Approach to Dyspnea

1. Approach to Dyspnea Indiana University Department of Emergency Medicine MS IV Lecture Series

2. General Approach

3. General Approach

4. General Approach • Intervention may be needed immediately, before evaluation is complete • Intubation • CPAP/Bi-PAP • Nebs • Chest tube • Others

5. Assessing the severity: What are signs of respiratory distress?

6. Assessing the severity: • Vitals (tachypnea, abnormal HR) • Pulse oximetry • Position • Supine: reassuring; Tripod: worrisome • Speech – words per sentence • Retractions, accessory muscle use • Altered LOC, agitation • Diaphoresis

7. Intubate if not protecting airway

8. 2. Treat presumed etiology – educated guess based on: • Brief history • Known PMHx (a 20 yo with hx asthma is unlikely to be presenting with acute CHF) • Chest exam • Portable CXR

9. 3. Gather more data as the ptstabilizes • Refine treatment

10. History Onset • Sudden onset • consider PE, pneumothorax

11. History Associated chest pain? • Consider MI, PE, PTX, Pneumonia

12. History Orthopnea or PND? • Consider CHF

13. History Systemic symptoms? • Fever • Weight loss • Night sweats • Anxiety

14. History Past medical history • COPD • CHF • Asthma • Cancer • HIV • PE risk factors

15. Physical Examination • Respiratory rate (check it yourself) • Signs of respiratory distress • Auscultation

16. Physical Examination Beware: all that wheezes is not asthma • Pulmonary edema (“cardiac wheezing”) • Foreign body • Pulmonary infection • PE • Anaphylaxis • Many others

17. Ancillary Testing CXR Helpful for most patients with acute SOB • Infiltrates • Effusions • Pneumothorax • Pulmonary edema • Foreign bodies • Masses

18. Ancillary Testing CXR Helpful for most patients with acute SOB • Infiltrates • Effusions • Pneumothorax • Pulmonary edema • Foreign bodies • Masses

19. Ancillary Testing • CXR is not necessary in asthma exacerbations unless complication or alternative dx suspected

20. Ancillary Testing Other tests as dictated by the H&P: • Cardiac etiology suspected • EKG • Cardiac markers • BNP (CHF)

21. Ancillary Testing Other tests as dictated by the H&P: • D-dimer or CT if PE suspected

22. Ancillary Testing Other tests as dictated by the H&P: • Non-cardiopulmonary causes of dyspnea • CBC (anemia) • Metabolic Panel (metabolic acidosis)

23. Ancillary Testing Other tests as dictated by the H&P: • ABG usually not helpful

24. Arterial Blood Gas • Does it help determine the etiology of SOB?

25. Arterial Blood Gas • Critical Care. 2011; 15(3) • Retrospective analysis of 530 ED patients with acute dyspnea • Results: • “ABG analysis parameters were neither useful to distinguish between patients with pulmonary disorders and other causes of dyspnea nor to identify specific disorders responsible for dyspnea”

26. Case #1 • 15 yo male presents with severe SOB gradually worsening all day, associated with non-productive cough but no chest pain. • PMHx: Asthma • Meds: Albuterol MDI (took 6 doses today)

27. Case #1 • Sitting up in bed, visibly dyspneic, diaphoretic • VS: 1001F 110 28 146/86 95% RA • Normal mental status • Speaking in 3-4 word sentences • Chest: + retractions, diffuse wheezing What treatments do you want to start?

28. Treatment of Asthma Exacerbations Beta-agonists are the cornerstone • Albuterol, others • Usually given via nebulizer in ED • Intermittent dosing, usually 5mg/dose • Continuous neb • Somewhat more efficacious in severe asthma Cochrane Database Syst Rev. 2003;(4):CD001115.

