1. Copyright © 2006 by Mosby, Inc. Slide 1 Chapter 13 Asthma Figure 13-1. Asthma. DMC, Degranulation of mast cell; SMC, smooth muscle constriction; MA, mucus accumulation; MP, mucus plug; HALV, hyperinflation of alveoli.

2. Copyright © 2006 by Mosby, Inc. Slide 2 Anatomic Alterations of the Lungs  Smooth muscle constriction of bronchial airways (bronchospasm)  Excessive production of thick, whitish, tenacious bronchial secretions  Hyperinflation of alveoli (air-trapping)  Mucus plugging and, in severe cases, atelectasis

3. Copyright © 2006 by Mosby, Inc. Slide 3 Etiology  Extrinsic asthma  Allergic or atopic asthma  Intrinsic asthma  Nonallergic or nonatopic asthma

4. Copyright © 2006 by Mosby, Inc. Slide 4 Figure 13-2. The immunologic mechanisms in asthma.

5. Copyright © 2006 by Mosby, Inc. Slide 5 Intrinsic Asthma (Nonallergic or Nonatopic Asthma)  Infections  Exercise and cold air  Industrial pollutants or occupational exposure  Drugs, food additives, and food preservatives  Gastroesophageal reflux  Sleep (nocturnal asthma)  Emotional stress  Premenstrual asthma

6. Copyright © 2006 by Mosby, Inc. Slide 6 Figure 13-3. Factors triggering intrinsic asthma.

7. Copyright © 2006 by Mosby, Inc. Slide 7 Additional Risk Factors  Residence in a large urban area, especially the inner city  Exposure to secondhand smoke  A parent who has asthma  Respiratory infections in childhood  Low birth weight  Obesity

8. Copyright © 2006 by Mosby, Inc. Slide 8 Overview of the Cardiopulmonary Clinical Manifestations Associated with ASTHMA The following clinical manifestations result from the pathophysiologic mechanisms caused (or activated) by Bronchospasm (see Figure 9-10) and Excessive Bronchial Secretions (see Figure 9-11)—the major anatomic alterations of the lungs associated with asthma (see Figure 13-1).

9. Copyright © 2006 by Mosby, Inc. Slide 9 Figure 9-10. Bronchospasm clinical scenario (e.g., asthma).

10. Copyright © 2006 by Mosby, Inc. Slide 10 Figure 9-11. Excessive bronchial secretions clinical scenario.

11. Copyright © 2006 by Mosby, Inc. Slide 11 Vital signs  Increased respiratory rate  Increased heart rate, cardiac output, blood pressure Clinical Data Obtained at the Patient’s Bedside

12. Copyright © 2006 by Mosby, Inc. Slide 12  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 Clinical Data Obtained at the Patient’s Bedside

13. Copyright © 2006 by Mosby, Inc. Slide 13 Pulsus paradoxus  Decreased blood pressure during inspiration  Increased blood pressure during expiration Clinical Data Obtained at the Patient’s Bedside

14. Copyright © 2006 by Mosby, Inc. Slide 14 Chest assessment findings  Expiratory prolongation  Decreased tactile and vocal fremitus  Hyperresonant percussion  Diminished breath sounds  Diminished heart sounds  Wheezing and rhonchi Clinical Data Obtained at the Patient’s Bedside

15. Copyright © 2006 by Mosby, Inc. Slide 15 Figure 2-12. Percussion becomes more hyperresonant with alveolar hyperinflation.

16. Copyright © 2006 by Mosby, Inc. Slide 16 Figure 2-17. As air trapping and alveolar hyperinflation develop in obstructive lung diseases, breath sounds progressively diminish.

17. Copyright © 2006 by Mosby, Inc. Slide 17 Clinical Data Obtained from Laboratory Tests and Special Procedures

18. Copyright © 2006 by Mosby, Inc. Slide 18 Pulmonary Function Study: Expiratory Maneuver Findings FVC FEV T FEF 25%-75% FEF 200-1200 FVC FEV T FEF 25%-75% FEF 200-1200         PEFR MVV FEF 50% FEV 1% PEFR MVV FEF 50% FEV 1%        

19. Copyright © 2006 by Mosby, Inc. Slide 19 Pulmonary Function Study: Lung Volume and Capacity Findings V T RV FRC TLC V T RV FRC TLC N or    N or  N or    N or  VC IC ERV RV/TLC ratio  N or  N or   VC IC ERV RV/TLC ratio  N or  N or  

20. Copyright © 2006 by Mosby, Inc. Slide 20 Arterial Blood Gases Mild to Moderate Asthma Episode  Acute alveolar hyperventilation with hypoxemia pH PaCO 2 HCO 3 - PaO 2    (Slightly) 

21. Copyright © 2006 by Mosby, Inc. Slide 21 Time and Progression of Disease 100 50 30 80 0 0 Pa CO 2 10 20 40 Alveolar Hyperventilation 60 70 90 Point at which PaO 2 declines enough to stimulate peripheral oxygen receptors Pa O 2 Disease Onset Pa O 2 or Pa CO 2 Figure 4-2. Pa O 2 and Pa CO 2 trends during acute alveolar hyperventilation.

