Review Question - QID 213229

A 65-year-old man presents to the emergency department with confusion and chest pain. He states his symptoms started after he landed on a return flight from Brazil. Since then, the patient states that he feels anxious, short of breath, and has pleuritic chest pain. The patient has a past medical history of diabetes and chronic kidney disease. His medications include insulin, lisinopril, aspirin, and atorvastatin. His temperature is 101°F (38.3°C), blood pressure is 154/94 mmHg, pulse is 90/min, respirations are 17/min, and oxygen saturation is 96% on room air. Physical exam is notable for a confused man. The patient’s laboratory studies are ordered as seen below.

Serum:
Na+: 140 mEq/L
Cl-: 103 mEq/L
K+: 5.3 mEq/L
HCO3-: 25 mEq/L
BUN: 33 mg/dL
Glucose: 168 mg/dL
Creatinine: 1.8 mg/dL
Ca2+: 10.0 mg/dL
Troponin: < 0.05 mcg/L

A chest CT angiogram, an echocardiogram (ECG), and a second troponin are ordered and are all unremarkable. The patient’s chest pain resolves with diazepam. A lumbar puncture is performed and based on the results the patient is subsequently started on acyclovir. Which of the following is the best next step in management?