Asthma

1. Asthma

2. AsthmaDefinition • Reactive airway disease • Chronic inflammatory lung disease Inflammation causes varying degrees of obstruction in the airways • Asthma is reversible in early stages

3. Triggers of Asthma • Allergens • Exercise • Respiratory Infections • Nose and Sinus problems • Drugs and Food Additives • GERD • Emotional Stress

4. Early and Late Phases of Responses of Asthma Fig. 28-1

5. AsthmaPathophysiology • Bronchospasm • Airway inflammation

6. AsthmaPathophysiology Early-Phase Response • Peaks 30-60 minutes post exposure, subsides 30-90 minutes later • Characterized primarily by bronchospasm • Increased mucous secretion, edema formation, and increased amounts of tenacious sputum • Patient experiences wheezing, cough, chest tightness, and dyspnea

7. AsthmaPathophysiology Late-Phase Response • Characterized primarily by inflammation • Histamine and other mediators set up a self-sustaining cycle increasing airway reactivity causing hyperresponsiveness to allergens and other stimuli • Increased airway resistance leads to air trapping in alveoli and hyperinflation of the lungs • If airway inflammation is not treated or does not resolve, may lead to irreversible lung damage

8. Factors Causing Airway Obstruction in Asthma Fig. 28-3

9. Summary of Pathophysiologic Features • Reduction in airway diameter • Increase in airway resistance r/t • Mucosal inflammation • Constriction of smooth muscle • Excess mucus production

10. AsthmaClinical Manifestations • Unpredictable and variable • Recurrent episodes of wheezing, breathlessness, cough, and tight chest

11. AsthmaClinical Manifestations • Expiration may be prolonged from a inspiration-expiration ratio of 1:2 to 1:3 or 1:4 • Between attacks may be asymptomatic with normal or near-normal lung function

12. AsthmaClinical Manifestations • Wheezing is an unreliable sign to gauge severity of attack • Severe attacks can have no audible wheezing due to reduction in airflow • “Silent chest” is ominous sign of impending respiratory failure

13. AsthmaClinical Manifestations Difficulty with air movement can create a feeling of suffocation • Patient may feel increasingly anxious • Mobilizing secretions may become difficult

14. AsthmaClinical Manifestations Examination of the patient during an acute attack usually reveals signs of hypoxemia • Restlessness • Increased anxiety • Inappropriate behavior • Increased pulse and blood pressure • Pulsus paradoxus(drop in systolic BP during inspiratory cycle >10)

15. AsthmaComplications Status asthmaticus • Severe, life-threatening attack refractory to usual treatment where patient poses risk for respiratory failure

16. AsthmaDiagnostic Studies • Detailed history and physical exam • Pulmonary function tests • Peak flow monitoring • Chest x-ray • ABGs

17. AsthmaDiagnostic Studies • Oximetry • Allergy testing • Blood levels of eosinophils • Sputum culture and sensitivity

18. AsthmaCollaborative Care • Education • Start at time of diagnosis • Integrated into every step of clinical care • Self-management • Tailored to needs of patient • Emphasis on evaluating outcome in terms of patient’s perceptions of improvement

19. AsthmaCollaborative Care Acute Asthma Episode • O2 therapy should be started and monitored with pulse oximetry or ABGs in severe cases • Inhaled -adrenergic agonists by metered dose using a spacer or nebulizer • Corticosteroids indicated if initial response is insufficient

20. AsthmaCollaborative Care Acute Asthma Episode Therapy should continue until patient • is breathing comfortably • wheezing has disappeared • pulmonary function study results are near baseline values

21. AsthmaCollaborative Care Status asthmaticus • Most therapeutic measures are the same as for acute • Increased frequency & dose of bronchodilators • Continuous -adrenergic agonist nebulizer therapy may be given

22. AsthmaCollaborative Care Status asthmaticus • IV corticosteroids • Continuous monitoring • Supplemental O2 to achieve values of 90% • IV fluids are given due to insensible loss of fluids • Mechanical ventilation is required if there is no response to treatment

23. AsthmaDrug Therapy • Long-term control medications • Achieve and maintain control of persistent asthma • Quick-relief medications • Treat symptoms of exacerbations

24. AsthmaDrug Therapy • Bronchodilators • -adrenergic agonists (e.g., albuterol, salbutamol[Ventolin]) • Acts in minutes, lasts 4 to 8 hours • Short-term relief of bronchoconstriction • Treatment of choice in acute exacerbations

25. AsthmaDrug Therapy • Bronchodilators • Useful in preventing bronchospasm precipitated by exercise and other stimuli • Overuse may cause rebound bronchospasm • Too frequent use indicates poor asthma control and may mask severity

