Review Question - QID 204295

An 80-year-old man presents to the emergency room complaining of weakness. Yesterday, he underwent an incision and drainage of an abscess in his back at his primary care physician's office. His past medical history is significant for hypertension, diabetes mellitus, and hypothyroidism. His medications include hydrochlorothiazide, metformin, and levothyroxine. His temperature is 38.6 C (101.5 F), blood pressure is 85/42 mm Hg, heart rate is 110/min, and respiratory rate is 16/min. Physical exam reveals moist mucous membranes and warm and well-perfused extremities. There are no abnormalities on cardiac, pulmonary, and abdominal exams. His back wound is edematous, warm, and erythematous under its gauze dressing. He becomes lightheaded upon sitting up. Initial laboratory results are as follows:
...