22. Copyright © 2006 by Mosby, Inc. Slide 22 Arterial Blood Gases Severe Asthmatic Episode (Status Asthmaticus)  Acute ventilatory failure with hypoxemia pH PaCO 2 HCO 3 - PaO 2    (Significantly) 

23. Copyright © 2006 by Mosby, Inc. Slide 23 Time and Progression of Disease 100 50 30 80 0 Pa O 2 10 20 40 Alveolar Hyperventilation 60 70 90 Point at which PaO 2 declines enough to stimulate peripheral oxygen receptors Pa CO 2 Acute Ventilatory Failure Disease Onset Point at which disease becomes severe and patient begins to become fatigued Pa 0 2 or Pa C0 2 Figure 4-7. PaO 2 and PaCO 2 trends during acute ventilatory failure.

24. Copyright © 2006 by Mosby, Inc. Slide 24 Oxygenation Indices Q S /Q T D O 2 V O 2 C(a-v) O 2   Normal Normal   Normal Normal O 2 ER Sv O 2   O 2 ER Sv O 2  

25. Copyright © 2006 by Mosby, Inc. Slide 25 Abnormal Laboratory Tests and Procedures  Abnormal laboratory tests and procedures  Sputum examination Eosinophils Eosinophils Charcot-Leyden crystals (see next slide) Charcot-Leyden crystals (see next slide) Casts of mucus from small airways Casts of mucus from small airways  called Kirschman spirals IgE level (elevated in extrinsic asthma) IgE level (elevated in extrinsic asthma)

26. Copyright © 2006 by Mosby, Inc. Slide 26 Charcot-Leyden Crystals Needle shaped crystals - Represents breakdown products of eosinophils

27. Copyright © 2006 by Mosby, Inc. Slide 27 Radiologic Findings Chest radiograph  Increased anteroposterior diameter  Translucent (dark) lung fields  Depressed or flattened diaphragm

28. Copyright © 2006 by Mosby, Inc. Slide 28 Figure 13-4. Chest X-ray of a 2-year-old patient during an acute asthma attack.

29. Copyright © 2006 by Mosby, Inc. Slide 29 Table 13-1. Asthma Classification Based on Severity—Excerpts Disease Symptoms Step 4:Continual symptoms Step 4:Continual symptoms Step 3:Daily symptoms Step 3:Daily symptoms Step 2:Symptoms > than twice weekly Step 2:Symptoms > than twice weekly Step 1:Symptoms < than twice weekly Step 1: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.

30. Copyright © 2006 by Mosby, Inc. Slide 30 Table 13-2. Asthma Zone Management System—Excerpts  Green zone  80% to 100% of personal best PEFR  Yellow zone  50% to 80% of personal best PEFR  Red zone  <50% of personal best PEFR

31. Copyright © 2006 by Mosby, Inc. Slide 31 General Management of Asthma  Environmental control  Respiratory care treatment protocols  Oxygen therapy protocol  Bronchial hygiene therapy protocol  Aerosolized medication protocol  Mechanical ventilation protocol  Medications commonly prescribed  Xanthines  Corticosteroids  Anti-inflammatory agents  Leukotriene inhibitors

32. Copyright © 2006 by Mosby, Inc. Slide 32 General Management of Asthma  Monitoring  Arterial blood gas measurements  Pulse oximetry  Serial PFTs PEFR PEFR FEV 1 FEV 1  Vital signs  Chest radiographs

33. Copyright © 2006 by Mosby, Inc. Slide 33 General Management of Asthma  Patient compliance  Asthma-symptom/medication-use diaries  Serum theophylline levels  Carboxyhemoglobin determinations  Total (circulating) eosinophil counts  No-show rates at physician offices  Rate of medication use  Frequency of emergency department visits and hospitalizations  Number of red zone days per months (see Table 13-2)

34. Copyright © 2006 by Mosby, Inc. Slide 34 Classroom Discussion Case Study: Asthma