支气管哮喘BronchialAsthma.ppt

支气管哮喘支气管哮喘BronchialAsthmaOutline Burden of Asthma Definition of Asthma Etiology and Mechanism Diagnosis and Classification Asthma Medications Asthma management and PreventionBurden of Asthma Health care expenditures very highHealth care expenditures very high Developed economies might expect to Developed economies might expect to spend 1-2 percent of total health care spend 1-2 percent of total health care expenditures on asthma.Developing expenditures on asthma.Developing economies likely to face increased demandeconomies likely to face increased demand Poorly controlled asthma is expensive;Poorly controlled asthma is expensive;investment in prevention medication likely investment in prevention medication likely to yield cost savings in emergency careto yield cost savings in emergency careAsthma Prevalence and MortalitySourceSource:Masoli M et al.Allergy 2004:Masoli M et al.Allergy 2004Epidemiology of AsthmaProportion of population with asthma(%)Case fatality rate per 100,000 asthmaticsDefinition of AsthmaDefinition of AsthmaA chronic inflammatory disorder of the airwaysA chronic inflammatory disorder of the airwaysMany cells and cellular elements play a roleMany cells and cellular elements play a roleChronic inflammation is associated with airway Chronic inflammation is associated with airway hyperresponsiveness that leads to recurrent hyperresponsiveness that leads to recurrent episodes of wheezing,breathlessness,chest episodes of wheezing,breathlessness,chest tightness,and coughingtightness,and coughingWidespread,variable,and often reversible Widespread,variable,and often reversible airflow limitationairflow limitationSource:Peter J.Barnes,MDSource:Peter J.Barnes,MDMechanismsSource:Peter J.Barnes,MDSource:Peter J.Barnes,MDAsthma InflammationSource:Peter J.Barnes,MDSource:Peter J.Barnes,MDAsthma InflammationRisk Factors for Asthma Host factors:Host factors:predispose individuals to,predispose individuals to,or protect them from,developing or protect them from,developing asthmaasthma Environmental factors:Environmental factors:influence influence susceptibility to development of asthma susceptibility to development of asthma in predisposed individuals,precipitate in predisposed individuals,precipitate asthma exacerbations,and/or cause asthma exacerbations,and/or cause symptoms to persistsymptoms to persistFactors that Influence Asthma Development and ExpressionHost FactorsHost Factors GeneticGenetic -Atopy -Atopy -Airway -Airway hyperresponsiveness hyperresponsiveness GenderGender ObesityObesityEnvironmental FactorsEnvironmental Factors Indoor allergensIndoor allergens Outdoor allergens Outdoor allergens Occupational sensitizers Occupational sensitizers Tobacco smoke Tobacco smoke Air pollution Air pollution Respiratory Infections Respiratory Infections Diet DietMajor Indoor Asthma TriggersIs it Asthma?Is it Asthma?Recurrent episodes of wheezingTroublesome cough at nightCough or wheeze after exerciseCough,wheeze or chest tightness after exposure to airborne allergens or pollutantsColds“go to the chest”or take more than 10 days to clearAsthma Diagnosis History and patterns of symptoms History and patterns of symptoms-Episodic symptoms after an incidental allergen-Episodic symptoms after an incidental allergen exposure,seasonal variability of symptoms;exposure,seasonal variability of symptoms;-Positive family history of asthma and atopic disease;-Positive family history of asthma and atopic disease;-Symptoms improved by appropriate asthma-Symptoms improved by appropriate asthma treatment;treatment;Physical examination Physical examination-May be normal;-May be normal;-The most usual abnormal physical finding is-The most usual abnormal physical finding is wheezing on auscultation;wheezing on auscultation;Asthma DiagnosisMeasurements of lung functionMeasurements of lung function -Spirometry -Spirometry -Peak expiratory flow -Peak expiratory flowMeasurement of airway responsiveness Measurement of airway responsiveness Measurements of allergic status to identify risk Measurements of allergic status to identify risk factorsfactorsExtra measures may be required to diagnose Extra measures may be required to diagnose asthma in children 5 years and younger and the asthma in children 5 years and younger and the elderlyelderlyTypical Spirometric(FEVTypical Spirometric(FEV11)TracingsTracings1 1Time(sec)Time(sec)2 23 34 45 5FEVFEV11VolumeVolumeNormal SubjectNormal SubjectAsthmatic(After Bronchodilator)Asthmatic(After Bronchodilator)Asthmatic(Before Bronchodilator)Asthmatic(Before Bronchodilator)Note:Each FEV1 curve represents the highest of three repeat measurementsMeasuring Variability of Peak Expiratory FlowMeasuring Airway ResponsivenessEtiologic Diagnosis Identify environmental factors Allergen