A 32-year-old male presents to the emergency department 6 hours after a motor vehicle collision with a closed fracture of the right femur. On examination, the limb is swollen and tense. The skin over the fracture site is intact but shows early signs of blistering. Compartment pressures measured in the anterior compartment are 65 mmHg (diastolic BP 80 mmHg). What is the most appropriate next step in management?