Asthma
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Asthma is a chronic inflammatory airway disease characterized by periods of reversible bronchospasm. Common triggers include allergens, irritants, and environmental factors. Symptoms include wheezing, coughing, chest tightness, and shortness of breath. Diagnosis involves assessing symptoms, lung function tests, and response to treatment. Management involves long-term control medications like inhaled corticosteroids and bronchodilators, as well as quick-relief medications for exacerbations. Treatment is tailored based on asthma severity and level of control.
Asthma
- 1. Asthma Reactive Airway Disease Mr. Sanil Varghese Lecturer YNC YU
- 2. Definition of Asthma Chronic inflammatory disorder of the airways characterized by periods of reversible bronchospasm. Chronic inflammation is associated with airway hyper responsiveness that leads to recurrent episodes of wheezing, breathlessness, chest tightness, and coughing, particularly at night or in the early morning.
- 3. Asthma Triggers Allergens Dust mites, mold spores, animal dander, cockroaches, pollen, indoor and outdoor pollutants, irritants (smoke, perfumes, cleaning agents) Pharmacologic agents (ASA, beta-blockers) Physical triggers (exercise, cold air) Physiologic factors Stress, GERD, viral and bacterial URI, rhinitis
- 4. .
- 5. Factors that Exacerbate Asthma Allergens Respiratory infections Exercise and hyperventilation Weather changes Sulfur dioxide Food, additives, drugs © Global Initiative for Asthma
- 6. Factors that Influence Asthma Development and Expression Host Factors Genetic - Atopy - Airway hyperresponsiveness Gender Obesity Environmental Factors Indoor allergens Outdoor allergens Occupational sensitizers Tobacco smoke Air Pollution Respiratory Infections Diet © Global Initiative for Asthma
- 7. Asthma Inflammation: Cells and Mediators Source: Peter J. Barnes, MD
- 8. Mechanisms: Asthma Inflammation Source: Peter J. Barnes, MD
- 9. Asthma Inflammation: Cells and Mediators Source: Peter J. Barnes, MD
- 10. Figure 9-10. Bronchospasm clinical scenario (e.g., asthma).
- 11. Figure 9-11. Excessive bronchial secretions clinical scenario.
- 12. Diagnostic Testing Peak expiratory flow (PEF) Inexpensive Patients can use at home
- 13. Diagnostic Testing Spirometry Recommended to do spirometry pre- and post- use of an albuterol MDI to establish reversibility of airflow obstruction > 12% reversibility or an increase in FEV1 of 200cc is considered significant Obstructive pattern: reduced FEV1/FVC ratio Restrictive pattern: reduced FVC with a normal FEV1/FVC ratio
- 14. Diagnostic Testing Spirometry National Asthma Education and Prevention Program (NAEPP) recommends spirometry: For initial assessment Evaluation of response to treatment Assessment of airway function at least every 1-2 years
- 15. Diagnostic Testing Methacholine challenge Most common bronchoprovocative test in US Patients breathe in increasing amounts of methacholine and perform spirometry after each dose Increased airway hyperresponsiveness is established with a 20% or more decrease in FEV1 from baseline at a concentration < 8mg/dl May miss some cases of exercise-induced asthma
- 16. Diagnostic testing Diagnostic trial of anti-inflammatory medication (preferably corticosteroids) or an inhaled bronchodilator Especially helpful in very young children unable to cooperate with other diagnostic testing There is no one single test or measure that can definitively be used to diagnose asthma in every patient
- 17. Clinical Data Obtained at the Patient’s Bedside Vital signs Increased respiratory rate Increased heart rate, cardiac output, blood pressure
- 18. Clinical Data Obtained at the Patient’s Bedside Use of accessory muscles of inspiration Use of accessory muscles of expiration Pursed-lip breathing Substernal intercostal retractions Increased anteroposterior chest diameter (barrel chest) Cyanosis Cough and sputum production
- 19. Clinical Data Obtained at the Patient’s Bedside Pulsus paradoxus Decreased blood pressure during inspiration Increased blood pressure during expiration
- 20. Clinical Data Obtained at the Patient’s Bedside Chest assessment findings Expiratory prolongation Decreased tactile and vocal fremitus Hyperresonant percussion Diminished breath sounds Diminished heart sounds Wheezing and rhonchi
- 21. Figure 2-12. Percussion becomes more hyperresonant with alveolar hyperinflation.
