A client with a cast on the right forearm reports intense, deep-seated pain unrelieved by opioid analgesics and describes a 'pins and needles' sensation in the fingers. Which complication does the nurse suspect?

✓ Correct Answer: Option C

Unrelieved pain (especially with passive stretching), paresthesia ('pins and needles'), pallor, pulselessness, and paralysis are classic signs of compartment syndrome, a medical emergency requiring immediate intervention to prevent permanent tissue damage.