Compartment syndrome

Acute

There are five signs and symptoms of acute compartment syndrome.^[6] They are known as the "5 Ps": pain, pallor, decreased pulse, paresthesia, and paralysis.^[6] Pain and paresthesia are the early symptoms of compartment syndrome.^[17][6]

Common symptoms are:

• Pain: A person may feel pain greater than the exam findings.^[6] This pain may not be relieved by strong painkillers, including opioids like morphine.^[18] It may be due to nerve damage from ischemia.^[6] A person may experience pain disproportionate to the findings of the physical examination.^[19] The pain is aggravated by passively stretching the muscle group within the compartment.^[19] However, such pain may disappear in the late stages of the compartment syndrome.^[17]
• Paresthesia (altered sensation): A person may complain of "pins and needles," numbness, and a tingling sensation. This may progress to loss of sensation (anesthesia) if no intervention is made.^[17]

Uncommon symptoms are:

• Paralysis: Paralysis of the limb is a rare, late finding.^[5] It may indicate both a nerve or muscular lesion.^[17]
• Pallor: Pallor describes the loss of color to the affected limb.^[8] Other skin changes can include swelling, stiffness, or cold temperature.^[9]
• Pulselessness: A lack of pulse rarely occurs in patients, as pressures that cause compartment syndrome are often lower than arterial pressures.^[5] Absent pulses occur only with arterial injury or late-stage compartment syndrome, when pressures are very high.^[5]

Chronic

Chronic exertional compartment syndrome, CECS, may cause pain, tightness, cramps, weakness, and numbness.^[20] This pain can last for months or even years, but rest may relieve it.^[21] There may also be mild weakness in the affected area.^[11]

Exercise causes these symptoms.^[22] They start with muscle tightness, then a painful burning if exercise continues.^[22] After exercise stops, the compartment pressure will drop in a few minutes.^[16] This will relieve the pain.^[21] Symptoms will occur after a certain level of exercise.^[11] This threshold can range anywhere from 30 seconds of running to 2–3 miles of running.^[23] CECS most often occurs in the lower leg.^[11] The anterior compartment is most affected.^[11] Foot drop is a common symptom.^[21][22]

Acute

Acute compartment syndrome (ACS) is a medical emergency.^[5] It can develop after traumatic injuries, like car accidents, gunshot wounds, fractures, or intense sports.^[24] Examples include a severe crush injury or an open or closed fracture of an extremity.^[24] Rarely, ACS can develop after a minor injury or another medical issue.^[25] It can also affect the thigh, buttock, hand, abdomen, and foot.^[17][12] The most common cause of acute compartment syndrome is a fractured bone, usually the tibia.^[12][26] Leg compartment syndrome occurs in 1% to 10% of tibial fractures.^[6] It is strongly linked to tibial diaphysis fractures and other tibial injuries.^[27] Direct injury to blood vessels can reduce blood flow to soft tissues, causing compartment syndrome.^[24] Compartment syndrome can also be caused by:

• intravenous drug injection
• casts
• prolonged limb compression
• crush injuries
• anabolic steroid use
• vigorous exercise
• eschar from burns^[28][29]

Patients on anticoagulant therapy, or those with blood disorders such as hemophilia or leukemia are at higher risk of developing compartment syndrome.^[30][31][17]

Abdominal compartment syndrome occurs when the intra-abdominal pressure exceeds 20 mmHg and abdominal perfusion pressure is less than 60 mmHg.^[32] There are many causes, which can be broadly grouped into three mechanisms: primary (internal bleeding and swelling); secondary (vigorous fluid replacement as an unintended complication of resuscitative medical treatment, leading to the acute formation of ascites and a rise in intra-abdominal pressure); and recurrent (compartment syndrome that has returned after the initial treatment of secondary compartment syndrome).^[32][33]

Compartment syndrome after snake bite is rare.^[34] Its incidence varies from 0.2 to 1.36% as recorded in case reports.^[35] Compartment syndrome after a snake bite is more common in children.^[34] Increased white blood cell count of more than 1,650/μL and aspartate transaminase (AST) level of more than 33.5 U/L are associated with developing compartment syndrome.^[35] Otherwise, those bitten by venomous snakes should be observed for 48 hours to exclude the possibility of compartment syndrome.^[35]

Acute compartment syndrome due to severe/uncontrolled hypothyroidism is rare.^[36]

Chronic

When repeated use of the muscles causes compartment syndrome, it is chronic compartment syndrome (CCS).^[37][38] This is usually not an emergency, but loss of circulation can damage nearby nerves and muscles.^[38] The damage may be temporary or permanent.^[37][38]

A subset of chronic compartment syndrome is chronic exertional compartment syndrome (CECS), often called exercise-induced compartment syndrome (EICS).^[39] CECS is often a diagnosis of exclusion.^[40] CECS of the leg is caused by exercise.^[41] This condition occurs commonly in the lower leg and various other locations within the body, such as the foot or forearm.^[11] CECS can be seen in athletes who train rigorously in activities that involve constant repetitive actions or motions.^[39]

Acute

If external compression, such as a cast or tourniquet, has caused increased pressure, it is removed and the limb placed at heart level. Otherwise, fasciotomy, a cut into the fascia beneath the skin, immediately decreases pressure and is generally the only effective treatment.^[17] Although closing a fasciotomy wound quickly reduces complications, this is not typically achievable as compartment syndrome may recur. Before the wound is closed, it may be covered with moist dressings or, in some cases, treated with negative-pressure wound therapy, which can additionally be used for closure. Closure is often achieved using the so-called shoelace technique, where staples are inserted into the skin which are used to pull the sides of the wound together with a thread. A skin graft may be needed to close the wound.^[49] Fasciotomy is often not necessary when compartment syndrome is caused by snake bites, where pressure may instead be relieved with antivenom.^[50]

Chronic

Chronic exertional compartment syndrome can be treated by reducing or stopping exercise and other activities; massage; non-steroidal anti-inflammatory medication; and physiotherapy^[1] If symptoms persist after basic treatment, compartment syndrome may be treated with a fasciotomy.^[51][47]

Complications

If pressure is not relieved, tissues may die (necrosis) in the affected compartment.^[9][25] Blood will be unable to enter the smallest vessels.^[5][44] Capillary perfusion pressure will fall.^[5][44] This, in turn, leads to a gradual lack of oxygen in the tissues that depend on this blood supply.^[55] Without enough oxygen, the tissue will die.^[54] On a large scale, this can cause Volkmann's contracture in the affected limbs.^[56][57][58] It is permanent and irreversible.^[56] Other complications include neurological deficits, gangrene, and chronic regional pain syndrome.^[59] Rhabdomyolysis and kidney failure are also possible.^[60] Some case series report rhabdomyolysis in 23% of patients with ACS.^[17]