This document provides an overview of asthma, including its definition, epidemiology, risk factors, pathogenesis, diagnosis, classification, and management. Some key points: - Asthma is a chronic inflammatory airway disease characterized by variable airflow obstruction and airway hyperresponsiveness leading to recurrent wheezing, breathlessness, chest tightness and coughing. - It affects over 300 million people worldwide and its prevalence is increasing, especially in children. Common risk factors include atopy, air pollution, infections and obesity. - Diagnosis involves assessing symptoms, lung function tests and allergy testing. Severity is classified based on symptoms, lung function and medication needs. - Management follows a six-part asthma

1. Asthma MBBS.weebly.com

2. Beethoven Ludwig van He was a patient with asthma, and died in 1827.

3. Teresa Deng She was also a patient with asthma, and died in 1995.

4. Asthma incidence of children

5. G IN A lobal itiative for sthma

6. Asthma (GINA Workshop) Topics: Definition Epidemiology Risk Factors Pathogenesis & Mechanisms Diagnosis and Classification Six Part Asthma Management Plan

7. Definition of Asthma Asthma is a chronic inflammatory disorder of the airways in which many cells and cellular elements play a role Chronic inflammation causes an associated increase in airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning These episodes are usually associated with widespread but variable airflow obstruction that is often reversible either spontaneously or with treatment

8. Epidemiology Asthma is one of the most common chronic diseases worldwide —1600 millions patients suffered from asthma Prevalence increasing in many countries, especially in children — 1~4% in adult, 3~5% in children in China A major cause of school/work absence An overall increase in severity of asthma increases the pool of patients at risk for death

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

12. Risk Factors for Asthma Host factors: predispose individuals to, or protect them from, developing asthma Environmental factors: influence susceptibility to development of asthma in predisposed individuals, precipitate asthma exacerbations, and/or cause symptoms to persist

13. Risk Factors that Lead to Asthma Development Host Factors Genetic predisposition Atopy Airway hyper- responsiveness Gender Race Environmental Factors Indoor allergens Outdoor allergens Occupational sensitizers Tobacco smoke Air Pollution Respiratory Infections Parasitic infections Socioeconomic factors Family size Diet and drugs Obesity

14. Factors that Exacerbate Asthma Allergens Air Pollutants Respiratory infections Exercise and hyperventilation Weather changes Sulfur dioxide Food, additives, drugs

15. Mechanisms Underlying the Definition of Asthma Risk Factors (for development of asthma) INFLAMMATION Airway Hyperresponsiveness Airflow Obstruction Risk Factors (for exacerbations) Symptoms

17. Asthma Diagnosis History and patterns of symptoms Physical examination Measurements of lung function Measurements of allergic status to identify risk factors

18. Clinical Manifestation of Asthma Recurrent episodes of wheezing Troublesome cough at night Cough or wheeze after exercise Cough, wheeze or chest tightness after exposure to airborne allergens or pollutants Colds “go to the chest” or take more than 10 days to clear

19. Physical Examination Because of variable symptoms, the physical examination of the respiratory system may be normal. Dyspnea, airflow limitation (wheeze), and hyperinflation are likely to be present if patients are examined during symptomatic periods. Silent chest, cyanosis, drowsiness, difficult speaking, tachycardia and use of accessory muscles in severe asthma.

20. Measurement of Lung Function Spirometry: FEV1, FVC,FEV1/FVC Bronchial Provocation Test (BPT) FEV1>70% predicted Histamine,methacholine, or exercise FEV1↓≥20% at a dose of ≤16mg/ml

21. Measurement of Lung Function Bronchial Dilation Test (BDT) FEV1<70% predicted FEV1↑≥12% and 200ml, FVC↑≥15% and 200ml, after inhaling a short-acting bronchodilator

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

23. Measurement of Lung Function Peak Expiratory Flow (PEF) and PEF Variation. PEF Variation ≥20%

24. Arterial blood gas Respiratory alkalosis, during a mile asthma exacerbation Respiratory acidosis and hypoxemia, during a severe asthma exacerbation

25. Measurement of Allergic Status Skin test Measurement of specific IgE in serum

26. Standards of Diagnosis Recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning Dyspnea, airflow limitation (wheeze), and hyperinflation are likely to be present if patients are examined during symptomatic periods These episodes and symptoms are often reversible either spontaneously or with treatment Exclude other diseases that manifested with similar symptoms At least one or more of the following three: Bronchial Provocation Test (BPT) Bronchial Dilation Test (BDT) Peak Expiratory Flow (PEF) Variation

27. Differential Diagnosis Congestive Heart Failure Pseudoasthma caused by vocal cord dysfunction Chronic bronchitis & COPD Lung cancer

28. Definition of COPD Chronic obstructive pulmonary disease (COPD) is a disease state characterized by airflow limitation that is not fully reversible . The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. GOLD 2004

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

30. Classification of Severity Asthma severity is classified by the presence of clinical features before treatment is started and/or by the amount of daily medication required for optimal treatment

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.

