Review Question - QID 210597

A 67-year-old man presents to the emergency department with shortness of breath. He states that he was at home when his symptoms began. Further history is not obtained as the patient is having trouble speaking. His temperature is 99.5°F (37.5°C), blood pressure is 167/118 mmHg, pulse is 120/min, respirations are 25/min, and oxygen saturation is 78% on room air. A chest radiograph is obtained as seen in Figure A. The patient is started on oxygen, albuterol, and ipratropium. Repeat vitals demonstrate an oxygen saturation of 88% on 4 liters O2 via nasal cannula. The patient states his symptoms started while he was working in his garage. Which of the following is the most appropriate next step in management?