Acute Compartment Syndrome

November 16, 2023

INTRODUCTION OF ACS

Compartment syndrome is a painful and potentially limb threatening medical emergency which requires early diagnosis and management to prevent serious complications.

Compartment syndrome occurs when increased pressure within the facial compartment compromises the circulation and function of the tissues within that section. Increases pressure within the compartments of tissue within the limbs can be caused trauma which caused swelling and/internal bleeding. Compartment syndrome may occur acutely (following trauma) or chronically as a syndrome affecting athletes.

CAUSES AND RISKS OF ACUTE COMPARTMENT SYNDROME

ACS most often develops soon after significant trauma particularly involving long bone fractures (accounts for 75% of incidents of ACS). Examples of trauma which can increase compartment pressure include:

Forceful direct trauma to tissue compartment (e.g. crush injury)
Severe thermal burns
Constrictive bandages, splints or casts
Penetrating trauma
High pressure injection
Injury to vascular structures
Animal bites and stings
Open and closed bone fractures

ACS may also occur following non-traumatic causes including any condition that raises the intercompartmental pressure and places the patient at risk for developing compartment syndrome.

Most common sites are the leg and forearm while other sites include foot, thigh and gluteal regions. The discussion below will focus on the leg and forearm.

ACS is more often seen in patients under 35 years, and this is thought to be due to the increased muscle mass of this age group.

ANATOMIC COMPARTMENTS

ACS can occur in any distinct anatomic compartment bound by fascial membranes. It has been recorded in the upper and lower limbs, hand, foot, buttock, abdomen and thorax.

The Lower Leg

The lower leg is the most common site and is comprised of four compartments: anterior, lateral, deep posterior and superficial posterior.

Anterior compartment is the most common site for ACS. Signs of ACS affecting the anterior compartment include:
- Loss of sensation between the first and second toes
- Weakness of foot dorsiflexion
- Later signs include foot drop, claw foot and deep peroneal dysfunction.
Lateral compartment contains muscles responsible for foot eversion and some plantarflexion. Increased pressure in this area may result in:
- Deep peroneal nerve deficit (weakness in dorsiflexion and eversion of the foot)
- Sensory loss between first and second toes
- Altered sensation to the lower leg and the dorsum of the foot
Deep posterior compartment contains muscles that assist with plantarflexion along with the posterior tibial artery, peroneal artery and the tibial nerve. Increased pressure may result in:

Plantar hypesthesia
Weakness of toe flexion
Pain on passive extension of toes

Superficial posterior compartment contains major muscles of ankle plantarflexion. There are no major arteries or nerves in this compartment. It is also the compartment least likely to develop ACS. Increased pressure will result in pain and tenderness.

The Forearm

The forearm is comprised of 4 compartments: deep and superficial volar compartments, dorsal compartment and mobile wad (lateral).

The volar compartment is at highest risk of ACS following trauma. It contains the digital flexors.

CLINICAL FEATURES OF ACS

Signs and symptoms generally appear in graduated fashion although timings can vary.

Symptoms of ACS can include the following:

Pain out of proportion to apparent injury (early and common)
Persistent deep ache or burning pain
Paraesthesia (onset within approximately 30 mins to 2 hours)

Examination findings suggestive of ACS include the following:

Pain with passive stretch of muscles of muscles in the affected compartment
Tense compartment with a firm “wood-like” feeling
Pallor from vascular insufficiency
Diminished sensation
Muscle weakness (onset within approximately 2-4 hours of ACS
Paralysis

Muscle weakness can be difficult to assess in traumatised patients, and those receiving sedating medications, those with altered mental status and may be attributable to pain, fracture, soft tissue injury, peripheral or central nerve injury or ACS.

DIAGNOSIS OF ACUTE COMPARTMENT SYNDROME

Compartment pressure measurements are an important adjunct in the diagnosis of ACS.

Whenever possible, the surgeon responsible for determining treatment options should also determine the need for compartment pressure measurements where clinically indicated.

In rural and remote areas and hospitals with limited surgical coverage, measuring compartmental pressure may not always be possible.

Instruments used to measure compartment pressures:

Handheld manometer – used most often as it is portable, simple and relatively accurate
Simple needle manometer system
The wick or slit catheter technique

Magnetic resonance imaging (MRI) or Near infrared spectroscopy could also be considered as diagnostic tools to assess volume, pressure and perfusion of affected limbs.

TREATMENT AND MANAGEMENT OF ACS

Immediate management of suspected ACS includes relieving all external pressure on the compartment. The limb should neither be elevated nor placed in a dependant position. Placing the limb level with the heart helps to avoid reductions in arterial inflow and increases in compartment pressures from dependent swelling both of which can exacerbate limb ischaemia.

Pain should be assessed managed by administering analgesics, and supplementary oxygen provided.

Hypotension reduces perfusion, exacerbating tissue injury and should be treated with boluses of intravenous isotonic saline.

Surgical treatment of ACS involves a fasciotomy, where skin is cut open longitudinally along the facial lines to immediately relieve internal pressure and allow reperfusion of tissue. Fasciotomy to fully decompress all involved compartments is the definitive treatment for ACS in the great majority of cases.

Treatment of the fracture should be considered as soon as possible and patients must be monitored for signs of ACS following these procedures.

Vascular bleeding, particularly arterial, increases compartment pressures and muscle deprived of arterial blood flow becomes ischaemic and prone to perfusion injury, causing swelling and a further increase in compartment pressures.

If left untreated ACS can result in muscle necrosis, sensory deficits, paralysis, infection, fracture non-union and limb amputation.

NURSING MANAGEMENT

Nursing priorities of the patient with ACS includes managing the following:

Pain assessment and management
Assessment of peripheral perfusion
Supporting patient mobility

CONCLUSION

Early assessment, diagnosis and appropriate nursing and surgical management of ACS generally produces good functional and cosmetic results and limits loss of permanent nerve and muscle damage.