32. Classification of Severity

33. Classification of severity of asthma exacerbation breathlessness RR HR PEF/FEV1 PaO2 PaCO2 SaO2 Mild With activity ↑ <100 >80% normal <45 >95 Moderate With talking ↑ 100~120 60-80% 60~80 <45 91~95 Severe At rest >30 >120 <60% <60 >45 <91 Impending respiratory failure Consciousness Relative bradycardia <60 >45 <91

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

35. Six-part Asthma Management Program Goals of Long-term Management Achieve and maintain control of symptoms Prevent asthma episodes or attacks Maintain pulmonary function as close to normal levels as possible Maintain normal activity levels, including exercise Avoid adverse effects from asthma medications Prevent development of irreversible airflow limitation Prevent asthma mortality

36. Six-part Asthma Management Program Control of Asthma Minimal (ideally no) chronic symptoms Minimal (infrequent) exacerbations No emergency visits Minimal (ideally no) need for “as needed” use of β 2 -agonist No limitations on activities, including exercise PEF circadian variation of less than 20% (Near) normal PEF Minimal (or no) adverse effects from medicine

37. . Six-Part Asthma Management Program The most effective management is to prevent airway inflammation by eliminating the causal factors Asthma can be effectively controlled in most patients, although it can not be cured The major factors contributing to asthma morbidity and mortality are under-diagnosis and inappropriate treatment Any asthma more severe than intermittent asthma is more effectively controlled by treatment to suppress and reverse airway inflammation than by treatment only of acute bronchoconstriction and symptoms

38. Six-part Asthma Management Program Part 1: Educate Patients to Develop a Partnership Educate continually Include the family Provide information about asthma Provide training on self-management skills Emphasize a partnership among health care providers, the patient, and the patient’s family

39. Six-part Asthma Management Program Part 2: Assess and Monitor Asthma Severity with Symptom Reports and Measures of Lung Function Symptom reports Use of reliever medication Nighttime symptoms Activity limitations Spirometry for initial assessment. Peak Expiratory Flow for follow-up: Assess severity Assess response to therapy PEF monitoring at home Important for those with poor perception of symptoms Daily measurement recorded in a diary Assesses the severity and predicts worsening Guides the use of a zone system for asthma self-management Arterial blood gas for severe exacerbations

40. Six-part Asthma Management Program Part 3: Avoid Exposure to Risk Factors Reduce exposure to indoor allergens Avoid tobacco smoke Avoid vehicle emission Identify irritants in the workplace Explore role of infections on asthma development, especially in children and young infants

41. Six-part Asthma Management Program Part 4: Establish Medication Plans for Long-Term Asthma Management A stepwise approach to pharmacological therapy is recommended The aim is to accomplish the goals of therapy with the least possible medication Although in many countries traditional methods of healing are used, their efficacy has not yet been established and their use can therefore not be recommended

42. Part 4: Long-term Asthma Management Stepwise Approach to Asthma Therapy The choice of treatment should be guided by: Severity of the patient’s asthma Patient’s current treatment Pharmacological properties and availability of the various forms of asthma treatment Economic considerations Cultural preferences and differing health care systems need to be considered .

43. Part 4: Long-term Asthma Management Pharmacologic Therapy Controller Medications: Inhaled glucocorticosteroids Systemic glucocorticosteroids Cromones Methylxanthines Long-acting inhaled β 2 -agonists Long-acting oral β 2 -agonists Leukotriene modifiers

44. Part 4: Long-term Asthma Management Pharmacologic Therapy Reliever Medications: Rapid-acting inhaled β 2 -agonists Systemic glucocorticosteroids Anticholinergics Methylxanthines Short-acting oral β 2 -agonists

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48. Part 4: Long-term Asthma Management Stepwise Approach to Asthma Therapy - Adults Reliever: Rapid-acting inhaled β 2 -agonist prn Controller: Daily inhaled corticosteroid Controller: Daily inhaled corticosteroid Daily long-acting inhaled β 2 -agonist Controller: Daily inhaled corticosteroid Daily long –acting inhaled β 2 -agonist plus (if needed) When asthma is controlled, reduce therapy Monitor STEP 1: Intermittent STEP 2: Mild Persistent STEP 3: Moderate Persistent STEP 4: Severe Persistent STEP Down Outcome: Asthma Control Outcome: Best Possible Results Alternative controller and reliever medications may be considered (see text). Controller: None -Theophylline- SR -Leukotriene -Long-acting inhaled β 2 - agonist -Oral corticosteroid

49. Stepwise Approach to Asthma Therapy: Adults Step 1: Intermittent Asthma None required Rapid-acting inhaled  2 -agonist for symptoms (but < once a week) Rapid-acting inhaled  2 -agonist, cromone, or leukotriene modifier before exercise or exposure to allergen Continuously review medication technique, compliance and environmental control Review treatment every three months. Step up if control is not achieved; step down if control is sustained for at least 3 months Preferred treatments are in bold print Daily Controller Medications Reliever Medications

50. Inhaled glucocorticosteroid (< 500 μg BDP or equivalent) Other options ( order by cost ): sustained-release theophylline, or Cromone, or leukotriene modifier Rapid-acting inhaled  2 -agonist for symptoms (but < 3-4 times/day) Other options: inhaled anticholinergic, or short-acting oral  2 -agonist, or short-acting theophylline Continuously review medication technique, compliance and environmental control. Review treatment every three months Step up if control is not achieved; Step down if control is sustained for at least 3 months Preferred treatments are in bold print Stepwise Approach to Asthma Therapy: Adults Step 2: Mild Persistent Asthma Daily Controller Medications Reliever Medications

51. Inhaled glucocorticosteroid, (200 – 500 μg BDP or equivalent) plus long-acting inhaled β 2 agonist Other options (order by cost) : Inhaled glucocorticosteroid (500 – 1000 μg BDP equivalent) plus sustained-release theophylline, or Inhaled glucocorticosteroid (500 – 1000 μg BDP equivalent) plus long-acting inhaled β 2 - agonist, or inhaled glucocorticosteroid at higher doses (> 1000 μg BDP equivalent), or Inhaled glucocorticosteroid (500 – 1000 μg BDP equivalent) plus leukotriene modifier Rapid-acting inhaled  2 -agonist for symptoms (but < 3 - 4 times/day) Other options: inhaled anticholinergic o r short-acting oral  2 -agonist or short-acting theophylline Continuously review medication technique, compliance and environmental control. Review treatment every three months. Step up if control is not achieved; Step down if control is sustained for at least 3 months. Preferred treatments are in bold print. Stepwise Approach to Asthma Therapy: Adults Step 3: Moderate Persistent Asthma Daily Controller Medications Reliever Medications

52. Inhaled glucocorticosteroid, (> 1000 μg BDP or equivalent) plus long-acting inhaled β 2 agonist plus one or more of the following, if needed (order by cost) : sustained-release theophylline, or leukotriene modifier or oral glucocorticosteroid Rapid-acting inhaled  2 -agonist for symptoms (but < 3-4 times/day) Other options: inhaled anticholinergic o r short-acting oral  2 -agonist or short-acting theophylline Continuously review medication technique, compliance and environmental control. Review treatment every three months. Step up if control is not achieved; Step down if control is sustained for at least 3 months. Preferred treatments are in bold print. Stepwise Approach to Asthma Therapy: Adults Step 4: Severe Persistent Asthma Daily Controller Medications Reliever Medications

53. Six-part Asthma Management Program Part 5: Establish Plans for Managing Exacerbations Primary therapies for exacerbations: Repetitive administration of rapid-acting inhaled β 2 -agonist Early introduction of systemic glucocorticosteroids Oxygen supplementation Closely monitor response to treatment with serial measures of lung function

54. Six-part Asthma Management Program Part 5: Managing Severe Asthma Exacerbations Severe exacerbations are life-threatening medical emergencies Care must be expeditious and treatment is often most safely undertaken in a hospital or hospital-based emergency department

55. 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

56. Six-part Asthma Management Program Part 6: Provide Regular Follow-up Care Continual monitoring is essential to assure that therapeutic goals are met. Frequent follow-up visits are necessary to review: Home PEF and symptom records Techniques in use of medications Risk factors and their control Once asthma control is established, follow-up visits should be scheduled (at 1 to 6 month intervals as appropriate)

57. Six-part Asthma Management Program: Summary Asthma can be effectively controlled, although it cannot be cured Effective asthma management programs include education, objective measures of lung function, environmental control, and pharmacologic therapy A stepwise approach to pharmacologic therapy is recommended. The aim is to accomplish the goals of therapy with the least possible medication

58. Six-part Asthma Management Program: Summary (continued) Anything more than mild, occasional asthma is more effectively controlled by suppressing inflammation than by only treating acute bronchospasm The availability of varying forms of treatment, cultural preferences, and differing health care systems need to be considered

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