challenge testAllergen challenge test Skin prick testSkin prick test Specific IgESpecific IgEDifferential Diagnosis Other forms of obstructive lung disease,Other forms of obstructive lung disease,particularly COPD particularly COPD Non-respiratory causes of symptoms Non-respiratory causes of symptoms(e.g.,left ventricular failure)(e.g.,left ventricular failure)Non-obstructive forms of lung disease Non-obstructive forms of lung disease(e.g.,diffuse parenchymal lung disease)(e.g.,diffuse parenchymal lung disease)Upper airway obstruction and inhaled Upper airway obstruction and inhaled foreign bodiesforeign bodiesController MedicationsController MedicationsInhaled glucocorticosteroidsInhaled glucocorticosteroidsLeukotriene modifiersLeukotriene modifiersLong-acting inhaled Long-acting inhaled 22-agonists-agonistsSystemic glucocorticosteroids Systemic glucocorticosteroids TheophyllineTheophyllineCromonesCromonesLong-acting oral Long-acting oral 22-agonists-agonistsAnti-Anti-IgEIgESystemic glucocorticosteroidsSystemic glucocorticosteroidsEstimate Comparative Daily Dosages for Estimate Comparative Daily Dosages for Inhaled Glucocorticosteroids by AgeInhaled Glucocorticosteroids by AgeDrug Drug Low Daily Dose(Low Daily Dose(g)Medium Daily Dose(g)Medium Daily Dose(g)High Daily g)High Daily Dose(Dose(g)g)5 y Age 5 y Age 5 y Age 5 y 5 y Age 5 y Age 5 y 5 y Age 12yrs with mild persistent asthma.Further study neededPharmacologic TherapyPharmacologic TherapyQuick relief medicationsShort acting beta2-agonists-relief of acute symptoms Anticholinergics-may provide additive benefit to beta2 drugs in severe exacerbation.May be alternative to beta2-agonistsSystemic steroids-moderate-to-severe persistent asthma in acute exacerbations or to prevent recurrence of exacerbationsPharmacologic TherapyPharmacologic TherapyTreatment/Long Term ControlTreatment/Long Term ControlCorticosteroidsMost potent and effectiveReduction in symptoms,improvement in PEF and spirometry,diminished airway hyperresponsiveness,prevention of exacerbations,possible prevention of airway wall remodelingSuppresses:cytosine production,airway eosinophilic recruitment,chemical mediators Long-acting beta-2 agonistsRelax airway smooth muscleDuration of action 12 hrsNot used in acute exacerbationsAdjunct to anti-inflammatory tx for long-term symptom control especially nocturnal symptomsTreatment/Long Term ControlTreatment/Long Term ControlLeukotriene modifiersLeukotrienes are potent biochemical mediators released from mast cells,eosinophils,and basophils that:contract bronchial smooth muscleincrease vascular permeabilityincrease mucus secretionsattract&activate inflammatory cells in airwaysTreatment/Long Term ControlTreatment/Long Term ControlAsthma Treatment/Quick ReliefAsthma Treatment/Quick ReliefShort-acting beta2 agonists Relax airway smooth muscle and increase in airflow in 1 canister/mo indicates inadequate control and indicates need to intensify anti-inflammatory txRegularly scheduled use NOT recommendedAnticholinergics Cholinergic innervation important in regulation of airway smooth muscle toneIpratropium bromide(quaternary derivative of atropine without its side effects)Additive benefit with inhaled beta 2-agonists in severe asthma exacerbationsEffectiveness in long-term management not demonstratedAsthma Treatment/Quick ReliefAsthma Treatment/Quick ReliefSystemic steroidsspeed resolution of airflow obstructionreduce rate of relapseMedications to reduce oral steroid dependenceTroleandomycin,cyclosporin,gold,methotrexate,IV immunoglobulin,dapsone,hydroxychloroquine Asthma Treatment/Quick ReliefAsthma Treatment/Quick ReliefAsthma Medication EquipmentMethods of Delivery Medications may be given by:-Metered Dose Inhaler(MDI)-Dry Powdered Inhaler(DPI)-Nebulizer-OrallyImportant to review technique for all delivery methodsClinical Control of Asthma No(or minimal)*daytime symptoms No limitations of activity No nocturnal symptoms No(or minimal)need for rescue medication Normal lung function No exacerbations_*Minimal=twice or less per weekLevels of Asthma ControlGoals of Long-term Management Achieve and maintain control of symptomsAchieve and maintain control of symptoms Maintain normal activity levels,including Maintain normal activity levels,including exerciseexercise Maintain pulmonary function as close to Maintain pulmonary function as close to normal levels as possiblenormal levels as possible Prevent asthma exacerbationsPrevent asthma exacerbations Avoid adverse effects from asthma Avoid adverse effects from asthma medicationsmedications Prevent asthma mortalityPrevent asthma mortalitycontrolledpartly controlleduncontrolledexacerbationLEVEL OF CONTROLLEVEL OF CONTROLmaintain and find lowest controlling stepconsider stepping up to gain controlstep up until