Compartment Syndrome

Compartment syndrome occurs when pressure within a closed fascial compartment rises above capillary perfusion pressure (normal compartment pressure is 0–8 mmHg; syndrome develops when pressure exceeds 30 mmHg or is within 30 mmHg of diastolic blood pressure). Swelling from fractures, burns, tight casts, or crush injuries traps blood and fluid inside the compartment. As pressure climbs, capillary flow stops, and muscle and nerve ischemia begins. Irreversible damage starts within 4–6 hours. The hallmark assessment uses the 6 P's (pain, paresthesia, paralysis, pallor, pulselessness, poikilothermia), but pain is the earliest and most reliable sign — specifically, pain out of proportion to the injury that worsens with passive stretch of the affected muscles. Paresthesias follow. Pulselessness is a late, ominous finding meaning damage is already severe. Nursing priority: if you suspect compartment syndrome, immediately loosen or bivalve the cast, remove constrictive dressings, keep the limb at heart level (not elevated — elevation decreases arterial inflow to already ischemic tissue), and notify the surgeon stat. The definitive treatment is a fasciotomy, which the surgeon must perform urgently. Compartment pressure can be measured directly with a needle manometer, but clinical assessment should never wait for numbers.