Continuing Education Activity

Acute compartment syndrome is a condition in which there is increased pressure within a closed osteofascial compartment, resulting in impaired local circulation. Without prompt treatment, acute compartment syndrome can lead to ischemia and eventually, necrosis. This activity reviews the evaluation and management of acute compartment syndrome and highlights the role of the interprofessional team in caring for patients with this condition.

Objectives:

• Identify the body parts most commonly affected by acute compartment syndrome and the expected corresponding symptoms.
• Explain how to evaluate a patient for acute compartment syndrome.
• Outline how to treat acute compartment syndrome.
• Review the need for a well-integrated, well-coordinated interprofessional team approach when caring for patients with acute compartment syndrome.

Introduction

Acute compartment syndrome occurs when there is increased pressure within a closed osteofascial compartment, resulting in impaired local circulation. Acute compartment syndrome is considered a surgical emergency since, without proper treatment, it can lead to ischemia and eventually necrosis. Generally, acute compartment syndrome is considered a clinical diagnosis. However, intracompartmental pressure (ICP) > 30 mmHg can be used as a threshold to aid in diagnosis. However, a single normal ICP reading does not exclude acute compartment syndrome. 

Fascia is a thin, inelastic sheet of connective tissue that surrounds muscle compartments and limits the capacity for rapid expansion. In the leg, there are four muscle compartments: anterior, lateral, deep posterior, and superficial posterior. The anterior compartment of the leg is the most common location for compartment syndrome. This compartment contains the extensor muscles of the toes, the tibialis anterior muscle, the deep peroneal nerve, and the tibial artery. 

Other locations in which acute compartment syndrome is seen include the forearm, thigh, buttock, shoulder, hand, and foot. It can also be seen in the abdomen, but more commonly, it presents in the limbs. [1][2][3][4][5]

Significant attention should be paid to patients with open fractures. Recent retrospective studies indicate that skin laceration would not relieve the pressure inside the muscle compartments. Therefore, acute compartment syndrome is still predictable. This is especially pertinent for open Gustilo type 2 and 3 lesions in proximal intra-articular tibia fractures.[6]

Etiology

Acute compartment syndrome can occur with any condition that restricts the intracompartmental space or increases the fluid volume in the intracompartmental space. Acute compartment syndrome can occur without any precipitating trauma but typically occurs after a long bone fracture, with tibial fractures being the most common cause of the condition, followed by distal radius fractures. Seventy-five percent of cases of acute compartment syndrome are associated with fractures. After fractures, the most common cause of acute compartment syndrome is soft tissue injuries. Other causes of acute compartment syndrome include burns, vascular injuries, crush injuries, drug overdoses, reperfusion injuries, thrombosis, bleeding disorders, infections, improperly placed casts or splints, tight circumferential bandages, penetrating trauma, intense athletic activity, and poor positioning during surgery. 

In children, supracondylar fractures of the humerus and both ulnar and radial forearm fractures are associated with compartment syndrome. [7][8][9][10][5][11]

Epidemiology

The incidence of acute compartment syndrome is estimated to be 7.3 per 100,000 in males and 0.7 per 100,000 in females, with the majority of cases occurring after trauma. Tibial shaft fracture is the most common cause of acute compartment syndrome, is associated with a 1 to 10 percent incidence of acute compartment syndrome.

Acute compartment syndrome occurs more commonly in males younger than 35, which may be due to a larger relative intracompartmental muscle mass and increased likelihood of being involved in high-energy trauma.

Patients with bleeding diathesis, such as hemophilia, are at greater risk for acute compartment syndrome. Cases of acute compartment syndrome have been reported without acute precipitating trauma in pediatric leukemia. [4][5][12][13][11][14]

Patients who develop acute compartment syndrome without any fracture are at a higher risk of developing complications and delayed treatment.[15]

Pathophysiology

Acute compartment syndrome occurs due to decreased intracompartmental space or increased intracompartmental fluid volume because the surrounding fascia is inherently non-compliant. As the compartment pressure increases, hemodynamics are impaired. There is normally an equilibrium between venous outflow and arterial inflow. When there is an increase in compartmental pressure, there is a reduction in venous outflow. This causes venous pressure and, thus, venous capillary pressure to increase. If the intracompartmental pressure becomes higher than arterial pressure, a decrease in arterial inflow will also occur. The reduction of venous outflow and arterial inflow result in decreased oxygenation of tissues causing ischemia. If the deficit of oxygenation becomes high enough, irreversible necrosis may occur.

