Emergency and Toxicologymiddle twist
A 24-year-old man sustains a closed fracture of the midshaft of the left tibia playing football. A plaster backslab with encircling crepe bandage is applied and he is admitted for elevation while awaiting internal fixation. Eight hours later he reports steadily worsening pain in the leg despite repeated doses of intravenous morphine, and says the top of his foot feels numb. When nursing staff passively straighten his toes he cries out with severe calf pain. The foot is warm and the dorsalis pedis pulse is palpable. Which one of the following is the most appropriate immediate next step in management?