A nurse is assisting with the care for a client who has a new cast on their left forearm and reports severe pain in the affected arm with numbness in the fingers. The nurse finds the skin is pale and cold with sluggish capillary refill. Which of the following fracture complications should the nurse suspect?

The classic signs of compartment syndrome are the six P's: pain (especially pain out of proportion to the injury or with passive stretch), pallor, paresthesia (numbness), paralysis, pulselessness, and poikilothermia (cold skin). This client presents with severe pain, numbness in the fingers, pale and cold skin, and sluggish capillary refill — hallmark findings of compartment syndrome, a surgical emergency caused by increased pressure within a closed muscle compartment that compromises blood flow and tissue perfusion. A new cast can act as a constrictive device, preventing the swelling tissues from expanding and rapidly increasing compartmental pressure. Fat embolism typically presents with respiratory distress, petechiae, and altered mental status — not localized limb ischemia with a cold, pale extremity. Deep vein thrombosis presents with warmth, redness, and swelling rather than pallor and cold skin. Osteomyelitis is a bone infection manifesting with fever, localized bone pain, and warmth, which develops over days to weeks rather than acutely after casting. The combination of ischemic signs in the fingers, pale and cold skin, and sluggish capillary refill following new cast application most strongly points to compartment syndrome, requiring immediate provider notification and potentially emergency fasciotomy.