Compartment syndrome is a well-described complication of traumatic injury; for the purposes of this CPG, only extremity compartment syndrome will be discussed. Definitive treatment is complete surgical release of the extremity compartments affected. The APMS consultant and trauma surgeon should have a detailed discussion regarding patients who are at high risk for compartment syndrome. Pain control may mask the typical early sign of compartment syndrome: increased pain in the compartment. Any patient at risk for extremity compartment syndrome who is awake and has an increased pain medication requirement should be promptly and thoroughly assessed for increased compartment pressure. For patients with regional or neuraxial analgesia affecting an extremity that is felt to be at risk for compartment syndrome, more frequent clinical assessments and monitoring of the extremity are warranted. If the patient is unable to reliably detect and report pain and there are any clinical or examination findings concerning for a compartment syndrome, then bedside assessment of compartment pressures or performance of a fasciotomy should be done promptly. If there is any concern for compartment syndrome, then full compartment release with fasciotomies must be completed prior to aeromedical transportation. Newer monitoring technologies such as near infrared spectroscopy; have shown some promise in early noninvasive detection of compartment syndrome; however, they are not currently the standard of care.