29. Treatment of Asthma Exacerbations What about Levalbuterol (Xopenex)? • R-enantiomer of albuterol • Purported to have fewer side effects • Not consistently demonstrated in clinical studies • Albuterol generally well tolerated • Levalbuterol is expensive

30. Treatment of Asthma: Steroids • Corticosteroids treat the underlying airway inflammation • Improvement is seen within hours • Give first dose in the ED • Demonstrated to decrease hospital admissions • NNT=8 for moderate/severe exacerbations Cochrane Database Syst Rev. 2001;(1):CD002178

31. Treatment of Asthma: Steroids • Systemic steroids are better than inhaled for acute exacerbations • PO appears to be equivalent to IV

32. Treatment of Asthma: Steroids • Discharge patient with a 5-7 day “burst” • Prevents relapses • No taper necessary • Prednisone 40-60 mg/day

33. Treatment of Asthma: Anticholinergics • Ipratropium (atrovent) • MDI or Neb • Decrease airway secretions and smooth muscle tone • Slower onset and less effective bronchodilation than the b2-agonists • Minimal absorption; good side effect profile

34. Treatment of Asthma: Anticholinergics • Small benefit when used with b2-agonists over using b2-agonists alone • More effective in severe asthma • Usual dose: 0.5mg neb x 3 • Mix with albuterol

35. Asthma: other therapies Methylxanthines (theophylline) • Narrow therapeutic index • No clear benefit over b2-agonists alone • No longer used

36. Asthma: other therapies • Antibiotics: not helpful • IV fluids: no evidence that they improve sputum clearance

37. Asthma: other therapies Magnesium • Bronchodilation • Clinical effect: studies are mixed • Improved pulmonary function • No impact on hospital admission • Seems to be more helpful in severe asthma Emerg Med J. 2007; 24(12):823-30.

38. Asthma: other therapies Intubation/mechanical ventilation • Only as a last resort • Complications from barotrauma common • Not curative

39. Asthma: other therapies Intubation/mechanical ventilation • Ketamine = induction agent of choice • bronchodilator • Conventional tidal volumes and rate result in hyperinflation • difficulty getting the air out • permissive hypercapnia

40. Asthma: other therapies Non-invasive positive pressure ventilation • Bi-PAP, CPAP • May prevent the need for intubation in severe exacerbations

41. Severe Asthma • What are some risk factors for severe exacerbations/death? • Prior intubation or ICU admit • Multiple hospitalizations or ED visits for asthma • Current use of systemic steroids • Frequent use of rescue MDI • Comorbidities

42. Case #2 • 71 yo F presents with progressively increasing dyspnea for 4 days, much worse this morning. Mild non-productive cough. No chest pain. • + orthopnea: slept in chair last night • PMHx: DM, CAD, GERD

43. Case #2 • Vitals: 99F 106 212/104 32 87%RA • Awake, alert, anxious, sweaty, dyspneic • Diffuse rales • CXR:

44. Diagnosis? • Acute Decompensated CHF • What treatments do you want to begin?

45. CHF exacerbation: therapy Nitrates • Reduce preload • Cornerstone of therapy in the ED • SL, transdermal, or IV • Large amounts can be given SL very quickly

46. CHF exacerbation: therapy Furosemide (Lasix) • Reduces preload • diuresis • venodilation

47. CHF exacerbation: therapy Morphine • Time-honored treatment for CHF • Mechanism • decreased preload • decreased catecholamines • anxiolysis • Respiratory depression • Not a first-line (or even necessary) treatment

48. CHF exacerbation: therapy ACEIs • Effective in long-term management of CHF • Beneficial in acute exacerbations as well • Captopril may be given SL AcadEmerg Med. 1996;3:205-212

49. CHF exacerbation: therapy Noninvasive positive pressure ventilation • CPAP: Continuous Positive Airway Pressure • Bi-PAP: Bi-level Positive Airway Pressure • Different inspiratory (IPAP) and expiratory (EPAP) pressure levels • Delivered via tight-fitting mask over nose or mouth and nose

50. CHF exacerbation: therapy NIPPV • Decreases work of breathing • Increases functional residual capacity • Decreases preload (decreased venous return) • Benefit • Decreases need for intubation • Earlier resolution of symptoms • NO mortality benefit Health Technol Assess 2009;13(33):1–106