Review Question - QID 103325

A 65-year-old man presents to the emergency room complaining of severe pain in his right knee. He states that the pain has developed over the last few days and has gotten to the point where he cannot bear any weight on his right leg. He also describes fevers over the past 2 days. He has a history of hypertension for which he takes amlodipine. His surgical history is unremarkable. He does not smoke cigarettes, drinks alcohol socially, and denies illicit drug use. He works as a plumber. The patient's temperature is 102.0°F (38.9°C), blood pressure is 140/80 mmHg, pulse is 92/min, and respirations are 20/min. On exam, his right knee is severely swollen, erythematous, and warm to touch. Palpation of the patient's knee elicits 9/10 pain and he is unable to tolerate any range of motion. A radiographic series of the right knee shows no acute fractures. He undergoes aspiration of the right knee joint and a peripheral smear and Gram stain of the joint fluid from the knee is shown in Figure A. In addition to surgical debridement, which of the following is the most appropriate treatment for this patient?