ASTHMA

1. ASTHMA Victor Politi, M.D., FACP Medical Director, SVCMC School of Allied Health

2. What is Asthma? • Asthma is a chronic condition that occurs when the main air passages of the lungs, the bronchial tubes, become inflamed. • The muscles of the bronchial walls tighten and extra mucus is produced, causing the airways to narrow. • can lead to minor wheezing to severe difficulty in breathing. • In some cases, breathing may be so labored that an asthma attack becomes life-threatening

4. Definitions • Asthma • Reversible airway obstruction • Airway inflammation • Increased bronchial hyperresponsiveness • Status Asthmaticus • Severe airway obstruction developing over days-weeks

5. The Respiratory System

6. Pathophysiology • Hallmark of Asthma -Bronchial wall Hyperresponsiveness • Early Phase Asthma Reaction • Bronchoconstriction • Antigenic Stimulation of bronchial wall • Mast Cell Degranulation releases • Histamine • Chemotactics • Proteolytics • Heparin • Smooth Muscle Bronchoconstriction

7. Pathophysiology • Late Phase Asthma Reaction: Bronchial Inflammation • Inflammatory Cells Recruited • Neutrophils • Monocytes • Eosinophils • Release Cytokines, Vasoactives, Arachidonic acid • Epithelial and Endothelial Cell inflammation • Release of Interleukin 3-6, TNF, Interferon-gamma

10. Risk Factors • Family History • One parent with asthma: up to 25% risk for child • Two parents with asthma: up to 50% risk for child • Parental tobacco use • Associated aspirin or NSAID allergy • Classic Triad: • Asthma, Nasal polyps, Aspirin allergy • RSV Bronchiolitis history • Strongly associated with later development of asthma • Strenuous exercise in areas of high ozone (pollution)

11. Types of Asthma • Extrinsic Asthma (Allergic) • Intrinsic Asthma (Non-allergic) • Mixed Asthma (Extrinsic and Intrinsic) • Occupational Asthma • Drug Induced Asthma • Aspirin-induced Asthma • NSAID-induced Asthma • Exercise Induced Asthma • Cough Variant Asthma • Very common! (Especially in children)

12. Asthma Statistics • For reasons no one quite understands, the number of asthma cases has risen dramatically during the past decade, especially among children living in the inner city. • Approximately 14 million Americans have asthma, including more than 6 million children. • Asthma is the most common chronic illness of childhood. • Among young children, asthma is more common in boys than in girls. • After puberty asthma becomes more common in girls

13. Intrinsic Asthma Non-allergic asthma • Pathophysiology • Non-IgE, Non-allergic asthma • Precipitating Factors • Irritant exposure • (Air Pollution, Fumes, Perfumes, Household cleaning agents, Insecticides, paint, tobacco, cold air • Infection • URI, purulent rhinitis, acute sinusitis • GERD • Epidemiology • Much more common in adults than children • Onset age over 40 years old

14. Extrinsic Asthma Allergic Asthma • Pathophysiology • IgE mediated response to allergens • Immediate allergic reaction • Late-phase allergic reaction • Causes • Indoor allergens • House –Dust mites (most common extrinsic allergen) • Animal proteins (animal dander) • Mold spores • Cockroaches • Outdoor allergens • Pollens , mold spores • Epidemiology • Much more common in children than adults • Age Onset under 40 years old

15. Asthma Triggers

16. Asthma Triggers

17. Asthma Triggers

19. All Asthma attacks give a warning • Warning signs and symptoms for adults can include: • Increased shortness of breath or wheezing • Disturbed sleep caused by shortness of breath, coughing or wheezing • Chest tightness or pain • Increased need to use bronchodilators — medications that open up airways by relaxing the surrounding muscles • A fall in peak flow rates as measured by a peak flow meter

20. All Asthma attacks give a warning • Warning signs and symptoms for children may include • An audible whistling or wheezing when the child exhales • Coughing, especially if the cough is frequent and occurs in spasms • Waking at night with coughing or wheezing • Shortness of breath, which may or may not occur when the child exercises • A tight feeling in the child's chest

21. Asthma and Other Conditions • Differentiating between asthma and chronic obstructive pulmonary disease (COPD) such as emphysema and chronic bronchitis can be especially challenging. • Asthma and COPD each cause similar symptoms. • Not uncommon for older adults — especially longtime smokers — to have both conditions. • Various tests — including skin or blood tests for allergies, and spirometry — can help determine whether asthma is present.

