Osteomyelitis Quiz: Ace Your Exams

A 60-year-old man presents to the emergency department due to progressive pain, redness, and swelling of the left foot for the past week, and 2 days of fevers and chills. Four weeks ago, the patient was diagnosed with a diabetic foot ulcer on the plantar surface at the base of the first left toe. Past medical history is significant for poorly controlled diabetes mellitus. Temperature is 38.8°C (101.9°F), heart rate is 110/min, blood pressure is 93/68 mm Hg, respiratory rate is 22/min, and oxygen saturation is 94% on room air. Physical examination reveals an erythematous, swollen left foot with an open 2 ½ cm ulcer on the plantar surface at the base of the left toe. The foot is warm to the touch, and there is tenderness to palpation at the site of the ulcer and purulent discharge is present. Bone is felt when probing the ulcer with a sterile surgical probe. Laboratory evaluation is significant for a white blood cell (WBC) count of 18,000/μL (4,500-11,000/μL), C-reactive protein (CRP) of 120 mg/L (<5 mg/L), and an elevated lactate dehydrogenase (LDH) level of 350 U/L (60-160 U/L). Intravenous fluids are initiated and blood and wound cultures are sent. Which of the following is the best next step in management?