Asthma

1. Asthma Dr. GerrardUy

2. Asthma • Asthma is a serious health problem throughout the world, affecting people of all ages • When uncontrolled, asthma can place severe limits on daily life, and is sometimes fatal • In 1993, GINA was introduced

3. What is Asthma • Chronic inflammatory disorder of the airways • Associated with airway hyperresponsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, coughing, particularly at night or early in the morning • Clinical manifestations can be controlled with appropriate treatment

4. What is Asthma • Wheezing is the most common physical finding in asthma • Main physiological feature is episodic airway obstruction characterized by expiratory airflow limitation • Dominant pathological feature is airway inflammation, sometimes associated with structural changes • Strongly associated with atopy

5. Burden of Asthma • Asthma is a problem worldwide with an estimated 300 million affected individuals • Ranges for 1 – 18% of the population in different countries • Annual worldwide deaths from asthma have been estimated at 250,000

6. Factors influencing the development and expression of asthma • Host Factors: • Genetics • Obesity (BMI > 30 kg/m2) • Sex • Environmental Factors: • Allergens • Infections • Occupational sensitizers • Tobacco smoke • Outdoor/Indoor pollution • Diet

7. Mechanism of asthma • Airway inflammation • Remains to be a consistent feature • Persistent even though symptoms are episodic • Inflammation affects all airways but is most pronounced in medium sized bronchi • Inflammatory cells found in asthma • Mast cells • Eosinophils • T lymphocytes • Dendritic cells • Macrophages • Neutrophils

8. Mechanism of asthma • Airway structural cells involved in asthma: • Airway epithelial cells • Airway smooth muscle cells • Endothelial cells • Fibroblast and myofibroblast • Airway nerves

9. Mechanism of asthma • Structural changes in asthma • Subepithelial fibrosis • Airway smooth muscle hypertrophy and hyperplasia • Blood vessels increase in number • Mucus hypersecretion

10. Pathophysiology • Airway narrowing is the common final pathway leading to symptoms and physiological changes in asthma • Airway hyperresponsiveness is the characteristic functional abnormality in asthma

11. Diagnosis • Episodic breathlessness, wheezing, cough, and chest tightness • History of atopy or allergic rhinitis • Symptoms occurring at night • Precipitation by exposure to certain allergens • Resolves/improves after appropriate asthma medication

12. Lung Function Test • Spirometry • Recommended method of measuring airflow limitation and reversibility • Measures FEV1 and FVC • FEV1/FVC is normally > 0.75 – 0.80 • The degree of reversibility in FEV1 is generally accepted as 12% or 200 ml from the pre bronchodilator value

13. Lung Function Test • Peak Expiratory Flow Measurement (PEF) • Measurements are made using a peak flow meter • Relatively inexpensive, portable, ideal for patients in home settings • PEF can underestimate degree of airflow limitation • Most commonly, PEF is measured first thing in the morning before treatment is taken • 60 ml/L or 20% improvement from prebronchodilator suggests a diagnosis of asthma

14. Differential Diagnosis • Children 5 yrs and younger • Transient early wheezing • Persistent early onset wheezing • Late onset wheezing/asthma • Older children and adults • Hyperventilation syndrome • Foreign body aspiration • Vocal cord dysfunction • COPD • heartfailure

16. Treatment • The goal of asthma treatment is to achieve and maintain clinical control • Medications to treat asthma is divided into 2 – Controllers and relievers • Different routes of administration: • Inhaled, orally, parenterally (IV, SC, IM) • The major advantage of inhaled route is that the medication is delivered directly into the airways, producing higher local concentrations with less risk of systemic side effects

17. Controller Medications • Inhaled glucocorticoids • Currently the most effective anti-inflammatory medication for the treatment of persistent asthma • Budesonides, fluticasone, mometasone, etc. • To reach clinical control, add on therapy with another class of drug is preferred over increasing the dose of inhaled glucocorticoids • Side effects: • Oropharyngealcandidiasis • Dysphonia • Coughing from upper airway irritation

18. Controller Medications • Inhaled glucocorticoids • Systemic side effects of long term high dose glucocorticiods: • Easy bruising • Adrenal suppression • Decreased bone mineral density • Cataracts/glaucoma • *there is no evidence that the use of inhaled glucocorticoids increases the risk of pulmonary infections

19. Controller Medications • Leukotriene modifiers • Small and variable bronchodilator effect • Maybe used as an alternative treatment for patients with mild persistent asthma • Usually used as an add on therapy • Less effective compared to long acting B2 agonist as an add on therapy • Montelukast, zileuton, etc

20. Controller Medications • Long acting inhaled B2 agonist • Should not be used as monotherapy because they do not influence airway inflammation • Salmeterol, Formoterol, etc • Side effects: • Cardiovascular stimulation • Skeletal muscle tremor • hypokalemia

21. Controller Medications • Others: • Theophylline • Cromones (Sodium cromoglycate/Nedocromil Na) • Long acting oral B2 agonist (Salbutamol, bambuterol, terbutaline) • Anti IgE (Omalizumab) • Systemic glucocorticoids

22. Reliever Medications • Rapid acting inhaled B2 agonist • Medication of choice for relief of bronchospasm during acute exacerbations of asthma and for pretreatment of exercise induced bronchoconstriction • Salbutamol, formoterol, terbutaline, etc • Side effects: tremor and tachycardia