22. What is cardiac asthma? • Cardiac asthma isn't actually asthma. • It refers to the wheezing that's caused by CHF • Excess fluid in the lungs (pulmonary edema) associated with heart failure causes signs and symptoms such as shortness of breath, coughing and wheezing, which mimic asthma

23. Exercise Induced Asthma • Exercise-induced asthma — or exercise-induced constriction of the bronchial tubes (bronchospasm) • a condition in which the airways narrow significantly during vigorous exercise. • Typical Symptoms • Cough, Wheezing, Shortness of breath, Chest tightness • Typically symptoms present about 10 minutes after stopping exercise

25. Exercise Induced Asthma • Exercise-induced wheezing or shortness of breath is typical for people who have chronic asthma. • But exercise-induced wheezing or shortness of breath can occur when sensitive airways constrict when exercising, especially when combined with cold air, low humidity or pollution.

26. Chronic Asthma or Exercise Induced Asthma • Basic difference between chronic asthma and exercise-induced asthma • People with exercise-induced asthma have symptoms only with physical activity. • People with chronic asthma often have exercise-induced wheezing or shortness of breath, but they may have asthma symptoms at other times as well.

27. Exercise Induced Asthma - Medications • The most common medications for exercise-induced asthma are bronchodilators, which are taken about 15 to 30 minutes before exercising • Medications Include: • Albuterol (Proventil, Ventolin) • Pirbuterol (Maxair) • Ipratropium and albuterol combination (Combivent)

28. What's the difference between asthma and COPD? • similar symptoms but very different • Asthma causes reversible lung inflammation, • COPD causes irreversible lung damage • It's important to distinguish between the two conditions because they're treated differently

29. What's the difference between asthma and COPD? • Smoking history. Asthma may occur in nonsmokers as well as in smokers. But COPD is usually associated with a long history of smoking

30. What's the difference between asthma and COPD? • Symptoms • Periodic wheezing and chest tightness, especially at night, is typical of asthma. • COPD is more likely to cause a daily morning cough that produces mucus. • In COPD, patients may develop a permanently expanded barrel chest because too much air is trapped in the lungs.

31. Cough Variant Asthma • Chronic cough – • Cough > 3 weeks • Nonproductive • Usually nocturnal – but can occur anytime • Occur any age group • PFTs –normal • Rule out other causes of chronic cough • TX • Similar to common forms of asthma

32. Asthma EvaluationDifferential Diagnosis • General • All that wheezes is not asthma!! • However most recurrent cough and wheeze is asthma • Upper airway disease • Allergic rhinitis • sinusitis • Large airway obstruction • Foreign body • Vocal cord dysfunction • Vascular rings of laryngeal webs • Laryngotracheomalacia • Tracheobronchial-stenosis • Enlarged lymph node or tumor

33. Asthma EvaluationDifferential Diagnosis • Small Airway obstruction • Viral Bronchiolitis • Bronchiolitis obliterans • Cystic Fibrosis • Bronchopulmonary dysplasia • Heart disease • Other Causes • Psychogenic cough • GERD • ACE inhibitors

34. Asthma EvaluationHistory • General: History is not always accurate • Confirm with PFTs every 3-6 month • Patient may underplay symptoms • 10% of patients do not recognize severe Symptoms of their asthma • Age of onset and asthma diagnosis • Past history of respiratory failure or intubation • Recognize cohorts at additional risk • Elderly • Pregnancy

35. Asthma EvaluationHistory • History of early life injury to airways • Bronchopulmonary Dysplasia • Parental smoking • Disease progression • Present management and response • Frequency of systemic corticosteroid use • History steroid-induced complications • Comorbid conditions • Chronic sinusitis • Assess in all asthma patients • Consider empiric treatment if refractory asthma

