A 28-year-old woman is brought to the emergency department 4 hours after a motor vehicle accident with a crush injury to her right forearm. She has severe pain, swelling, and pain with passive finger extension. Clinical examination reveals intact distal pulses and normal capillary refill. Compartment pressure in the deep flexor compartment is measured at 58 mmHg (diastolic BP 75 mmHg). What is the most appropriate immediate management?