COPD/asthma

1. COPD/asthma Written by Mick Svoboda D.O. Presented by Dr Moosally D.O.

3. COPD definition • COPD is characterized by airflow limitation that is not fully reversible. Airflow obstruction is progressive and associated with an abnormal inflammatory response to noxious particles or gases.

4. Pathophysiology • Airway changes 2˚ to noxious stimuli • Increase in number and size of bronchial mucous glands • ↑ secretions • Acute and chronic airway inflammation • ↑ airway resistance • Breakdown in alveolar architecture • Hypoxemia 2˚ to V/Q mismatch

5. Chronic Signs/Symptoms • Classic signs • Exertional dyspnea • Cough • Symptoms • Tachypnea • Accessory muscle use • Pursed lip exhaling • Decreased breath sounds • Wheezing upon exhalation • Prolonged exhelation • Barrel chest • Findings or right ventricular strain

6. Acute Signs/Symptoms • Acute decompensation characterized by • Progressive hypoxemia • Tachypnea • Cyanosis • AMS • Increased work of breathing

7. Diagnosis of chronic, compensated COPD • PFTs • Ratio FEV1:FVC < 70% • Indicates obstructive disease • Value of FEV1 • Indicates severity of disease • DLCO < 80% • Differentiates between chronic bronchitis and emphysema

8. Diagnosis of acute exacerbations • Assess hypoxemia • Pulse ox • Assess hypercapnea/ acid-base disturbances • ABGs • Bedside PFTS if available • Often unreliable 2˚ to poor pt cooperation • Assess sputum • Look for changes in color, volume, and consistency • Culture • CXR • Look for underlying etiology

9. Treatment • Chronic treatment • Lifestyle changes • #1 smoking cessation • Oxygen • Home O2 indicated for PaO2 < 55% or SaO2 < 88% • Meds • Do not reduce mortality, but provide symptomatic relief • Β2agonist, anticholinergics

10. Treatment • Acute treatment • Oxygen • Maintain SaO2 > 90% • Bronchodilator therapy • Β2agonist, anticholinergics, or combination therapy • Aerosolized tx preferred • When using Β2agonist in pt with known heart disease, consider placing on cardiac monitor

11. Treatment (cont) • Corticosteroids • IV solumedrol 125mg • PO prednisone 60mg • Consider abx therapy if suspect infection • Appropriate tx based on whether pt is from nursing home/community • Consider NIPPV • BiPAP/CPAP • Indications for mechanicalventilation • Resp muscle fatigue • ABG signs of worsening resp acidosis • Declining mental status 2˚ to hypercapnea • Significant hypoxemia

12. Exacerbation/Mortality • With each exacerbation pts never return to their baseline pulmonary ftn. • As a consequence pt mortality rises with each exacerbation regardless of therapeutic intervention.

13. Disposition • Pt who fail to improve adequately or continue to deteriorate require hospitalization. • Pt stable for d/c to home should have the following • Adequate home O2 if needed • Bronchodilator txs • Short course of PO steroids if necessary • Abx if indicated • Secure follow up with PCP

14. Asthma definition • A chronic inflammatory disorder characterized by increased responsiveness of the airways to multiple stimuli.

15. Pathophysiology • Reduction in airway diameter • Smooth muscle contraction • Vascular congestion • Bronchial wall edema • Thickened secretions • Consequences • Air trapping (intrinsic PEEP) • Increased work of breathing • V/Q imbalance w/ resulting hypercapnea/hypoxia

16. Clinical features • Classic triad • Dyspnea • Wheezing ( may be absent in severe cases) • Cough • Other sxs • Chest tightness • Prolonged expiration • Accessory muscle use • Tachypnea • Paradoxical abd breathing* • AMS* *signs of impending resp failure

17. Disorders w/ wheezing may mimic asthma • CHF “cardiac asthma” • Upper airway obstruction • FB aspiration • Multiple pulmonary emboli • Vocal cord dsftn • pneumonia

18. Key elements of history regarding asthma exacerbations • Present management and medications • Hospital admissions for exacerbations • ER visit in past year/month for exacerbations • Exposure to asthma triggers • Use of home peak flow meters • Best way to predict future exacerbation before it occurs • History of intubations

19. diagnosis • PEFR • Can determine severity and response to therapy if pt is cooperative. • Assess hypoxemia • Pulse ox • ABG • Indicated in severe exacerbation to assess hypercapnea and acidosis. • CXR unnecessary unless indicated by physical exam findings

20. Treatment • Goal- reverse airway obstruction • Adrenergic agents • β-adrenergic agents preferred as initial tx for bronchospasm • Albuterol, xopenex (continuous/intermittent) • Best response w/ aerosol txs and ↓ severity side effects • Common side effects • Tachycardia ( less w/ xopenex) • Nervousness/anxiety • Palpitations • Insomnia • tremors

21. Treatment (cont) • Corticosteroids • IV solumedrol 125mg • PO prednisone 40-60mg • Mechanism unknown, but benefit believed to be from • Effect to restore β-adrenergic responsiveness • Anti-inflammatory effects • Evidence suggests that steroid given within 1 hour of arrival to ED reduces need for hospitalization.

22. Treatment (cont) • Anticholinergics • Can be given to pt in form of nebulized treatment alone or in combination with β-adrenergic. • Magnesium • Indicated for severe asthma exacerbation. • 1-2g IV over 30 min. • Mechanical ventilation • Required pts who • Have signs of impending resp failure • Fail NIPPV

23. Disposition • Decision to admit pt vs. discharge to home should be based on • Resolution of wheezing and improvement in air exchange • Pt with PEFR ≥ 70% predicted can be safely discharged to home. • Decision should also be guided by past/recent admissions for exacerbation indicating poor control/compliance.