soft tissue trauma that does not necessarily involve a fracture Poisonous snakebites, especially pit vipers, and deep tissue infections such as myositis or fasciitis may also lead to dangerous elevations of compartment pressures Clinical Assessment/Initial H&P The “five Ps” of compartment syndrome is a mnemonic that should be replaced by the “three As.” Pain alone is often the only early symptom or sign of vascular insufficiency when interventions should be started Anxiety, Agitation, and Analgesia requirement, which are manifestations of pain in children, should provoke consideration of compartment syndrome The astute clinician should suspect compartment syndrome and consult an orthopedic surgeon before paresthesia, pallor, paralysis, and pulselessness are present Pain, the hallmark of compartment syndromes, is a symptom in almost all significant injuries Distinguishing the pain from the injury itself from that related to the vascular insufficiency is difficult Pain that increases over time or seems out of proportion to the injury itself suggests muscle ischemia Full extension of the fingers or toes stretches ischemic muscles and exacerbates the pain in compartment syndromes, making this part of the examination especially important in patients at risk for compartment syndromes Paresthesia may be noted in the distribution of the nerves that traverse the ischemic compartment When the flexor compartment of the forearm is involved, the median nerve is usually affected Over time, paresthesias may progress to complete anesthesia, and pain may decrease Pallor from decreased perfusion may be noted distally Sluggish circulation may cause cyanosis Paralysis is a late finding and is probably the least sensitive marker for compartment syndrome Pulselessness is a useful finding if present, but some physicians are falsely reassured when distal pulses are palpable Collateral circulation can preserve pulses in larger vessels but the ischemia in compartment syndromes results from vascular occlusion of small vessels Management/Diagnostic Testing Treatment of a compartment syndrome should begin from the moment it is suspected All circumferential bandages should be removed If symptoms persist, measurement of compartment pressures should be obtained, by the emergency clinician or in consultation with an orthopedic surgeon Reduction of displaced fractures can improve blood flow to affected compartments Fasciotomy in the operating room is indicated if compartment pressures remain high