9. Worldwide Variation in Prevalence of Asthma Symptoms International Study of Asthma and Allergies in Children (ISAAC) Lancet 1998;351:1225
10. Increasing Prevalence of Asthma in Children/Adolescents 0 5 10 15 20 25 30 35 1992 1982 1989 1975 1992 1982 1994 1989 1992 1982 1992 1982 1991 1979 1989 1966 Finland (Haahtela et al ) Sweden (Aberg et al ) Japan (Nakagomi et al ) Scotland (Rona et al ) UK (Omran et al ) USA (NHIS) New Zealand (Shaw et al ) Australia (Peat et al ) { Prevalence (%) { { { { { { {
11. 70 60 50 40 30 20 85 86 87 88 89 90 91 92 93 94 Rate/1,000 Persons Year <18 18-44 45-64 65+ Total (All Ages) Age (years) Trends in Prevalence of Asthma By Age, U.S., 1985-1996 95 96 80
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22. Typical Spirometric (FEV 1 ) Tracings 1 Time (sec) 2 3 4 5 FEV 1 Volume Normal Subject Asthmatic (After Bronchodilator) Asthmatic (Before Bronchodilator) Note: Each FEV 1 curve represents the highest of three repeat measurements
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29. Pointers that differentiate asthma from COPD COPD Asthma History Smoker or ex-smoker Nearly all Possibly Symptoms under age 45 Uncommon Often Chronic productive cough Common Uncommon Breathlessness Persistent and progressive Variable Winter bronchitis Common Uncommon Investigations Serial PEF Obstructive picture May be normal Day to day and diurnal variation Reversibility testing Minimal variation Usually<15% or 200ml change Usually>15% or 200ml change
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31. Classification of Severity of chronic stable asthma CLASSIFY SEVERITY Clinical Features Before Treatment Symptoms Nocturnal Symptoms FEV 1 or PEF STEP 4 Severe Persistent STEP 3 Moderate Persistent STEP 2 Mild Persistent STEP 1 Intermittent Continuous Limited physical activity Daily Attacks affect activity > 1 time a week but < 1 time a day < 1 time a week Asymptomatic and normal PEF between attacks Frequent > 1 time a week > 2 times a month 2 times a month 60% predicted Variability > 30% 60 - 80% predicted Variability > 30% 80% predicted Variability 20 - 30% 80% predicted Variability < 20% The presence of one feature of severity is sufficient to place patient in that category.
33. Classification of severity of asthma exacerbation <91 >45 <60 Relative bradycardia Consciousness Impending respiratory failure <91 >45 <60 <60% >120 >30 At rest Severe 91~95 <45 60~80 60-80% 100~120 ↑ With talking Moderate >95 <45 normal >80% <100 ↑ With activity Mild SaO2 PaCO2 PaO2 PEF/FEV1 HR RR breathlessness
34. Six-Part Asthma Management Program 1. Educate patients to develop a partnership in asthma management 2. Assess and monitor asthma severity with symptom reports and measures of lung function as much as possible 3. Avoid exposure to risk factors 4. Establish medication plans for chronic management in children and adults 5. Establish individual plans for managing exacerbations 6. Provide regular follow-up care
56. Emergency Department Management Acute Asthma Respiratory Failure Admit to ICU Good Response Observe for at least 1 hour If Stable, Discharge to Home Initial Assessment History, Physical Examination, PEF or FEV 1 Initial Therapy Bronchodilators; O 2 if needed Incomplete/Poor Response Add Systemic Glucocorticosteroids Good Response Discharge Poor Response Admit to Hospital