The normal pressure within a compartment is less than 10 mmHg. If the intracompartmental pressure reaches 30 mmHg or greater, acute compartment syndrome is present. However, a single normal ICP reading does not exclude acute compartment syndrome. ICP should be monitored serially or continuously. [16][17][18]

History and Physical

Acute compartment syndrome typically occurs within a few hours of inciting trauma. However, it can present up to 48 hours after. The earliest objective physical finding is the tense, or ''wood-like" feeling of the involved compartment. Pain is typically severe, out of proportion to the injury. Early on, pain may only be present with passive stretching. However, this symptom may be absent in advanced acute compartment syndrome. In the initial stages, pain may be characterized as a burning sensation or as a deep ache of the involved compartment. Paresthesia, hypoesthesia, or poorly localized deep muscular pain may also be present.

Classically, the presentation of acute compartment syndrome has been remembered by "The Five P's": pain, pulselessness, paresthesia, paralysis, and pallor. However, aside from paresthesia, which may occur earlier in the course of the condition, these are typically late findings. Beware that the presence or absence of a palpable arterial pulse may not accurately indicate relative tissue pressure or predict the risk for compartment syndrome. In some patients, a pulse is still present, even in a severely compromised extremity. 

Physical exam should focus on the neurovascular territory of the involved compartment:

• Observe skin for lesions, swelling, or color change
• Palpate over the compartment, observing temperature, tension, tenderness
• Check pulses
• Evaluate two-point discrimination and sensation
• Evaluate motor function

Although the clinical features discussed above can help identify compartment syndrome, they have limited sensitivity and specificity. Other factors, such as compartment pressures, can help make the diagnosis.[19][20]

Due to the potential for rapid progression of compartment syndrome, clinicians should perform serial exams. 

Evaluation

 Acute compartment syndrome is a clinical diagnosis and needs prompt treatment. However, the following are done to evaluate further and to confirm the diagnosis. 

• Radiographs should be obtained if a fracture is suspected
• Measurement of intracompartmental pressure is not required but can aid in diagnosis if uncertainty exists. Compartment pressures are often measured with a manometer, a device that detects intracompartmental pressure by measuring the resistance that is present when a saline solution is injected into the compartment. Another method employs a slit catheter, whereby a catheter is placed within the compartment, and the pressure is measured with an arterial line transducer. The slit catheter method is more accurate and allows for continuous monitoring. Its use is also recommended to measure all the surrounding compartments.
  • The normal pressure within the compartment is between 0 mmHg to 8 mmHg.
  • An intra-compartmental pressure greater than 30 mmHg indicates compartment syndrome and a need for fasciotomy.[21]
  • When intra-compartmental pressure increases to within 10 mmHg to 30 mmHg of the patient's diastolic blood pressure, this indicates inadequate perfusion and relative ischemia of the involved extremity.
  • The perfusion pressure of a compartment, also known as the compartment delta pressure, is defined as the difference between the diastolic blood pressure and the intra-compartmental pressure:
    • delta pressure = diastolic pressure - measured intracompartmental pressure
    • clinicians often utilize delta pressure less than or equal to 30 mmHg as indicative of the need for fasciotomy.
• Ultrasound with Doppler can be used to look for occlusion or thrombus.
• Elevations in creatine phosphokinase (CPK) may suggest muscle breakdown from ischemia, damage, or rhabdomyolysis.
  • If rhabdomyolysis is being considered, renal function tests, urine myoglobin, and urinalysis should be done.
  • If rhabdomyolysis is diagnosed, a chemistry panel is needed.
• Preoperative studies should, at a minimum, include a complete blood count and coagulation studies. [22][23][24][25]

Treatment / Management

Acute compartment syndrome is an emergency condition. Less time should be spent on confirmation of the diagnosis, as delayed treatment may result in loss of limb.[26]

• Immediate surgical consult
• Provide supplemental oxygen.
• Remove any restrictive casts, dressings, or bandages to relieve pressure.
• Keep the extremity at the level of the heart to prevent hypo-perfusion.
• Prevent hypotension and provide blood pressure support in patients with hypotension.
• If ICP is greater than or equal to 30 mmHg or delta pressure is less than or equal to 30 mmHg, fasciotomy should be done.

For patients who do not meet diagnostic criteria for acute compartment syndrome but who are at high risk based on history and physical exam findings, or for patients with intracompartmental pressures between 15 to 20 mmHg, serial intracompartmental pressure measurements are recommended. Patients with ICPs between 20-30 mmHg should be admitted and the surgical team should be consulted. For patients with intracompartmental pressures greater than 30 mmHg or delta pressures less than 30 mmHg, surgical fasciotomy should be done.

Acute compartment syndrome is a surgical emergency, so prompt diagnosis and treatment are critical. Once the diagnosis is confirmed, immediate surgical fasciotomy is needed to reduce the intracompartmental pressure. The ideal timeframe for fasciotomy is within six hours of injury, and fasciotomy is not recommended after 36 hours following injury. When tissue pressure remains elevated for that amount of time, irreversible damage may occur, and fasciotomy may not be beneficial in this situation.