- 22. Figure 2-17. As air trapping and alveolar hyperinflation develop in obstructive lung diseases, breath sounds progressively diminish.
- 23. Pulmonary Function Study: Expiratory Maneuver Findings FVC FEVT ↓ ↓ PEFR MVV ↓ ↓ FEF25%-75% FEF200-1200 ↓ FEF50% ↓ ↓ FEV1% ↓
- 24. Pulmonary Function Study: Lung Volume and Capacity Findings VT RV FRC N or ↑ ↑ ↑ VC IC ↓ ERV N or ↓ TLC N or ↑ RV/TLC ratio N or ↓ ↑
- 25. Arterial Blood Gases Mild to Moderate Asthma Episode Acute alveolar hyperventilation with hypoxemia pH PaCO2 ↑ ↓ HCO3↓ (Slightly) PaO2 ↓
- 26. Arterial Blood Gases Severe Asthmatic Episode (Status Asthmaticus) Acute ventilatory failure with hypoxemia pH ↓ PaCO2 HCO3↓ PaO2 ↓ (Significantly) ↓
- 27. Abnormal Laboratory Tests and Procedures Abnormal laboratory tests and procedures Sputum examination Eosinophils Charcot-Leyden crystals (see next slide) Casts of mucus from small airways called Kirschman spirals IgE level (elevated in extrinsic asthma)
- 28. Charcot-Leyden Crystals Needle shaped crystals Represents breakdown products of eosinophils
- 29. Radiologic Findings Chest radiograph Increased anteroposterior diameter Translucent (dark) lung fields Depressed or flattened diaphragm
- 30. Figure 13-4. Chest X-ray of a 2-year-old patient during an acute asthma attack.
- 31. Asthma Classification Based on Severity—Excerpts Disease Step 4: Step 3: Step 2: Step 1: Symptoms Continual symptoms Daily symptoms Symptoms > than twice weekly Symptoms < than twice weekly From McCance KL, Huether SE: Pathophysiology: The biologic basis for disease in adults and children, ed 4, St. Louis, 2002, Mosby.
- 32. Asthma Zone Management System —Excerpts Green zone Yellow zone 80% to 100% of personal best PEFR 50% to 80% of personal best PEFR Red zone <50% of personal best PEFR
- 33. Pharmacologic Therapy Long-term control medications Corticosteroids inhaled form systemic steroids used to gain prompt control of disease when initiating inhaled treatment Cromolyn sodium or Nedocromil mild-to-moderate anti-inflammatory medications (may be used initially in children) preventive treatment prior to exercise or unavoidable exposure to known allergens
- 34. Long-term control medications Long-acting beta2-agonists used concomitantly with anti-inflammatory meds for long-term symptom control especially nocturnal symptoms prevents exercise-induced bronchospasm Methylxanthines sustained-release theophylline used as adjuvant to inhaled steroids for prevention of nocturnal symptoms
- 35. Long-term control medications Leukotriene modifiers zafirlukast - leukotriene receptor antagonist zileuton - 5-lipoxygenase inhibitor is alternative therapy to low doses of inhaled steroids/nedocromil/cromolyn alternative tx to low dose inhaled steroids/cromolyn/nedocromil recommended for >12yrs with mild persistent asthma. Further study needed
- 36. Quick relief medications Short acting beta2-agonists - relief of acute symptoms Anticholinergics - may provide additive benefit to beta2 drugs in severe exacerbation. May be alternative to beta2-agonists Systemic steroids - moderate-to-severe persistent asthma in acute exacerbations or to prevent recurrence of exacerbations
- 37. Treatment/Long Term Control Corticosteroids Most potent and effective Reduction in symptoms, improvement in PEF and spirometry, diminished airway hyperresponsiveness, prevention of exacerbations, possible prevention of airway wall remodeling Suppresses: cytosine production, airway eosinophilic recruitment, chemical mediators
- 38. Corticosteroids Dose dependent on product and delivery device 2 X/day use is common in moderate-to-severe persistent asthma 1 or 2 X/day may be used in mild persistent asthma
- 39. Cromolyn & nedocromil Have distinctive properties Similar anti-inflammatory reactions blocks Cl - channels modulate mast cell mediator release modulate eosinophilic recruitment inhibits early and late asthmatic response to antigen challenge
- 40. Cromolyn & nedocromil Similar anti-inflammatory reactions inhibits bronchospasm (exercise, cold dry air, bradykinin aerosol) nedocromil more potent in inhibiting bronchospasm in the above situations Both reduce asthma symptoms improve PF reduce need for short acting beta2 agonists
