Pulmonary Disease, Chronic ObstructiveSeverity of Illness IndexForced Expiratory VolumeSpirometryBronchodilator AgentsLung Diseases, ObstructiveDyspneaRespiratory Function TestsVital CapacityScopolamine DerivativesSmokingExercise TolerancePulmonary EmphysemaLungAdministration, InhalationCholinergic AntagonistsPulmonary MedicineSputumRespiratory System AgentsAdrenergic beta-2 Receptor AgonistsBronchitis, ChronicOxygen Inhalation TherapyAlbuterolAdrenal Cortex HormonesInspiratory CapacityEmphysemaQuality of LifeAsthma