Acute compartment syndrome (ACS) is a limb-threatening and potentially life-threatening surgical emergency that occurs when pressure within a closed osseofascial compartment rises to a level that compromises the perfusion and viability of the tissues within that compartment. The pathophysiology involves a cascade of events that, if not interrupted by timely fasciotomy, leads to irreversible muscle necrosis (within 6-8 hours), nerve damage, rhabdomyolysis, renal failure, and potential limb loss or death. The registered nurse plays a pivotal role in early detection through serial neurovascular assessments, as compartment syndrome can progress from reversible ischemia to irreversible necrosis within hours. The osseofascial compartment is an anatomical space bounded by bone and dense, inelastic fascia. The fascia's inability to expand is the fundamental problem in compartment syndrome -- it converts any increase in compartment volume or any decrease in compartment size into increased intracompartmental pressure (ICP). The lower leg has four compartments (anterior, lateral, superficial posterior, and deep posterior), the forearm has three compartments (volar/flexor, dorsal/extensor, and mobile wad), and the thigh has three compartments (anterior, posterior, and medial). The anterior compartment of the...