system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
An 18-year-old man is hospitalized after a suicide attempt, his 6th such attempt in the last 4 years. He was diagnosed with depression 5 years ago, for which he takes fluoxetine. He is currently complaining of severe and worsening left knee swelling and pain since he attempted suicide by jumping out of his second-story bedroom window. He sustained minor injuries at the time, primarily lacerations to his arms and knees, and he was admitted to the hospital’s psychiatric unit. His blood pressure is 110/72 mm Hg, heart rate is 88/min, and temperature is 38°C (100.4°F). On examination, the knee is erythematous and edematous, and it feels warm to the touch. The patient’s lab studies reveal a hemoglobin level of 11.9 g/dL, leukocyte count of 11,200/µL, and a platelet count of 301,000/µL. Arthrocentesis yields 15 mL of fluid with a leukocyte count of 61,000/µL, 93% neutrophils, and an absence of crystals under polarized light microscopy. A gram stain of joint fluid is negative; however, mucosal, blood and synovial fluid cultures are still pending. Which of the following is the most appropriate next step in the management of this patient?
assistant
Administer intravenous antibiotics and repeat arthrocentesis