Pulmonary Disease, Chronic ObstructiveForced Expiratory VolumeBronchodilator AgentsLung Diseases, ObstructiveDyspneaSpirometryPhosphodiesterase 4 InhibitorsRespiratory Function TestsVital CapacitySeverity of Illness IndexExercise ToleranceCyclopropanesOxygen Inhalation TherapyScopolamine DerivativesAminopyridinesAlbuterolAdministration, InhalationInspiratory CapacityMetered Dose InhalersGlycopyrrolateRespiratory MusclesIpratropiumTropanesPregnadienediolsAdrenergic beta-2 Receptor AgonistsEthanolaminesLung Volume MeasurementsCholinergic AntagonistsLungSmokingEmphysemaAdrenal Cortex HormonesExercise TestTreatment OutcomeMuscarinic AntagonistsQuality of LifeResidual VolumeSputumExercise TherapyTotal Lung CapacityPulmonary EmphysemaDiaphragmCross-Over StudiesBreathing ExercisesQuadriceps MuscleAndrostadienesOxygenDouble-Blind MethodNebulizers and VaporizersStatistics, NonparametricWalkingCarbon DioxideDrug CombinationsHypercapniaQuestionnairesCase-Control StudiesDrug Therapy, CombinationAdrenergic beta-AgonistsHospitalizationDisease ProgressionBenzamidesGlucocorticoidsCohort StudiesExerciseActivities of Daily LivingCross-Sectional StudiesRespirationProspective StudiesSingle-Blind MethodCost-Benefit AnalysisTime FactorsDrug Administration ScheduleHealth StatusRespiratory MechanicsPulmonary MedicineRandomized Controlled Trials as TopicRisk FactorsPrognosisRespiratory System AgentsFollow-Up StudiesBronchitis, ChronicAsthmaExhalationRespiratory TherapyExpectorantsBronchiRespiratory InsufficiencySmokealpha 1-Antitrypsin DeficiencyBronchitisIndansPrevalenceAirway ObstructionComorbidityAirway RemodelingBiological MarkersPneumoniaBreath TestsSmoking CessationRespiratory Mucosa