An old man comes to see you because of shortness of breath

A 58yearold man comes to see you because of shortness of breath. He has experienced
evaluation. On physical examination, his blood pressure is 135/85 mm Hg, heart rate
has smoked about two packs of cigarettes per day since the age of 15 years. He does not drink
96 bpm, respiratory rate 28 breaths per minute, and temperature 36.4°C. He is sitting in
➤What is the most likely diagnosis? (Justify)
➤What is the next best diagnostic test? (Explain)

throughout the year. He denies chest pain, fever, chills, or lower extremity edema. He
alcohol. A few months ago, the patient went to an urgent care clinic for evaluation of
and chest examination reveals wheezes and rhonchi bilaterally, but no crackles are
➤What is the best initial treatment?