7.支气管哮喘(双语)

Asthma,ZhongminQiuDepartmentofRespiratoryMedicineTongjiHospitalofTongjiUniversity,WhatIsAsthma?,Asthmaisadiseasethatcharacterizedby:AirwayobstructionthatisreversibleeitherspontaneouslyorwithtreatmentchronicairwayinflammationIncreasedairwayresponsivenesstoavarietyofstimuliInflammationcausesrecurrentepisodesofwheezing,breathlessness,chesttightnessandcoughing,particularlyatnightorearlymorning,Epidemiology,17-20millionAmericans(6-10%prevalence)1%estimatedprevalenceinmainlandofChina10millionmedicalvisits2millionemergencyvisits0.5millionhospitalization5000deathsannuallyMajorcauseofschoolandworkabsenceAtleast12billionperyearIncreasingburdenforyears,ImpactOfAsthmaOnPatients,Psychosocial:Poorself-esteemAnxietyaboutasthmaFearofbecomingillatout-doorAnxietyaboutexerciseFearofbeingdifferent,DidYouKnow.,Asthmakillspeopleequallyregardlessofseveritylevel1/3ofdeathsareinthosewithmildasthma1/3ofdeathsareinthosewithmoderateasthma1/3ofdeathsareinthosewithsevereasthma,WhatCausesAsthma?,Asthmamaybecausedbygenetic,immuneand/orenvironmentalfactors,andisoftenassociatedwitheczemaandallergiesWedonotunderstandallofthecausesofasthmaoritsincreasingprevalenceItboilsdownto“Wejustdontreallyknowforsure”,WhatCausesAsthma,Ofthe17millionasthmasufferersintheUS,10Million(approx.60%)haveallergicasthma.3millionofthosearechildrenExposuretocertainallergenstriggerasthmasymptomstobeginExposuretocertainirritantscanalsosetanasthmaepisodeinmotion,TriggersandIrritants,CommonAllergens(Triggers),SeasonalPollensAnimaldandersaliva/urineDustMitesCockroaches/Mice/RatdroppingsandurineMoldSomemedicationsSomeFoods,CommonIrritants(Triggers),ExerciseColdAirChalkDustViral/upperrespiratoryinfectionsAirpollutionTobaccosmokeorsecondhandsmoke,ChemicalirritantsandstrongsmellsStrongemotionalfeelingsDieselfumesCleaningsupplies,RV-InducedAirwayInflammation,VirusescauseasthmaexacerbationsRVscause60%ofvirus-inducedexacerbationsofasthmaRVsdirectlyinfectthebronchialairwaysTheresponsetoviralinfectionisshapedbythehostsantiviralresponse,RV-InducedAsthma,Nakano,Y.etal.Chest2002;122:271S-a-275S-a,Pathophysiologicschemaforthedevelopmentofasthma,TheAllergicReaction,TheAsthmaCascade,MediatorPhases,Early-phasereactioncausedbymediatorrelease,usuallypeakswithinanhourafterinitialexposuretotheallergen.Threetofourhoursafteranacuteasthmaepisode,alate-phasereactionmayoccurandmaylastupto24hours,TheEndResultsOfTheCascade,LocalizedmucosaledemainthewallsofthesmallbronchiolesSecretionofthickmucusintothebronchiolarlumens(Clogsandnarrowstheairways)Spasticcontractionofbronchiolarsmoothmuscle,NormalBronchioleInflamedBronchiolewithMucus,AirwayObstruction,Copyright3MPharmaceuticals2004,RemodelingPhases,Airwaywallthickening.SubepithelialfibrosisSmoothmusclehyperplasiaandhypertrophyMyofibroblasthyperplasiaMucusmetaplasia,Vignola,A.M.etal.Chest2003;123:417S-a-422S-a,Increasedthicknessofthebasementmembrane(arrow),andenhancedandabnormaldepositionoffibronectin,whichisidentifiedbyimmunohistochemistryusingaspecificmonoclonalantibody(dashedarrow),inthebronchialsubmucosa,Increasedthicknessofthebasementmembrane,andenhancedandabnormaldepositionofcollageninthebronchialsubmucosa,ALotGoingOnBeneathTheSurface,CommonSymptomsOfAsthma,Frequentcough,especiallyatnightShortnessofbreathorrapidbreathingChesttightnessChestpainWheezingFatigue,EarlySignsOfAnAsthma“Episode”,MildcoughDropinPeakFlowreadingItchy,wateryorglassyeyesItchy,scratchyorsorethroatRunnynose,StomachacheHeadacheSneezingCongestionRestlessnessDarkcirclesundereyesIrritability,MeasuresOfAssessmentAndMonitoring,TwoAspects:InitialassessmentanddiagnosisofasthmaPeriodicassessmentandmonitoring,InitialAssessment&DiagnosisofAsthma,DeterminesThat:PatienthasahistoryorpresenceofepisodicsymptomsofairflowobstructionAirflowobstructionisatleastpartiallyreversibleAlternativediagnosesareexcluded,MethodsforEstablishingDiagnosis,DetailedmedicalhistoryPhysicalexam:wheezeandrhonchus(rhonchi)Spirometrytodemonstratereversibility,Diagnosisofasthma,Objectivemeasurements20%diurnalvariationon3daysinaweekfor2weeksonPEFdiaryorFEV115%(and200ml)increaseaftershortacting2agonistorsteroidtabletsorFEV115%decreaseafter6minutesofrunningexercisehistamineormethacholinechallengeindifficultcases,Symptoms(episodic/variable)wheezeshortnessofbreathchesttightnesscough,Signsnone(common)wheezediffuse,bilateral,expiratory(inspiratory)tachypnea,Helpfuladditionalinformationpersonal/familyhistoryofasthmaoratopyhistoryofworseningafteraspirin/NSAID,blockeruserecognisedtriggerspollens,dust,animals,exercise,viralinfections,chemicals,irritantspatternandseverityofsymptomsandexacerbations,Considerthediagnosisofasthmainpatientswithsomeorallofthesefeatures,AsthmaLungAssessmentSpirometry,SpirometryisGoldstandardtoassistinasthmadiagnosisPerformedbeforeandafterbronchodilatordosetolookforairwayobstructionreversibilityCanalsobedonewithhistamineormethylcholinechallenge,oranexercisechallengeinthecaseofexercise-inducedasthma,IsAirflowObstructionAtLeastPartiallyReversible?,UsespirometrytoestablishairflowobstructionFEV115%andatleast200mLafterusingashort-actinginhaledbeta2-agonist,PeakExpiratoryFlowVariability,AnanotherwaytoevaluateairwayobstructionThereisthedifferencebetweenthemorningandeveningPEFreadingsPEFreadingstendtobehigherintheeveningthaninthemorning,PeakFlowMeters,Differentialdiagnosisofasthma,Someofsymptomsofasthmaaresharedwithdiseasesofothersystems,Numerousrelativelycommonlungdiseases,Needtodifferentiatefrominfectionsandrestrictivelungdisorders,andbetweenlocalandgeneralisedobstruction,AsthmaSeverityLevels,MildIntermittentMildPersistentModeratePersistentSeverePersistent,AsthmaSeverityLevelsBySymptoms,MildIntermittent-Sx2x/weekbut2nights/monthModeratePersistent-SxeverydaySx1night/weekSeverePersistent-ContinualdaytimeSxFrequentSxatnight,MildIntermittent,Symptoms2days/weekwithnighttimesymptoms2nights/monthAsymptomaticwithnormalpeakflowsbetweenexacerbationsExacerbationsarebrief(hourstoafewdays)PeakFlows80%predictedwithvariability2days/weekbut1x/daywithnighttimesymptomsgreaterthan2nights/monthExacerbationsmayaffectactivityPeakflow80%predictedwithvariabilityof30%Activityisaffectedandexacerbationsmaylastdays,SeverePersistent,ContinualdaytimesymptomswithfrequentnighttimesymptomsVerylimitedphysicalactivityFrequentexacerbationsPeakflows60%ofpredictedandvariabilityofmorethan30%Treatmentinvolvesacombinationofmanydrugtherapies,GoalsOfAsthmaTherapy,PreventchronicandtroublesomesymptomsMaintain“normal”pulmonaryfunctionMaintainnormalactivitylevels-includingexerciseandotherphysicalactivityMinimizetheneedforemergencyroom/urgentcarevisitsorhospitalizations,GoalsOfAsthmaTherapyContinued,PreventrecurrentexacerbationsofsymptomsProvideoptimalpharmacotherapywithminimalornoadverseeffectsSatisfythepatientsandthefamilysgoalsforasthmacare,StepwiseApproachToAsthmaTherapy,Outcome:BestPossibleResults,BronchodilatorsRelaxingbronchialsmoothmuscletoopenuptheairway.Anti-inflammatoryagentsInhibitingthedevelopmentofairwayinflammationandstoppingongoinginflammation.Incombination,treatandpreventreversibleairwayobstructionandairwayhyperresponsiveness,relievethesymptomanddecreasetheexacerbati