بسم الله الرحمن الرحیم

1. بسم الله الرحمن الرحیم

2. Emergency Treatment of Asthma

3. Presented by MehrzadBahtouee, MD Internist, Pulmonologist Assistant Professor of Internal Medicine Boushehr University of Medical sciences

4. Introduction • A common diseases • Worldwide prevalence of 7 to 10% • A common reason for urgent care and emergency department visits • Children > Adults, Black > whites, Hispanics > Non-Hispanics, Women > Men (twice)

5. Introduction (continued) • 10% → hospitalization • Difference in responsiveness to treatment ( Degree of airway inflammation, Presence or absence of mucus plugging, Individual responsiveness to β2-adrenergic and corticosteroid medications) • Which patients can be discharged quickly and which need to be hospitalized

6. INITIAL ASSESSMENT IN THE EMERGENCY DEPARTMENT • Quick evaluation and triage to assess the severity of the exacerbation and the need for urgent intervention • A brief history and a limited physical examination, not delaying treatment • Search for signs of life threatening asthma (e.g., altered mental status, paradoxical chest or abdominal movement, absence of wheezing) • Factors associated with an increased risk of death from asthma: previous intubation or admission to an ICU, two or more hospitalizations for asthma during the past year, low socioeconomic status, coexisting illnesses

7. INITIAL ASSESSMENT IN THE EMERGENCY DEPARTMENT (continued) • Measurement of lung function (FEV1, PEF) → Severity, response to treatment • Laboratory and imaging studies selectively, (e.g., partial pressure of arterial carbon dioxide [PaCO2]), complete blood count or a chest radiograph, electrocardiogram)

16. TREATMENT IN THE EMERGENCY DEPARTMENT • All patients → • a) supplementary oxygen to achieve an arterial oxygen saturation of 90% or greater • b) inhaled short-acting β2- adrenergic agonists • c) systemic corticosteroids

18. β2-Adrenergic Agonists • Administered immediately on presentation • Repeated up to three times within the first hour after presentation • Use of a metered-dose inhaler with a valved holding chamber as effective as the use of a pressurized nebulizer in randomized trials • Use of nebulizers for patients with severe exacerbations

19. β2-Adrenergic Agonists (continued) • Metered dose inhalers with holding chambers in mild to moderate exacerbations, • Albuterol: four to eight puffs of albuterol can be administered every 20 minutes for up to 4 hours and then every 1 to 4 hours as needed • Oral or parenteral administration of β2-adrenergic agonists is not recommended

20. Anticholinergic Agents • Slow onset of action, inhaled ipratropium • Not recommended as monotherapyin the emergency department • Added to a short acting β2-adrenergic agonist for a greater and longer lasting bronchodilator effect in exacerbations • Reduces rates of hospitalization by approximately 25%

21. Systemic Corticosteroids • Needed in most patients with exacerbations that necessitate treatment in the emergency department • More rapid improvement in lung function, fewer hospitalizations, and a lower rate of relapse after discharge from the emergency department • No differences in the rate of improvement of lung function or in the length of the hospital stay between oral and parenteralsteroid

22. Systemic Corticosteroids (continued) • Oral route is preferred for patients with normal mental status and without conditions expected to interfere with gastrointestinal absorption • 40 to 80 mg per day in one dose or two divided doses

25. Inhaled Corticosteroids • Not suitable as a substitute for systemic corticosteroids in the emergency department • Preferred for long-term asthma control • Addition at the time of discharge of inhaled steroid → reduction in the rate of relapse, as compared with oral corticosteroids alone

26. Treatments not recommended • Methylxanthines: increasing the risk of adverse events without improving outcomes • Antibiotics: except for bacterial infections (e.g., pneumonia or sinusitis) • Aggressive hydration and mucolytic agents

28. ASSESSMENT OF RESPONSE TO TREATMENT • After the first treatment with an inhaled bronchodilator and again at 60 to 90 minutes (i.e., after three treatments) • Survey of symptoms, a physical examination, and measurement of FEV1 or PEF • Measurement of ABG in most severe exacerbations • Need for hospital admission as well as site of admission is better predicted by the assessment of asthma severity after 1 hour of treatment • Admit or discharge according to subjective and objective improvement after one hour of initial treatment

29. INDICATIONS FOR ADMISSION • FEV1 of less than 40% • Persistent moderate to severe symptoms • Drowsiness • Confusion • PaCO2 of 42 mm Hg or greater • FEV1 of 40 to 69% and mild symptoms → assess individually for risk factors for death, ability to adhere to a prescribed regimen, and the presence of asthma triggers in the home

30. MANAGEMENT OF RESPIRATORY INSUFFICIENCY • Immediate intubation and ventilatory support in patients with altered mental status, exhaustion, or hypercapnia • Risk of hypotension and barotraumas during positive pressure ventilation due to high positive intrathoracic pressures • Ventilation using permissive hypercapnia strategy → decreased mortality among patients with status asthmaticus

31. MANAGEMENT OF RESPIRATORY INSUFFICIENCY (continued) • Intubation in a semi­ elective and controlled conditions (vs. performed as an emergency procedure by the first available staff) • Noninvasive positive pressure ventilation: recommended for acute exacerbations of COPD but ?? for Asthma

32. DISCHARGE FROM THE EMERGENCY DEPARTMENT • FEV1 or PEF after treatment is 70% or more of the personal best or predicted value • Improvements in lung function and symptoms sustained for at least 60 minutes • Use of short acting β2-adrenergic agonists inhalers as needed • Oral corticosteroids for 3 to 10 days • Corticosteroid inhaler to reduce the risk of relapse

34. EDUCATION OF PATIENTS • Educate patients about medications, inhaler technique, and steps that can reduce exposure to household triggers of allergic reaction

35. NEWER STRATEGIES • Use of IV magnesium sulfate in severe exacerbations and also FEV1 or PEF less than 40% of the personal best or predicted value after initial treatments • Heliox: density about one third that of air, reduction of airflow resistance within and work of breathing and improvement in delivery of aerosolized medication • Antileukoterines ??

39. Reference: • N Engl J Med 2010;363:755-64 Emergency Treatment of Asthma. Stephen C. Lazarus, M.D NIH guidline