DyspneaOxygenOxygen ConsumptionReactive Oxygen SpeciesOxygen Inhalation TherapySinglet OxygenOxygen IsotopesPulmonary Disease, Chronic ObstructiveExercise ToleranceRespiratory Function TestsPartial PressureHyperbaric OxygenationAnoxiaOximetryForced Expiratory VolumeExercise TestDyspnea, ParoxysmalHydrogen PeroxideOxidation-ReductionOxidative StressLung Diseases, ObstructiveSpirometryBlood Gas AnalysisCarbon DioxideLungVital CapacityRespirationTime FactorsAntioxidantsSeverity of Illness IndexOxyhemoglobinsRespiratory MusclesPulmonary Gas ExchangeAerobiosisSuperoxide DismutaseHemoglobinsFree RadicalsAirway ObstructionFree Radical ScavengersMitochondriaCatalaseHyperoxiaNADPH OxidaseCell HypoxiaCoughAnaerobiosisTreatment OutcomeInspiratory CapacitySuperoxidesLung DiseasesBreathing ExercisesQuality of LifePhysical ExertionExerciseRadiography, ThoracicRespiratory MechanicsHeart FailureBronchodilator AgentsHemodynamicsLung Volume MeasurementsPulmonary VentilationPolarographyScopolamine DerivativesRespiratory InsufficiencyAcute DiseaseInhalationProspective StudiesLung Diseases, InterstitialLuminescent MeasurementsFatal OutcomeKineticsHeliumWork of BreathingHeart RateEnergy MetabolismAdministration, InhalationBlood SubstitutesTomography, X-Ray ComputedWalkingBlood Gas Monitoring, TranscutaneousOxidantsMaximal Voluntary VentilationBronchial DiseasesCells, CulturedPulmonary Diffusing CapacityPhysical EnduranceAsthmaOxygen RadioisotopesXanthine OxidaseNitric OxideReactive Nitrogen SpeciesAcetylcysteineHypertension, PulmonaryDouble-Blind MethodGlutathioneHemoptysisBronchoscopyPulmonary EmphysemaDose-Response Relationship, DrugTotal Lung Capacity