A client with a closed fracture has just had a cast applied and reports intense pain unrelieved by elevation, ice, and analgesia. Which condition best explains the pain?

A client with a closed fracture has just had a cast applied and reports intense pain unrelieved by elevation, ice, and analgesia. Which condition best explains the pain?

• A. Nerve entrapment
• B. Acute compartment syndrome
• C. Cast allergy
• D. Impaired tissue perfusion

Answer: (B)

Acute compartment syndrome is the most likely explanation. After a fracture, swelling within a closed muscular compartment increases pressure inside the fascia. When a cast is applied, it can further restrict expansion, trapping the swelling. The resulting rise in intracompartmental pressure compromises blood flow, causing ischemia and a severe, disproportionately intense pain that often remains despite elevation, ice, and analgesia. Pain may worsen with passive movement of the affected muscles, and the limb can become tense and swollen if the condition progresses. This is a true emergency because delaying relief of the pressure can lead to muscle necrosis and nerve damage, sometimes requiring cast removal or fasciotomy to restore perfusion. Nerve entrapment would typically produce pain and sensory changes along a specific nerve distribution rather than the urgent, whole-compartment picture. A cast allergy would present with itching or dermatitis rather than severe, unrelieved pain and tense swelling. Impaired tissue perfusion is related but nonspecific; the hallmark in this scenario is the acute, pressure-driven compartment syndrome causing rapidly evolving ischemia.

Acute compartment syndrome is the most likely explanation. After a fracture, swelling within a closed muscular compartment increases pressure inside the fascia. When a cast is applied, it can further restrict expansion, trapping the swelling. The resulting rise in intracompartmental pressure compromises blood flow, causing ischemia and a severe, disproportionately intense pain that often remains despite elevation, ice, and analgesia. Pain may worsen with passive movement of the affected muscles, and the limb can become tense and swollen if the condition progresses. This is a true emergency because delaying relief of the pressure can lead to muscle necrosis and nerve damage, sometimes requiring cast removal or fasciotomy to restore perfusion.

Nerve entrapment would typically produce pain and sensory changes along a specific nerve distribution rather than the urgent, whole-compartment picture. A cast allergy would present with itching or dermatitis rather than severe, unrelieved pain and tense swelling. Impaired tissue perfusion is related but nonspecific; the hallmark in this scenario is the acute, pressure-driven compartment syndrome causing rapidly evolving ischemia.