Compartment syndrome is increased pressure in the space around certain muscles. It occurs when injured muscles swell so much that they cut off their blood supply.
- Pain in the injured limb increases and is more severe than expected, and as the syndrome worsens, the limb may become numb, swollen, pale, and cool to the touch.
- Doctors suspect the diagnosis based on symptoms and confirm it by checking the pulse in the limb and measuring pressure in the compartment.
- Doctors immediately remove anything confining the limb, such as a splint or a cast, and if this measure is ineffective, emergency surgery is done to relieve the pressure.
- If tissues in the limb die because their blood supply is cut off, the limb may have to be amputated.
Compartment syndrome is rare but serious. It may result in loss of a limb. Or muscles in the affected limb may become permanently shortened (called a contracture).
Certain muscles, such as those of the lower leg, are surrounded by a tight covering made of fibrous tissue called fascia. This covering forms a closed space (compartment) that contains muscle tissue, blood vessels, and nerves. This space cannot expand to accommodate the swelling that occurs when muscles or bones inside the compartment are severely damaged. Because there is not enough room for the swelling, pressure on the muscle tissue in the compartment increases. The increased pressure puts pressure on the blood vessels in the area, and blood cannot reach the muscle tissue and provide it with oxygen. If the muscle is deprived of oxygen for too long, the muscle is damaged further, causing more swelling and increasing pressure in the tissues. After only a few hours, muscle and nearby soft tissue are irreversibly damaged and start to die.
Compartment syndrome is more likely to occur after
- A fracture, particularly of the lower leg
- A crush injury to a limb
Rarely, compartment syndrome develops when a cast or bandage is too tight and cuts off the blood supply. Other rare causes include snakebites, severe exertion, or overdose of a drug (such as heroin or cocaine).
The first symptom of compartment syndrome may be increasing pain. The pain is typically worse than expected for the injury. Moving the fingers or toes in ways that stretch the affected muscles is painful. Pain relievers have little effect.
As the disorder worsens, people have abnormal sensations in the injured limb and may be unable to move the foot or hand of the injured limb. The limb may feel numb and be obviously swollen, and the skin may look pale and feel cool and tight. The risk of infections is increased.
- A doctor's evaluation
- Measuring pressure in the compartment
If people who have had an injury have the following symptoms, particularly if the injury was severe or if they have a splint or cast, they should see a doctor immediately:
- Increasing pain in an immobilized limb
- Pain when they gently move the fingers or toes of an immobilized limb
- Numbness in a limb
Doctors suspect compartment syndrome based on symptoms. To confirm the diagnosis, they check the pulse in the limb and measure pressure in the compartment. To measure the pressure, they may use a needle with a pressure monitor attached to it. They insert the needle into the compartment of the affected limb, just under the fascia. The monitor records the pressure, and the needle is removed. Or instead of a needle, they may insert a thin flexible tube (catheter) that remains in place so that pressure can be monitored continuously.
- Removal of anything confining the limb
- If needed, surgery to open the compartment
- If tissues in the limb have died, possibly amputation
Treatment must be begun before the limb becomes pale and before the pulse stops. If there is no pulse, tissues in the limb may be dead.
When doctors suspect this syndrome, they immediately remove anything that is confining the limb, such as a splint or a cast. If this measure does not relieve the pressure enough, an emergency surgical procedure called fasciotomy must be done to open the compartment. For this procedure, doctors make an incision along the entire length of the fascia that forms the compartment enclosing the swollen muscle. This incision relieves pressure and allows blood to reach the muscles. Doctors also remove any dead muscle tissue in the area.
If tissues in the limb have died because their blood supply was cut off, the limb may have to be amputated.
Without treatment, compartment syndrome can cause infections that can be fatal.