26. AsthmaDrug Therapy • Bronchodilators (longer acting) • 8 – 12 or 24 hr; useful for nocturnal asthma • Avoid contact with tongue to decrease side effects • Can be used in combination therapy with inhaled corticosteroid

27. AsthmaDrug Therapy Antiinflammatory drugs • Corticosteroids (e.g., beclomethasone, budesonide) • Suppress inflammatory response • Inhaled form is used in long-term control • Systemic form to control exacerbations and manage persistent asthma

28. AsthmaDrug Therapy Antiinflammatory drugs • Corticosteroids • Do not block immediate response to allergens, irritants, or exercise • Do block late-phase response to subsequent bronchial hyperresponsiveness • Inhibit release of mediators from macrophages and eosinophils

29. AsthmaDrug Therapy Anti-inflammatory drugs • Mast cell stabilizers (e.g., cromolyn, nedocromil) • Inhibit release of histamine • Inhibit late-phase response • Long-term administration can prevent and reduce bronchial hyper-reactivity • Effective in exercise-induced asthma when used 10 to 20 minutes before exercise

30. AsthmaDrug Therapy • Leukotriene modifiers (e.g. Singulair) • Leukotriene – potent bronchco-constrictors and may cause airway edema and inflammation • Have broncho-dilator and anti-inflammatory effects

31. AsthmaPatient Teaching Related to DrugTherapy Correct administration of drugs is a major factor in determining success in asthma management • Some persons may have difficulty using an MDI and therefore should use a spacer or nebulizer • DPI (dry powder inhaler) requires less manual dexterity and coordination

32. AsthmaPatient Teaching Related to DrugTherapy • Inhalers should be cleaned by removing dust cap and rinsing with warm water • -adrenergic agonists should be taken first if taking in conjunction with corticosteroids

33. Nursing ManagementNursing Diagnoses • Ineffective airway clearance • Anxiety • Ineffective therapeutic regimen management

34. Nursing ManagementPlanning • Normal or near-normal pulmonary function • Normal activity levels • No recurrent exacerbations of asthma or decreased incidence of asthma attacks • Adequate knowledge to participate in and carry out management

35. Nursing ManagementHealth Promotion • Teach patient to identify and avoid known triggers • Use dust covers • Use of scarves or masks for cold air • Avoid aspirin or NSAIDs • Desensitization can decrease sensitivity to allergens

36. Nursing ManagementHealth Promotion • Prompt diagnosis and treatment of upper respiratory infections and sinusitis may prevent exacerbation • Fluid intake of 2 to 3L every day

37. Nursing ManagementHealth Promotion • Adequate nutrition • Adequate sleep • Take -adrenergic agonist 10 to 20 minutes prior to exercising

38. Nursing ManagementNursing Implementation Acute Intervention • Monitor respiratory and cardiovascular systems • Lung sounds • Respiratory rate • Pulse • BP

39. Nursing ManagementNursing Implementation • ABGs • Pulse oximetry • FEV and PEFR • Work of breathing • Response to therapy

40. Nursing ManagementNursing Implementation • Nursing Interventions • Administer O2 • Bronchodilators • Chest physiotherapy • Medications (as ordered) • Ongoing patient monitoring

41. Nursing ManagementNursing Implementation An important goal of nursing is to decrease the patient’s sense of panic • Stay with patient • Encourage slow breathing using pursed lips for prolonged expiration • Position comfortably

42. Nursing ManagementNursing Implementation • The patient must learn about medications and develop self-management strategies • Patient and health care professional must monitor responsiveness to medication • Patient must understand importance of continuing medication when symptoms are not present

43. Nursing ManagementNursing Implementation • Important patient teaching: • Seek medical attention for bronchospasm or when severe side effects occur • Maintain good nutrition • Exercise within limits of tolerance

44. Nursing ManagementNursing Implementation • Important patient teaching (cont.): • Patient must learn to measure their peak flow at least daily • Asthmatics frequently do not perceive changes in their breathing

45. Nursing ManagementNursing Implementation • Counseling may be indicated to resolve problems • Relaxation therapies may help relax respiratory muscles and decrease respiratory rate

46. Nursing ManagementNursing Implementation Peak Flow Results • Greenzone • Usually 80-100% of personal best • Remain on medications

47. Nursing ManagementNursing Implementation Peak Flow Results • Yellow zone • Usually 50-80% of personal best • Indicates caution • Something is triggering asthma

48. Nursing ManagementNursing Implementation Peak Flow Results • Red zone • 50% or less of personal best • Indicates serious problem • Definitive action must be taken with health care provider