controlledtreat as exacerbationTREATMENT OF ACTIONTREATMENT OF ACTIONTREATMENT STEPSREDUCEINCREASESTEP1STEP2STEP3STEP4STEP5REDUCEINCREASE Exacerbations of asthma are episodes of Exacerbations of asthma are episodes of progressive increase in shortness of breath,progressive increase in shortness of breath,cough,wheezing,or chest tightnesscough,wheezing,or chest tightness Exacerbations are characterized by decreases Exacerbations are characterized by decreases in expiratory airflow that can be quantified and in expiratory airflow that can be quantified and monitored by measurement of lung function monitored by measurement of lung function(FEV(FEV11 or PEF)or PEF)Severe exacerbations are potentially life-Severe exacerbations are potentially life-threatening and treatment requires close threatening and treatment requires close supervisionsupervisionManage Asthma ExacerbationsManage Asthma ExacerbationsPrimary therapies for exacerbations:Primary therapies for exacerbations:Repetitive administration of rapid-acting inhaled Repetitive administration of rapid-acting inhaled 22-agonist-agonist Early introduction of systemic Early introduction of systemic glucocorticosteroidsglucocorticosteroids Oxygen supplementationOxygen supplementationClosely monitor response to treatment with serialClosely monitor response to treatment with serialmeasures of lung functionmeasures of lung functionManage Asthma ExacerbationsManage Asthma ExacerbationsAllergen-specific ImmunotherapyAllergen-specific Immunotherapy Greatest benefit of specific immunotherapy Greatest benefit of specific immunotherapy using allergen extracts has been obtained in using allergen extracts has been obtained in the treatment of allergic rhinitisthe treatment of allergic rhinitisThe role of specific immunotherapy in asthma is The role of specific immunotherapy in asthma is limitedlimitedSpecific immunotherapy should be considered Specific immunotherapy should be considered only after strict environmental avoidance and only after strict environmental avoidance and pharmacologic intervention,including inhaled pharmacologic intervention,including inhaled glucocorticosteroids,have failed to control glucocorticosteroids,have failed to control asthmaasthmaPerform only by trained physicianPerform only by trained physicianAsthma Management and Prevention ProgramAsthma Management and Prevention ProgramAsthma Management and Prevention ProgramSpecial ConsiderationsSpecial ConsiderationsSpecial considerations are required toSpecial considerations are required tomanage asthma in relation to:manage asthma in relation to:PregnancyPregnancy SurgerySurgery Rhinitis,sinusitis,and nasal polypsRhinitis,sinusitis,and nasal polyps Occupational asthmaOccupational asthma Respiratory infectionsRespiratory infections Gastroesophageal refluxGastroesophageal reflux Aspirin-induced asthmaAspirin-induced asthma Anaphylaxis and AsthmaAnaphylaxis and Asthma1.1.Develop Patient/Doctor Develop Patient/Doctor PartnershipPartnership2.2.Identify and Reduce Exposure Identify and Reduce Exposure to Risk Factorsto Risk Factors3.3.Assess,Treat and Monitor Assess,Treat and Monitor AsthmaAsthma4.4.Manage Asthma ExacerbationsManage Asthma Exacerbations5.5.Special ConsiderationsSpecial ConsiderationsAsthma Management and PreventionAsthma Management and PreventionProgram:Five ComponentsProgram:Five ComponentsRevised 2006Asthma can be effectively controlled in most Asthma can be effectively controlled in most patients by intervening to suppress and reverse patients by intervening to suppress and reverse inflammation as well as treating inflammation as well as treating bronchoconstriction and related symptomsbronchoconstriction and related symptomsAlthough there is no cure for asthma,Although there is no cure for asthma,appropriate management that includes a appropriate management that includes a partnership between the physician and the partnership between the physician and the patient/family most often results in the patient/family most often results in the achievement of controlachievement of controlAsthma Management and Asthma Management and Prevention Program:Prevention Program:SummarySummary A stepwise approach to pharmacologic A stepwise approach to pharmacologic therapy is recommended.The aim is to therapy is recommended.The aim is to accomplish the goals of therapy with the accomplish the goals of therapy with the least possible medicationleast possible medication The availability of varying forms of The availability of varying forms of treatment,cultural preferences,and treatment,cultural preferences,and differing health care systems need to be differing health care systems need to be considered considered Asthma Management and Asthma Management and Prevention Program:Prevention Program:SummarySummary 谢谢