* This is the Professional Version. *
Compartment syndrome is increased tissue pressure within a closed fascial space, resulting in tissue ischemia. The earliest symptom is pain out of proportion to the severity of injury. Diagnosis is usually by measuring compartment pressure. Treatment is fasciotomy.
Compartment syndrome is a self-perpetuating cascade of events. It begins with the tissue edema that normally occurs after injury (eg, because of soft-tissue swelling or a hematoma). If edema develops within a closed fascial compartment, typically in the anterior or posterior compartments of the leg, there is little room for tissue expansion, so interstitial (compartment pressure) increases. As compartmental pressure exceeds the normal capillary pressure of about 8 mm Hg, cellular perfusion slows and may ultimately stop. (NOTE: Because 8 mm Hg is much lower than arterial pressure, cellular perfusion can stop long before pulses disappear.) Resultant tissue ischemia further worsens edema in a vicious circle.
As ischemia progresses, muscles necrose, sometimes leading to rhabdomyolysis, infections, and hyperkalemia; these complications can cause loss of limb and, if untreated, death. Hypotension or arterial insufficiency can compromise tissue perfusion with even mildly elevated compartment pressures, causing or worsening compartment syndrome. Contractures may develop after necrotic tissue heals.
Compartment syndrome is mainly a disorder of the extremities and is most common in the lower leg and the forearm. However, compartment syndrome can also occur in other locations (eg, upper arm, abdomen, buttock).
* This is a professional Version *