If necrosis occurs before fasciotomy is performed, there is a high likelihood of infection which may require amputation. If infection occurs, debridement is necessary to prevent systemic spread or other complications.

After a fasciotomy is performed and swelling dissipates, a skin graft is commonly used for incision closure. Patients must be closely monitored for complications which include infection, acute renal failure, and rhabdomyolysis. [2][1][27]

Differential Diagnosis

• Deep vein thrombosis
• Cellulitis
• Gas gangrene
• Phlegmasia cerulean dolens
• Rhabdomyolysis
• Cnidaria envenomation
• Peripheral vascular injuries

Pertinent Studies and Ongoing Trials

There are ongoing clinical trials on the treatment of compartment syndrome with ultrafiltration. The study consists of patients with tibial shaft fractures that need surgical correction and are at risk of developing compartment syndrome. It involves the insertion of ultrafiltration catheters in the tissue of the muscle compartment to monitor the biochemical environment inside the tissues of the compartment. The trial also studies that the repetitive insertion of the catheters is safe and does not increase the intercompartmental pressure. The study is being done by the national institute of arthritis and musculoskeletal and skin diseases (NIAMS). Previous studies on ultrafiltration as a treatment modality for compartment syndrome have been done but further research on this approach is warranted.[28]

Prognosis

The prognosis after treatment of compartment syndrome depends mainly on how quickly the condition is diagnosed and treated. When fasciotomy is done within 6 hours, there is almost 100% recovery of limb function. After 6 hours, there may be residual nerve damage. Data show that when the fasciotomy is done within 12 hours, only two-thirds of patients have normal limb function. In very delayed cases, the limb may require an amputation.

Outcomes for the posterior compartment syndrome of the leg are worse than outcomes for the anterior compartment of the leg since it is difficult to perform inadequate decompression of the posterior compartment. Long-term studies on survivors do reveal residual pain, Volkmann's contracture, mild neurological deficits, and marked cosmetic defects in the affected extremity. Recurrent compartment syndrome has been known to occur in athletes due to scarring. There are some individuals who may die from acute compartment syndrome. Often these cases are caused by infection, which ultimately leads to sepsis and multiorgan failure. [29][5][30][31]

Complications

 The following are the complications of compartment syndrome:

• Pain
• Contractures
• Rhabdomyolysis
• Nerve damage and associated numbness and/or weakness
• Infection
• Renal failure
• Death [29][5]

Postoperative and Rehabilitation Care

• Physical therapy to regain function and strength and prevent contractures and stiffness.
• Wound care and monitoring for any ischemia, infection, gangrene.
• Antibiotics if infection if warranted 
• Pain medicine 
• The patient will need to learn how to use an ambulatory device like crutches until healing is complete.
• An occupational therapy consult is recommended to help teach the patient how to perform daily living activities. [32][33][34] 

Consultations

Management of acute compartment syndrome involves a multidisciplinary approach. Initially, the patient is attended to by a general or orthopedic surgeon. Depending on the complications, the following may be consulted in the management of patients with acute compartment syndrome:

• Infectious disease
• Wound care
• Physical therapy
• Occupational therapy

Deterrence and Patient Education

Patients should be educated to seek care after a traumatic injury or if they develop pain or swelling of an extremity. If a fasciotomy is performed, adequate wound care is of utmost importance.

Pearls and Other Issues

When applying plaster casts, especially following reduction, uni-valving or bi-valving can help to reduce the pressure by about 50%. Beware that once the initial swelling dissipates, the cast can become excessively loose, which can decrease the amount of reduction accomplished.

Enhancing Healthcare Team Outcomes

The management of acute compartment syndrome requires a well-integrated interprofessional team of healthcare professionals including nurses, laboratory technologists, pharmacists, and multiple physicians in different specialties. Without proper management, acute compartment syndrome can lead to high morbidity and poor outcomes. 

• The nurses are usually the first health professional to see the patient, often in triage in the emergency department. The nurse must quickly recognize the signs and symptoms consistent with compartment syndrome and immediately involve the clinical team to further evaluate the patient. The nurses will need to assist in monitoring the patient's vital signs, pain, and assist in getting the patient to the operating room where definitive treatment usually takes place. After the procedure, they will need ongoing evaluation as often a patient with compartment syndrome will have multiple other injuries that require attention as well as complications as a direct result of the compartment damage.
• Pharmacists in the emergency department can assist in medication reconciliation as well as provide recommendations regarding pain management.
• The nurse practitioner, physician assistant, and physicians often provide a role in coordinating the care, performing procedures, as well as educating the patient and family regarding the nature of the injuries.

After surgery, an interprofessional team that provides a holistic approach can help achieve the best possible outcomes for patients. This may include the surgery or orthopedics team, nurses, physical therapists, occupational therapists, pharmacists, and social workers. Due to the complexity of care required, the best outcomes will be achieved by the use of an interprofessional team.[35][36]