI. Differential Diagnosis: Acute Extremity Pain out of Proportion
XII. Labs
- Serum Chemistry Panel (esp. Renal Function)
-
Creatine Kinase (CK)
- Compartment Syndrome is associated with Rhabdomyolysis in 40% of cases
XIII. Imaging: Differential diagnosis evaluation
- Extremity CT arteriography
- Evaluate for arterial injury or thrombosis
XIV. Precautions
- Irreversible damage occurs in 4-6 hours
- Do not wait for pallor or pulselessness
- Compartment Syndrome can occur with open Fractures
XV. Management
- Consult orthopedic surgery emergently
-
General Measures
- Pain management with Opioid Analgesics
- Fluid Resuscitation
- Remove any external compression
- Reduce Fractures and dislocations
- Raise affected limb over heart level
- Pressures consistent with Compartment Syndrome
- Tissue pressure >30 mmHg
- Some use tissue pressure >15 mmHg if symptoms and signs are present
- Delta Pressure (Diastolic Pressure - Tissue Pressure) <30 mmHg
- Tissue pressure >30 mmHg
-
Fasciotomy
- See Burn Escharotomy
- Indications
- Tissue pressure exceeds 30-45 mmHg
- Tissue pressure within 20 mmHg of Diastolic BP
- Technique: Leg
- Two longitudinal Incisions (each 15-18 cm long, at least 8 cm apart)
- Anterolateral Incision (avoiding superficial peroneal nerve)
- Posteromedial Incision (avoiding saphenous vein and saphenous nerve)
XVI. Course
- Compartment Syndrome develops hours after injury
XVII. References
- Blythe, Gray and Delasobera (2018) Crit Dec Emerg Med 32(7):3-9
- Long and Gottlieb in Herbert (2021) EM:Rap 21(6):12-3
- Mason, Farah, Inaba in Herbert (2018) EM:Rap 18(6):17
- Gardiner (2018) Crit Dec Emerg Med 37(5): 3-14
- (1993) ATLS Providers Manual, p. 234-5
- Geiderman in Marx (2002) Rosen's Emerg. Med, p. 478-80
- Hori (2015) Crit Dec Emerg Med 29(3): 2-7
- Warrington (2019) Crit Dec Emerg Med 33(12): 16-17