Mason is a 55-year-old homeless man who you are seeing today for the first time. He is a smoker and states that he has frequent colds and a routine morning cough. He used to be short of breath just walking up hills, but he now has difficulty breathing with everyday activities and is having trouble finding food because he cannot walk very far. He just wants medicine to help him survive on the streets. On examination, you find him using his accessory muscles to breathe. His vital signs are 99°, 100 beats per minute, 28 respirations/min., and blood pressure 140/90. Breath sounds are distant with end-expiratory wheezes. He has a slight barrel chest and neck vein distention.