A 70-year-old male presents with a 6-month history of dyspne…

A 70-year-old male presents with a 6-month history of dyspnea on exertion and chronic cough. He admits to a 30-pack year history of cigarette smoking. Examination reveals increased AP diameter and decreased bilateral breath sounds with prolonged expiration. Oxygen saturation is 94% on room air. Which of the following interventions in addition to smoking cessation is appropriate at this time?