DefinitionofAsthma.docx
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DefinitionofAsthma
Definition-of-Asthma
GINAlobalitiativeforSthma2019.DefinitionofAsthmaAsthmaisachronicinflammatorydisorderoftheairwaysinwhichmanycellsandcellularelementsplayaroleChronicinflammationcausesanassociatedincreaseinairwayhyperresponsivenessthatleadstorecurrentepisodesofwheezing,breathlessness,chesttightness,andcoughing,particularlyatnightorintheearlymorningTheseepisodesareusuallyassociatedwithwidespreadbutvariableairflowobstructionthatisoftenreversibleeitherspontaneouslyorwithtreatmentMechanismsUnderlyingtheDefinitionofAsthmaRiskFactors(fordevelopmentofasthma)INFLAMMATIONAirwayHyperresponsivenessAirflowObstructionRiskFactors(forexacerbations)SymptomsBurdenofAsthmaAsthmaisoneofthemostcommonchronicdiseasesworldwidePrevalenceincreasinginmanycountries,especiallyinchildrenAmajorcauseofschool/workabsenceAnoverallincreaseinseverityofasthmaincreasesthepoolofpatientsatriskfordeathBurdenofAsthmaHealthcareexpendituresveryhighDevelopedeconomiesmightexpecttospend1-2percentoftotalhealthcareexpendituresonasthma.DevelopingeconomieslikelytofaceincreaseddemandPoorlycontrolledasthmaisexpensive;investmentinpreventionmedicationlikelytoyieldcostsavingsinemergencycareWorldwideVariationinPrevalenceofAsthmaSymptomsInternationalStudyofAsthmaandAllergiesinChildren(ISAAC)Lancet1998;351:
1225IncreasingPrevalenceofAsthmainChildren/Adolescents051015202530351992198219891975199219821994198919921982199219821991197919891966Finland(Haahtelaetal)Sweden(Abergetal)Japan(Nakagomietal)Scotland(Ronaetal)UK(Omranetal)USA(NHIS)NewZealand(Shawetal)Australia(Peatetal){Prevalence(%){{{{{{{Theprevalence,hospitalizationratesandmortalityinUSA.70605040302085868788899091929394Rate/1,000PersonsYear1818-4445-6465+Total(AllAges)Age(years)TrendsinPrevalenceofAsthmaByAge,U.S.,1985-1996959680HospitalizationRatesforAsthmabyAge,U.S.,1974-19974035302520157476788082848688Rate/100,000Persons10509092941515-4445-6465+96Year4311980Rate/100,000PersonsYear201985199019952019BlackMaleWhiteFemaleWhiteMaleBlackFemaleDeathRatesforAsthmaByRace,Sex,U.S.,1980-19985RiskFactorsforAsthmaHostfactors:
predisposeindividualsto,orprotectthemfrom,developingasthmaEnvironmentalfactors:
influencesusceptibilitytodevelopmentofasthmainpredisposedindividuals,precipitateasthmaexacerbations,and/orcausesymptomstopersistFactorsthatExacerbateAsthmaAllergensAirPollutantsRespiratoryinfectionsExerciseandhyperventilationWeatherchangesSulfurdioxideFood,additives,drugsRiskFactorsthatLeadtoAsthmaDevelopmentHostFactorsGeneticpredispositionAtopyAirwayhyper-responsivenessGenderRace/EthnicityEnvironmentalFactorsIndoorallergensOutdoorallergensOccupationalsensitizersTobaccosmokeAirPollutionRespiratoryInfectionsParasiticinfectionsSocioeconomicfactorsFamilysizeDietanddrugsObesityAsthmaDiagnosisHistoryandpatternsofsymptomsPhysicalexaminationMeasurementsoflungfunctionMeasurementsofallergicstatustoidentifyriskfactorsClassificationofSeverityCLASSIFYSEVERITYClinicalFeaturesBeforeTreatmentSymptomsNocturnalSymptomsFEV1orPEFSTEP4SeverePersistentSTEP3ModeratePersistentSTEP2MildPersistentSTEP1IntermittentContinuousLimitedphysicalactivityDailyAttacksaffectactivity1timeaweekbut1timeaday1timeaweekAsymptomaticandnormalPEFbetweenattacksFrequent1timeweek2timesamonth2timesamonth60%predictedVariability30%60-80%predictedVariability30%80%predictedVariability20-30%80%predictedVariability20%Thepresenceofonefeatureofseverityissufficienttoplacepatientinthatcategory.Six-PartAsthmaManagementProgram1.Educatepatientstodevelopapartnershipinasthmamanagement2.Assessandmonitorasthmaseveritywithsymptomreportsandmeasuresoflungfunctionasmuchaspossible3.Avoidexposuretoriskfactors4.Establishmedicationplansforchronicmanagementinchildrenandadults5.Establishindividualplansformanagingexacerbations6.Provideregularfollow-upcareSix-partAsthmaManagementProgramGoalsofLong-termManagementAchieveandmaintaincontrolofsymptomsPreventasthmaepisodesorattacksMaintainpulmonaryfunctionasclosetonormallevelsaspossibleMaintainnormalactivitylevels,includingexerciseAvoidadverseeffectsfromasthmamedicationsPreventdevelopmentofirreversibleairflowlimitationPreventasthmamortalitySix-partAsthmaManagementProgramControlofAsthmaMinimal(ideallyno)chronicsymptomsMinimal(infrequent)exacerbationsNoemergencyvisitsMinimal(ideallyno)needforasneededuseof2-agonistNolimitationsonactivities,includingexercisePEFcircadianvariationoflessthan20percent(Near)normalPEFMinimal(orno)adverseeffectsfrommedicineSix-PartAsthmaManagementProgramThemosteffectivemanagementistopreventairwayinflammationbyeliminatingthecausalfactorsAsthmacanbeeffectivelycontrolledinmostpatients,althoughitcannotbecuredThemajorfactorscontributingtoasthmamorbidityandmortalityareunder-diagnosisandinappropriatetreatment.Six-PartAsthmaManagementProgramAnyasthmamoreseverethanintermittentasthmaismoreeffectivelycontrolledbytreatmenttosuppressandreverseairwayinflammationthanbytreatmentonlyofacutebronchoconstrictionandsymptomsTypicalSpirometric(FEV1)Tracings1Time(sec)2345FEV1VolumeNormalSubjectAsthmatic(AfterBronchodilator)Asthmatic(BeforeBronchodilator)Note:
EachFEV1curverepresentsthehighestofthreerepeatmeasurementsASimpleIndexofPEFVariationPEF(L/min)300400500600700800Days7014LowestmorningPEF(570)HighestPEF(670)MorningPEFEveningPEFMinimummorningPEF(%recentbest):
570/670=85%(FromReddel,H.K.etal.1995)Six-partAsthmaManagementProgramPart3:
AvoidExposuretoRiskFactorsMethodstopreventonsetofasthmaarenotyetavailablebutthisremainsanimportantgoalMeasurestoreduceexposuretocausesofasthmaexacerbations(e.g.allergens,pollutants,foodsandmedications)shouldbeimplementedwheneverpossibleSix-partAsthmaManagementProgramPart3:
AvoidExposuretoRiskFactorsReduceexposuretoindoorallergensAvoidtobaccosmokeAvoidvehicleemissionIdentifyirritantsintheworkplaceExploreroleofinfectionsonasthmadevelopment,especiallyinchildrenandyounginfantsPart4:
Long-termAsthmaManagementPharmacologicTherapyControllerMedications:
InhaledglucocorticosteroidsSystemicglucocorticosteroidsCromonesMethylxanthinesLong-actinginhaled2-agonistsLong-actingoral2-agonistsLeukotrienemodifiersPart4:
Long-termAsthmaManagementPharmacologicTherapyRelieverMedications:
Rapid-actinginhaled2-agonistsSystemicglucocorticosteroidsAnticholinergicsMethylxanthinesShort-actingoral2-agonistsPart4:
Long-termAsthmaManagementStepwiseApproachtoAsthmaTherapy-AdultsReliever:
Rapid-actinginhaled2-agonistprnController:
DailyinhaledcorticosteroidController:
DailyinhaledcorticosteroidDailylong-actinginhaled2-agonistController:
DailyinhaledcorticosteroidDailylongactinginhaled2-agonistplus(ifneeded)Whenasthmaiscontrolled,reducetherapyMonitorSTEP1:
IntermittentSTEP2:
MildPersistentSTEP3:
ModeratePersistentSTEP4:
SeverePersistentSTEPDownOutcome:
AsthmaControlOutcome:
BestPossibleResultsAlternativecontrollerandrelievermedicationsmaybeconsidered(seetext).Controller:
None-Theophylline-SR-Leukotriene-Long-actinginhaled2-agonist-OralcorticosteroidRecommendedAsthmaMedicationsStep1:
AdultsSeverityDailyControllerMedicationsOtherOptions(inorderofcost)Step1:
IntermittentNoneNoneRelieverMedication:
Rapid-actinginhaled2-agonistprn,notmorethan3-4timesaday.Oncecontrolisachievedandmaintainedforatleast3months,gradualreductionoftherapyshouldbetried.RecommendedAsthmaMedicationsStep2:
AdultsSeverityDailyControllerMedicationsOtherOptions(inorderofcost)Step2:
MildPersistentInhaledglucocorticosteroid(500gBDPorequivalent)Sustained-releasetheophylline,orCromone,orLeukotrienemodifierRelieverMedication:
Rapid-actinginhaled2-agonistprn,notmorethan3-4timesaday.Oncecontrolisachievedandmaintainedforatleast3months,gradualreductionoftherapyshouldbetried.RecommendedAsthmaMedicationsStep3:
AdultsSeverityDailyControllerMedicationsOtherOptions(inorderofcost)Step3:
ModeratepersistentInhaledglucocorticosteroid(2001000gBDPorequivalent)pluslong-actinginhaled2-agonistInhaledglucocorticosteroid(5001000gBDPorequivalent)plussustained-releasetheophylline,orInhaledglucocorticosteroid(5001000gBDPorequivalent)pluslong-actinginhaled2-agonist,orInhaledglucocorticosteroidathigherdoses(1000gBDPorequivalent),orInhaledglucocorticosteroid(5001000gBDPorequivalent)plusleukotrienemodifierRelieverMedication:
Rapid-actinginhaled2-agonistprn,notmorethan3-4timesaday.Oncecontrolisachievedandmaintainedforatleast3months,gradualreductionoftherapyshouldbetried.RecommendedAsthmaMedicationsStep4:
AdultsSeverityDailyControllerMedicationsOtherOptionsStep4SeverepersistentInhaledglucocorticosteroid(1000gBDPorequivalent)pluslong-actinginhaled2-agonistplusoneormoreofthefollowing,ifneeded:
-Sustained-releasetheophylline-Leukotrienemodifier-Long-actingi