23. Reliever Medications • Systemic glucocorticoids • Important in the treatment of severe acute attacks • Prevent progression of the exacerbation, reduce the need for referral to emergency departments and hospitalization, reduce morbidity of the illness • Main effect are only evident after 4-6 hrs • Prednisone, hydrocortisone, etc

24. Reliever Medications • Anti-cholinergics • Alternative bronchodilator in patients who experience side effects of B2 agonist • Side effect: dryness of the mouth and bitter taste • Ipatropium bromide

25. Reliever Medications • Others • Theophylline • Rapid acting B2 agonist • Alternative medicine

26. COPD(Chronic Obstructive Pulmonary Disease) Dr. GerrardUy

27. COPD • Major cause of chronic morbidity and mortality throughout the world • GOLD was created to increase awareness of COPD among health professionals, public health authorities, and the general public, and to improve prevention and management through a concerted worldwide effort

28. COPD • Global Initiative for Chronic Obstructive Lung Disease (GOLD) • a disease state characterized by airflow limitation that is not fully reversible • The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lung to noxious particles and gases • Includes: • emphysema, chronic bronchitis, and small airways disease

29. COPD • Emphysema • an anatomically defined condition characterized by destruction and enlargement of the lung alveoli • Chronic Bronchitis • a clinically defined condition with chronic cough and phlegm • Small airways disease • a condition in which small bronchioles are narrowed

30. Symptoms of COPD • Cough • Sputum production • Dyspnea on exertion * chronic cough and sputum production often precede the development of airflow limitation by many years

31. Risk Factors • Cigarette/tobacco Smoking • Intensity: pack years (sticks/day for years) • most highly significant predictor of FEV1 • Occupational Exposures • general exposure to dust at work • coal mining, gold mining, and cotton textile dust

32. Risk Factors • Indoor Air pollution • Biomass fuel used for cooking • Outdoor Air Pollution • Genetic Considerations (alpha 1 antitrypsin deficiency)

33. Natural History • Effect of cigarette smoking depends on intensity, timing during growth, basal function

34. Pathophysiology • Airflow obstruction • Determined by spirometry: FEV1 and FVC • chronically reduced ratio of FEV1/FVC • seldom shows large responses to inhaled bronchodilators • Hyperinflation • "air trapping“ • helps to compensate for airway obstruction

35. Pathophysiology • Gas Exchange • Nonuniform ventilation and ventilation-perfusion mismatching

36. Pathology • Large Airway • Cigarette smoking often results in mucous gland enlargement and goblet cell hyperplasia • proportional to cough and mucus production • Small Airways • major site of increased resistance in most individuals with COPD is in airways 2 mm diameter • goblet cell metaplasia and replacement of surfactant-secreting Clara cells with mucus-secreting and infiltrating mononuclear inflammatory cells

37. Pathology • Lung Parenchyma • destruction of gas-exchanging airspaces • walls become perforated and later obliterated with coalescence of small distinct airspaces into abnormal and much larger airspaces • Macrophages accumulate • Centriacinar emphysema- most frequently associated with cigarette smoking • Panacinar emphysema - usually observed in patients with alpha1AT deficiency

39. Diagnosing COPD • Considered in any patient who has dyspnea, chronic cough with or without sputum production and/or history of exposure to risk factors for the disease • Preform spirometry for confirmation

40. Stages of COPD • Stage 1: Mild COPD • Mild airflow limitation (FEV1/FVC <70%, FEV1 > 80% predicted) • Stage 2: Moderate COPD • Worsening airflow limitation (FEV!/FVC <70%, FEV1 < 80% predicted) • Stage 3: Severe COPD • Further worsening (FEV1/FVC <70%, FEV1 < 50% predicted) • Stage 4: Very severe COPD • FEV1/FVC <70%, FEV1 < 30% predicted or < 50% with chronic respiratory failure

41. Clinical presentation • History • cough, sputum production, and exertional dyspnea • exertional dyspnea, often described as increased effort to breathe, heaviness, air hunger, or gasping, can be insidious • patient's ability to perform them has changed

42. Clinical presentation • Physical Findings • entirely normal physical examination – early • signs of active smoking, including an odor of smoke or nicotine staining of fingernails • prolonged expiratory phase and expiratory wheezing- more severe • signs of hyperinflation include a barrel chest and enlarged lung volumes

43. Laboratory Findings • hallmark of COPD is airflow obstruction • Pulmonary function testing shows airflow obstruction with a reduction in FEV1 and FEV1/FVC • lung volumes may increase

45. COPD Management • Goals: • Relieve symptoms • Prevent disease progression • Improve exercise tolerance • Improve health status • Prevent and treat complication • Prevent and treat exacerbations • Reduce mortality • Prevent or minimize side effects from treatment

46. COPD Management • In addition to spirometry, other test maybe considered for the assessment of stage 2 – 4 COPD • Bronchodilator reversibility testing • To rule out a diagnosis of asthma • Chest xray • Abg • Performed in patients with FEV1 <50% • Alpha 1 antitrypsin deficiency • Performed in patients of caucasian descent under 45 y.o. with a strong family hx of COPD

47. Treatment • SMOKING cessation • Bronchodilators • Anticholinergic agents • Beta agonists • Inhaled Glucocorticoids • Oral Glucocorticoids • Theophylline • Oxygen

48. Treatment • General Medical Care • Pulmonary Rehabilitation • Lung Volume Reduction Surgery • Lung Transplantation