36. Asthma EvaluationHistory • Family History (any asthma, allergic rhinitis, etc.) • Social History • Home characteristics • Heating and cooling system • Wood burning stove • Humidifier • Carpeting over concrete • Smokers in home • Daycare and school situation impacting compliance

37. Asthma EvaluationSigns: Respiratory distress • Tachypnea • Dyspnea • Anxiety • Accessory Muscle Use • Intercostal muscle use • Sternocleidomastoid use • Scalenes Muscle use • Cyanosis in severe cases (lips) • Tachycardia

38. Asthma EvaluationRadiology: chest x-ray • Indications • Initial asthma diagnosis • Low yield in acute asthma exacerbations • Abnormal findings at presentation: 5% • Abnormal findings if no improvement in 12 hours: 34% • Status Asthmaticus or no acute asthma improvement • Excludes other diagnoses • CHF • Pneumonia • Excludes complications • Pneumothorax • Pneumomediastinum

39. Asthma EvaluationLabs • ABGs • Hypoxemia • Hypercarbia (or normal CO2) with decompensation • CBC • Eosinophilia may be present • Increased Levels of IgE may be present • Sputum Sample • May show casts of small airways • Thick mucoid sputum • Curschmann's spirals • Charcot-Leyden crystals

40. Asthma EvaluationOther Diagnostic Tests • PFT’s – Pulmonary Function Testing • Spirometry • Methacholine Challenge

41. What are PFT's? • Pulmonary function testing is one of the basic tools for evaluating a patient's respiratory status. • In patients with suspected pulmonary disease, it is often the first diagnostic test employed in the work up. • Pulmonary function tests (PFT's) are also used for pre-operative evaluation, managing patients with known pulmonary disease, and quantifying pulmonary disability

42. PFT- Spirometry • A versatile test of pulmonary physiology. • Reversibility of airways obstruction can be assessed with the use of bronchodilators. • After spirometry is completed, the patient is given an inhaled bronchodilator and the test is repeated. • The purpose of this is to assess whether a patient's pulmonary process is bronchodilator responsive by looking for improvement in the expired volumes and flow rates

43. PFT- Spirometry • spirometry can be used to detect the bronchial hyperreactivity that characterizes asthma. • By inhaling increasing concentrations of histamine or methacholine, patients with asthma will demonstrate symptoms and produce spirometric results consistent with airways obstruction at much lower threshold concentration than normal

44. PFT- Spirometry • Normal values vary depending on gender, race, age, and height. • It is therefore not possible to interpret PFT's without such information. • There is no single set of standard reference values, however, and "normal" varies with the reference value used in each laboratory

45. PFT- SpirometryDefinitions • FEV1 - forced expiratory volume 1 - the volume of air that is forcefully exhaled in one second. • FVC - forced vital capacity - the volume of air that can be maximally forcefully exhaled • FEV1/FVC - ratio of FEV1 to FVC, expressed as a percentage • FEF25 - 75 - forced expiratory flow - the average forced expiratory flow during the mid (25 - 75%) portion of the FVC • PEF - peak expiratory flow rate - the peak flow rate during expiration

46. PFT- Spirometry • In general, a > 12% increase in the FEV1 (an absolute improvement in FEV1 of at least 200 ml) or the FVC after inhaling a beta agonist is considered a significant response. • However, the lack of an acute bronchodilator effect during spirometry does not exclude a response to long term therapy

48. Mild Obstruction Flow Volume Normal Flow Volume Loop

49. Asthma Medications • Two general types of asthma medications • Anti-inflammatory • Corticosteroids reduce swelling & mucous in airways • Bronchodilators • Relax muscle bands around airways allowing more air to flow, also increases mucous movement

50. Quick Relief Medications • Short acting beta-agonists • (bronchodilators that are the drug of choice to relieve asthma attack and prevent exercise-induced asthma symptoms) • Anticholinergics • (bronchodilators used in addition to short-acting beta agonists when needed or as an alternative to these drugs when needed) • Systemic corticosteroids • (anti-inflammatory drug used in an emergency to get rapid control of the disease while initiating other treatments and to speed recovery)