- 41. Long-acting beta-2 agonists Relax airway smooth muscle Duration of action >12 hrs Not used in acute exacerbations Adjunct to anti-inflammatory tx for long-term symptom control especially nocturnal symptoms
- 42. Methylxanthines Provides mild-moderate bronchodilation Low dose has mild anti-inflammatory action Sustained release form used as alternative but not preferred to long-acting beta2 agonists to control nocturnal symptoms Use may be necessary because of cost or patient compliance
- 43. Leukotriene modifiers Leukotrienes are potent biochemical mediators released from mast cells, eosinophils, and basophils that: contract bronchial smooth muscle increase vascular permeability increase mucus secretions attract & activate inflammatory cells in airways
- 44. Leukotriene modifiers Zafirlukast & zileuton (oral tabs) improves lung fx and diminishes symptoms & need for short-acting beta2 agonists Studies in mild-moderate asthma showing modest improvements Alternative to low-dose inhaled steroids for pts. with mild persistent asthma Further study in of other groups needed
- 45. Leukotriene modifiers Zafirlukast - leuktriene receptor antagonist attenuates late response to inhaled allergen and postallergen induced bronchospasm modest improvement in FEV (11% > placebo) 1 improved symptoms reduced albuterol use Warning - increases warfarin half-life and PT & PTT must be monitored with dose adjustment when indicated
- 46. Leukotriene modifiers Zileuton - 5-lipoxygenase inhibitor provides immediate & sustained improvement in FEV1 (mean 15% > placebo) in mild-to-moderate asthma moderate asthmatics had fewer exacerbations requiring oral steroids attenuates bronchospasm from exercise & from aspirin in sensitive people inhibits metabolism of theophylline, warfarin, terfenadine and must be monitored
- 47. Asthma Treatment/Quick Relief Short-acting beta2 agonists Relax airway smooth muscle and increase in airflow in <30 minutes Drug of choice for treating symptoms and exacerbations and EIB Use of >1 canister/mo indicates inadequate control and indicates need to intensify antiinflammatory tx Regularly scheduled use NOT recommended
- 48. Anticholinergics Cholinergic innervation important in regulation of airway smooth muscle tone Ipratropium bromide (quaternary derivative of atropine without its’ side effects) Additive benefit with inhaled beta 2-agonists in severe asthma exacerbations Effectiveness in long-term management not demonstrated
- 49. Intermittent Asthma Step 1 Short-acting inhaled beta 2 agonists PRN IF NEEDED >2 X/wk PATIENT SHOULD BE MOVED TO THE NEXT STEP OF CARE (exception is EIB or viral infections) Viral infections mild symptoms - beta 2 agonist Q 4-6 hr moderate-to-severe symptoms - short course of systemic steroids recommended plus above
- 50. Persistent Asthma Mild, moderate or severe Daily long-term control recommended Mild persistent asthma (step 2 care) Daily anti-inflammatory meds - inhaled steroids (low dose) or cromolyn or nedocromil Sustained release theophylline alternative but not preferred
- 51. Mild persistent asthma (step 2 care) Zafirlukast or zileuton considered in pts. >12 yrs Quick relief medications must be available short-acting beta 2 agonists intensity depends upon severity of exacerbation
- 52. Moderate persistent asthma (step 3 care) Increase inhaled steroids to medium dose OR Add long-acting bronchodilator to a low-medium dose of inhaled steroids OR Increase to medium dose steroid then lower dose & add nedocromil (+/-)
- 53. Moderate persistent asthma (if not adequately controlled) Increase to high dose inhaled steroids & add longacting bronchodilator (serevent or theophylline)
- 54. Severe persistent asthma (step 4) If not controlled on high dose of inhaled steroids and long-acting bronchodilator ADD oral systemic steroids on a regularly scheduled, longterm basis use lowest dose monitor closely attempt to reduce or take off when control established
- 55. Emergency Department Treatment Start treatment when asthma exacerbation recognized While treatment is being given: Take a more detailed history Complete physical examination Perform laboratory studies PEF on presentation, after initial tx. and at frequent intervals)
