A 64-yeаr-оld mаn wаnts tо quit smоking. He has a barrel chest, wheezes on expiration, complains of increasing shortness of breath with exertion and has had to take several courses of antibiotics over the past two years for a productive cough that 'never goes away.' He sits hunched over in his chair in the doctor's office and obviously uses his chest and neck muscles during respiration. This man is suffering from: