A 25-year-old male patient arrives by air transport after being rescued from a building collapse. He has significant swelling and pain in his left leg, which is unresponsive to analgesics. You notice the leg is tense and there is decreased sensation. Which intervention is immediate and necessary to prevent irreversible damage?
Administering additional analgesics
Performing or preparing the patient for a fasciotomy
Elevating the affected limb to reduce swelling
Monitoring vital signs closely