Snapshot A 21-year-old man presents for evaluation of a painful right leg. He had previously had a tibial fracture and had a tightly bound cast in place. He reports excruciating pain when the cast is released and when the muscles underneath are palpated. A catheter is introduced into the limb and the intracompartmental pressures is 40 mmHg. A surgical consult is immediately called. Introduction Clinical definition a painful emergency condition that occurs when the tissue pressure inside an anatomical compartment, bound by fascia, exceeds the perfusion pressure, resulting in ischemia and necrosis Epidemiology location lower extremity > upper extremity leg forearm hand foot thigh risk factors trauma anticoagulation therapy bleeding disorders Etiology most common cause is a fracture tibia fracture soft tissue injury circumferential burns crush injuries constrictive dressing (e.g., splints, casts, or poor surgical positioning) penetrating wounds Pathogenesis blood flow is blocked when the tissue pressure exceeds the perfusion pressure within a fixed-volume compartment this results in a lack of oxygen and the accumulation of waste products, causing pain and decreased peripheral sensation irreversible tissue damage occurs between 6-8 hours after onset Prognosis higher chance of regaining function of the affected limb if a fasciotomy is performed within 12 hours Presentation Symptoms burning pain out of proportion to injury the most specific and important symptom pain with active contraction of the compartment may have paresthesia or numbness Physical exam firm, swollen, and wooden feeling of the muscles on palpation may have skin findings such as bullae ↓ vibration sensation ↓ 2-point discrimination 6 P’s are classifically associated with compartment syndrome Pallor Pain out of proportion worse with passive stretch Paresthesia “pins and needles” sensation Pulselessness Poikilothermia Paralysis late finding Imaging Radiography indication typically not needed for diagnosing compartment syndrome, but useful for characterizing any trauma such as fractures Studies Compartment pressure measurement indication to confirm diagnosis if clinicians are unable to elicit the symptoms or history modality a transducer is connected to a catheter and is used to measure the intracompartmental pressure (ICP) Making the diagnosis most cases are clinically diagnosed or guided by pressure measurement absolute ICP > 30 mm Hg Δ pressure (diastolic blood pressure - ICP) < 30 mmHg normal ICP = 0 mm Hg Differential Cellulitis distinguishing factor normal neurovascular exam Rhabdomyolysis distinguishing factors abnormal laboratory evaluation, including creatine phosphokinase, renal function studies, urine myoglobin, and potassium Treatment Management approach management is focused on early decompression observation and conservative management is appropriate only if ICPs are not high Conservative place limb at the level of the heart without elevation indication for all patients while awaiting the diagnosis or decompression immediate removal of any wraps, splints, or casts indication for all patients immobilization indication for all patients Operative fasciotomy indications ICP > 30 mmHg (with lower threshold for compartment syndrome of the hand) prolonged duration of compartment syndrome > 8 hours Complications Volkmann contracture permanent nerve and muscle damage