2. Obstructive Pulmonary Diseases Asthma, Chronic Bronchitis, Emphysema (Lewis, et al, 8 th ed.) Part 1

3. Obstructive Pulmonary Diseases Increased resistance to airflow as a result of airway obstruction or narrowing Obstruction caused by: Secretions, edema, swelling of inner lumen, bronchospasm, destruction of lung tissue Asthma – usually reversible Emphysema and chronic bronchitis – irreversible Cystic fibrosis – genetic Bronchiectasis - irreversible

4. Asthma Chronic inflammatory disorder Causes recurrent episodes: Wheezing, breathlessness, chest tightness, cough 3700 deaths per year due to asthma

5. Asthma Triggers Genetics Immune Response Allergens: IgE response to dust, pollen, animal danders etc. Mast cell release histamine and other inflammatory mediators Exercise Induced (EIA) Treat before exercise Air pollution/Occupational factors Respiratory Infections: viral/ not bacterial Chronic Sinusitis Allergic rhinitis Inflammation Drugs and Food Additives Asthma triad: ASA, nasal polyps, asthma Sensitive to salicylates Beta-blockers, ACE inhibitors GERD Reflux triggers bronchoconstriction Stress

6. Pathophysiology of Asthma Acute airway inflammation Hyper-responsiveness of airway Causes bronchoconstriction and bronchospasm Increased mucus production

7. Pathophysiology of Asthma Early-phase response - Fig. 29-2 Within 30-60 min. of exposure 1.Mast cell degranulation in response to allergen 2. IgE is activated by allergen 3. Mast cell membrane is disrupted 4. Mast cell releases: histamine, bradykinin, leukotrienes, prostaglandins, platelet- activating factor, chemotactic factors

8. Pathophysiology of Asthma Late-phase response 4-10 hours after exposure, persists for 24 hours or more. 30-50% of patients. Inflammation Eosinophils and neutrophils invade airway, can further stimulate release of histamine and other mediators Airway diameter is reduced by inflammation, constriction of bronchial smooth muscle and excess mucus

9. Symptoms of Asthma Wheezing unreliable Starts as expiratory, then can be inspiratory and expiratory Then can disappear-BAD Chest tightness Cough especially at night Dyspnea Exposure to allergen Prolonged expiration Onset can be gradual or sudden Air hunger Accessory muscles of respiration

10. Physical Findings in Asthma Hypoxemia - < 90% SaO 2, PaO 2 < 80 mmHg Restlessness Anxiety  HR, BP, RR – can be up to 30 b/min Hyperresonance with percussion – air trapping Inspiratory or expiratory wheezing Prolonged expiratory phase Absent breath sounds

11. Complications of Asthma Rib fractures Pneumothorax Atelectasis Pneumonia Status asthmaticus: Severe, life-threatening Refractory to treatment Hypoxemia, hypocapnia, then hypercapnia as fatigue results in CO 2 retention

12. Diagnostic Studies Identification of triggers – allergy testing may help Pulmonary function tests - PFT’s  forced expiratory volume in 1 second (FEV 1 ) Often normalize after treatment CXR – hyperinflation with acute attack Peak Flow Monitoring – estimates FEV 1

13. Collaborative Care Mild or persistent asthma Identification and removal/avoidance of triggers Desensitization Patient and family education Smoking cessation Peak flow monitoring Medication management Proper use

14. Collaborative Care Stepwise Approach - Table 29-4, p. 594 Step 1 - Intermittent Step 2 – 6 Persistent Drug Therapy – Table 29-7, p. 598

16. Asthma Medications Corticosteroids Anti-inflammatory (po, IV, inhaled) Reduce bronchial hyper-responsiveness, block late-phase response hydrocortisone (Solu-cortef), methylprednisolone (Medrol or Solu-medrol ), beclomethasone (Vanceril), fluticasone (Flovent)…many others Use spacer for inhaled steroids! If not available must rinse mouth and spit out.

17. Asthma Medications Leukotriene modifiers - po Block action and interfere with synthesis of leukotrienes (potent bronchoconstictors), one of the chemicals of inflammation zafirlukast (Accolate), montelukast (Singulair)

18. Asthma Medications Bronchodilators B-adrenergic agonist drugs (B 2 agonists) Short-acting: albuterol (Proventil, Ventolin), metaproterenol (Alupent) – onset = quick, duration = short Onset minutes, duration 4-8 hrs Overusage causes tremors, anxiety, tachycardia, palpitations, nausea These symptoms are from stimulation of the B 1 receptors found primarily in cardiovascular system Long-acting Advair Diskus – combination dry powder inhaler (DPI) salmeterol + fluticasone, salmeterol (Serevent) Onset = slow, duration = 12 hours

19. Asthma Medications Mast cell stabilizer, MDI Antiinflammatory of choice for kids EIA cromolyn (Intal) and nedocromil (Tilade)

20. Asthma Medications Methylxanthines – theophylline (Theo-Dur, Slo-bid, etc. ) IV or po Relaxation of bronchial smooth muscle, improved diaphragm function Side effects: tachycardia, BP changes, arrhythmias, nausea, nervousness Many drug-drug interactions: cimetidine, quinolones (ciprofloxacin), macrolides (erythromycin) Take after meals with plenty of water

21. Asthma Medications Anticholinergics – ipratropium(Atrovent) Inhibit brochoconstriction related to parasympathetic nervous system, airway diameter Onset 1 hour, duration 4-6 hours May be given in combination with B 2 agonists (Combivent)

22. Acute Asthma Attack!! FEV 1 assessed, compare to baseline if able Pulse oximetry Oxygen therapy immediately Short-acting B 2 agonist via MDI or nebulizer every 20 minutes Corticosteroids: po or IV based on severity of attack Monitor until wheezing is resolved and peak flow is normalized

23. Patient Education R/T Drug Therapy Name, dosage, route, use of MDI, schedule Purpose Side effects Consequences of improper use Refilling medications Discourage use of OTC drugs Too short acting, ephedrine stim. CNS and CV Emergency procedure (table 29- 13) Peak flow reading Quick acting bronchodilator 2 puffs every 20 minutes for 1 hour Call MD if resolving Call 911 if not