Compartment syndrome develops when the pressure in the inelastic fascial space increases to a point where it causes compression and dysfunction of venous outflow. Major vascular and neural compromise lead to the classic five “Ps” of late compartment syndrome: pallor, paresthesias, poikilothermia, paralysis, and pulselessness. Compartment syndrome may result from exertion, circumferential burns, frostbite, constrictive dressings, arterial bleeding, severe soft tissue injury, and fractures. It can occur anywhere, but most commonly occurs in the anterior compartment of the leg and volar compartment of the forearm.
Compartments. The four compartments of the lower leg (A) and forearm compartments (B). (Reproduced with permission from Tintinalli JE, Stapczynski J, Ma O, Yealy DM, Meckler GD, Cline DM, eds. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide. 8th ed. New York, NY: McGraw Hill; 2016.)
The earliest symptom is severe pain out of proportion to the physical findings. The involved compartment is extremely firm. The pain is worsened with passive range of motion due to ischemic muscle fiber stretch. Consequently, the patient often holds the injured part in a position relaxing the involved muscle groups. Paresthesia is a late sign of nerve compromise, commonly with vibratory sensation lost first. Motor weakness, pallor, poikilothermia, and pulselessness are very late signs and only occur after irreversible muscle, nerve, and vascular damage. The goal is to identify compartment syndrome before these late signs occur; ischemic injury occurs around 4 hours and becomes irreversible around 8 hours.
The diagnosis is confirmed by measuring compartment pressures; greater than 30 mm Hg is suggestive and should prompt surgical consultation for fasciotomy consideration. A delta pressure (diastolic blood pressure – measured compartment pressure) less than 30 mm Hg should also prompt surgical evaluation. Measurements should be obtained within 5 cm of the site.
A serious complication is Volkmann ischemic contracture, classically following a supracondylar fracture. Postischemic swelling produces increased pressure within the enclosed osteofascial forearm compartment and reduces capillary blood perfusion below the level necessary for tissue viability. If not addressed, muscle and nerve necrosis eventually become replaced by fibrotic tissue and produces a contracture. Refusal to open the hand, pain with passive extension of the fingers, and forearm tenderness are signs of Volkmann ischemia.
Compartment Syndrome. Late anterior compartment syndrome of the left lower extremity is manifested by anterior tibial pain and tense “woody” swelling. (Photo contributor: Timothy Coakley, MD.)
Management and Disposition
Initial treatment is removal of constrictive dressings and jewelry as well as frequent reevaluation. If there is no improvement, decompression via a fasciotomy should ...