- 56. Perform laboratory studies FEV1 or PEF <50% pred. then assess oxygenation by pulse oximetry Lab studies will vary with situation (CBC, electrolytes, serum theophylline level. CXR, ECG). These lab studies are NOT routinely recommended
- 57. Treatment: O2 (Sa O2 90-95), inhaled short-acting bronchodilator for all pts. (3 tx Q 20 min, continuous therapy an option) Consider anti-cholinergics oral systemic corticosteroids (unresponsive to initial beta2 agonist therapy, moderate-to-severe asthma, people who are on steroids) systemic steroids administered when admitted methylxanthines are not recommended
- 58. Treatment: Aggressive hydration NOT recommended for older children and adults (may be necessary with infants and sm. children) Antibiotics NOT recommended unless infection present (fever, purulent sputum) CPT NOT recommended Mucolytics NOT recommended Sedation NOT recommended
- 59. Long-Term, Control Medications Decrease the inflammation/swelling Advair
- 60. Quick R elief Medications Loosens your muscles & stops the wheezing Albuterol for Nebulizer
- 61. Spacers
- 62. Without Spacer ©1998, Respironics Inc. With Spacer
- 63. Why Control Asthma? •Mild intermittent •Mild persistent •Moderate persistent •Severe persistent
Editor's Notes
- #60: These medicines reduce inflammation and mucus production. They do nothing for bronchospasm. Do not use them for quick relief of symptoms. Take these medications EVERYDAY even if you feel OK. Advair is a new combination medicine of Flovent and Serevent. Flovent is a corticosteroid and Serevent is a long-acting bronchodilator. Neither medicine is for quick relief of symptoms.
- #61: These medications relax the muscles, but they do nothing for inflammation and swelling. All the pictured medicines do the same thing. Keeping various of these meds in different locations is OK, but they shouldn’t all be used to treat a flare-up at the same time. Albuterol, Ventolin, Proventil all are different brand names of the same medicine: Albuterol. Maxair inhaler is pirbuterol(similar to Albuterol. Works the same as Albuterol) This is a breath-actuated inhaler so it’s good for kids who won’t carry spacers. However, insurance doesn’t cover it so we don’t see it much. Xopenex is a brand that contains lev-albuterol (no isomer - works the same as Albuterol, but they say it doesn’t cause side effects). This is only available as a nebulizer treatment.
- #62: Spacers come in many shapes and sizes. The only bad spacer is the one that isn’t used. All people with asthma, adults and children, should be using spacers.
- #63: These pictures show how medication is deposited in the lungs when using or not using a spacer. An MDI discharges medicine at 45 miles per hour. Spacers slow the medicine down to facilitate inhalation. Without a spacer much of the medicine falls on the mouth and the back of the throat. Then it is swallowed to the stomach and absorbed into the blood stream. When Albuterol gets into the blood stream, it can cause jitters. (A placebo inhaler can be passed around so that the audience can feel how hard it is to inhale medicine from an MDI without a spacer.) When using a spacer, most of the medicine gets into the lungs. Very little reaches the blood stream, so side effects are minimized.
- #64: This picture can be used to describe asthma categories: Mild intermittent Mild persistent Moderate persistent Severe persistent All categories have the same risk of death. People with mild asthma often think “it’s mild, so I don’t have to worry about it”. These are the same people who have the most severe asthma attacks. Use this picture to describe what happens if you stop taking long-term control medications. If you take quick relief medication at the onion ring stage, your muscles will relax and your airways will go back to normal. If you take a quick relief med at the bagel stage, the muscles will relax, but your airway will only go back to bagel…..This is how people get used to compromised breathing. Take control medications everyday, even if you feel OK.