Compartment syndrome Health Article

Definition

Compartment syndrome is the compression of nerves and blood vessels within an enclosed space. This leads to muscle and nerve damage and problems with blood flow.

Causes, incidence, and risk factors

Thick layers of tissue called fascia separate groups of muscles in the arms and legs from each other. Inside each layer of fascia is a confined space, called a compartment, that includes the muscle tissue, nerves, and blood vessels. Fascia surrounds these structures much like insulation covers wires.

Fascia do not expand, so any swelling in a compartment will lead to increasing pressure in that area, which will push on the muscles, blood vessels, and nerves. If this pressure is high enough, blood flow to the compartment will be blocked, which can lead to permanent injury to the muscle and nerves. If the pressure lasts long enough, the limb may die and need to be amputated.

Swelling leading to compartment syndrome is associated with trauma such as from a car accident or crush injury, or surgery. Compartment syndrome may also occur if you wear a tight bandage or a cast that is too tight.

Long-term (chronic) compartment syndrome can be caused by repetitive activities, such as running, which increase the pressure in a compartment only during that activity.

Compartment syndrome is most common in the lower leg and forearm, although it can also occur in the hand, foot, thigh and upper arm.

Symptoms

The hallmark symptom of compartment syndrome is severe pain that does not go away when you take pain medicine or raise the affected area. In more advanced cases, symptoms may include:

• Decreased sensation
• Paleness of skin
• Weakness

Signs and tests

A physical exam will reveal:

• Severe pain when moving the affected area (for example, a person with compartment syndrome in the foot or lower leg will experience severe pain when moving the toes up and down)
• Tensely swollen and shiny skin
• Pain when the compartment is squeezed

Confirming the diagnosis involves directly measuring the pressure in the compartment. This is done using a needle attached to a pressure meter into the compartment. The needle is inserted into the affected area. Compartment syndrome is diagnosed if the pressure is greater than 45 mmHg or when the pressure is within 30 mmHg of the diastolic blood pressure (the lower number of the blood pressure).

When chronic compartment syndrome is suspected, this test must be performed immediately after the activity that causes pain.