Review Question - QID 216576

A 67-year-old man presents to the emergency room with a 2 day history of progressively worsening fatigue and shortness of breath. His past medical history is significant for previous myocardial infarction, a 30-pack-year smoking history, gastroesophageal reflux disease, and poorly controlled hypertension. The patient’s only home medication is omeprazole. His temperature is 98.6°F (37°C), blood pressure is 140/90 mmHg, pulse is 90/min, respirations are 30/min, and oxygen saturation is 88% on room air. Physical exam is significant for a jugular venous pressure of 15 cm, an S3 heart sound, bibasilar crackles, and 2+ pitting edema to the knees bilaterally. His abdomen is soft and non-tender. His neurological exam is nonfocal and he walks with a steady gait. An arterial blood gas shows the following:

pH: 7.56 (normal 7.35-7.45)
pCO2: 25 mmHg (normal 35-45 mmHg)
HCO3: 29 mEq/L (normal 22-26 mEq/L)
pO2: 62 mmHg (normal 80-100 mmHg)
SaO2: 87% (normal 95-100%)

Which of the following is the most appropriate treatment?