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Chapter 23 Obstructive Lung Disease: Chronic Obstructive Pulmonary Disease (COPD), Asthma, and Related Diseases Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. Learning Objectives State definitions of chronic obstructive pulmonary disease (COPD), asthma, and bronchiectasis. Identify how many Americans are diagnosed with COPD and how many deaths from COPD occur each year. Understand the major risk factors associated with the onset of COPD. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 2 Learning Objectives (cont.) Identify the common signs and symptoms associated with COPD. Describe a treatment plan for the patient with stable COPD and for the patient with an acute exacerbation. State the factors associated with the onset of asthma. Describe the clinical presentation typical for the patient with asthma. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 3 Learning Objectives (cont.) Identify the treatment currently available for the patient with acute asthma. Describe the treatment currently available for patients with bronchiectasis. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 4 COPD: Overview & Definitions COPD - inflammatory disorder characterized by not fully reversible, typically progressive, airflow obstruction Composed of 2 major disease entities: 1. 2. Emphysema Chronic bronchitis Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 5 COPD: Overview & Definitions Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 6 The COPD condition characterized by permanent enlargement of distal airspaces and destruction of the wall of the airspaces, without fibrosis is called: A. B. C. D. Asthma Cystic Fibrosis Emphysema Bronchiectasis Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 7 COPD: Epidemiology Incidence: ~24 million Americans have COPD COPD is 3rd leading cause of death in U.S. Number of deaths-per-year has continued to rise over years paralleling (with lag time) prior smoking trends Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 8 Risk Factors for COPD Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 9 Lung Decline Tied to Smoking Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 10 COPD Risk Factors & Pathophysiology Cigarette smoking’s impact on COPD mortality & morbidity far outweighs all other factors combined 2nd most common cause - AAT deficiency Genetic deficiency in AAT results in early onset emphysema Preventive measures may avoid early onset COPD • Smoking cessation key to managing disorder • Treatment with IV augmentation therapy may prevent neutrophil elastase damage to lung tissue Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 11 Cigarette Smoking & Emphysema Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 12 COPD Risk Factors & Pathophysiology (cont.) COPD may occur in absence of smoking or AAT deficiency Other risk factors: Passive smoking (second hand) Air pollution Occupational exposure AW hyperresponsiveness Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 13 The risk of developing emphysema for individuals with AAT deficiency increases as the level in the serum of AAT falls below: A. B. C. D. 11 µmol/L 8 µmol/L 13 µmol/L 20 µmol/L Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 14 COPD Risk Factors & Pathophysiology (cont.) Mechanisms of airflow limitation in COPD Inflammation & obstruction of small airways • Occurs in airways <2 mm in diameter Loss of elasticity • Destruction of elastin resulting in destruction of alveolar walls Active bronchospasm • Some element of reversibility is noted in 2/3rds of COPD patients Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 15 COPD: Signs & Symptoms Common symptoms Productive cough Wheezing or diminished breath sounds Shortness of breath (SOB); particularly on exertion Progressive dyspnea; usually manifesting in 6th or 7th decade of life (AAT deficiency ~45 years of age) Late signs include Barrel chest with flattened diaphragms Accessory muscle usage Edema from cor pulmonale Changes in mental status due to ⇓O2 or ⇑CO2 Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 16 Management of COPD Establishing diagnosis with airflow obstruction Separating COPD from asthma is major challenge Features favoring COPD are • Chronic productive cough, ⇓diffusing capacity • Diminished vascularity on chest radiograph Asthma favored if diminished FEV1 is normalized after use of an inhaled bronchodilator Once COPD established, check for AAT deficiency Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 17 During pulmonary rehab a COPD patient is told that in two months he should be able to go up to the second floor of his house without any shortness of breath. This goal is categorized as: A. B. C. D. prolong survival simplify medical treatment maximize functional status control airway flow obstruction Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 18 Optimizing Lung Function: Stable COPD PRN bronchodilator for all COPD patients Systemic corticosteroid trial (6–29% respond) Sympathomimetic &/or anticholinergic Reversibility if postbronchodilator FEV1 ⇑12% No survival benefit, but often improves symptoms If patient responds (⇑FEV1), use inhaled steroids Lung decline continues, but decreases exacerbations May lead to higher rate of pneumonia in COPD users Methylxanthines decrease feeling of dyspnea Try to avoid toxicity serum levels of 8–10 µg/mL Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 19 Optimizing Lung Function: Stable COPD (cont.) Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 20 Optimizing Lung Function: Acute Exacerbations Inhaled bronchodilators, especially 2-agonists Oral antibiotics if purulent sputum is present (7– 10 days) Short course of systemic corticosteroids Supplemental oxygen to keep SaO2 >90% With hypercapnia (pH <7.3), NIV is attractive option If NIV fails, then make decision on intubation & MV Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 21 Which of the following are criteria for a NIV trial on a patient suffering from a COPD exacerbation? 1. respiratory acidosis (pH <7.30) 2. hemodynamic stability 3. SpO2 <92% 4. Ability to protect the airway A. 1, 2and 3only B. 2 and 3only C. 1, 2, and 4 only D. 1 only Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 22 COPD: Maximizing Functional Status Primary goal is to maximize ability to perform daily tasks In addition to therapies mentioned previously: Comprehensive pulmonary rehabilitation is indicated for all Class II, III, & IV COPD patients • Improves exercise capacity • Upper body strength and ventilatory function Transcutaneous neuromuscular electrical stimulation Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 23 Preventing Progression & Enhancing Survival Smoking cessation is first-line intervention Long-term oxygen therapy (LTOT) Slows rate of FEV1 decline to same-age nonsmokers Enhanced survival rates Survival benefit noted with minimum 15 hours/day Closer to 24 hours/day is better Annual influenza & pneumococcal vaccinations Some end-stage COPD patients may benefit from lung transplant or lung volume reduction surgery Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 24 A pulmonologist orders pulmonary rehabilitation sessions for a 66 y/o COPD patient. Which of the following outcome should be expected from this intervention? A. Improve lung function B. Improve survival C. Decreased airway obstruction D. Decreased dyspnea perception Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 25 Preventing Progression of COPD & Enhancing Survival (cont.) Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 26 Asthma Definition Iinflammatory airway disease characterized by reversible airway obstruction Incidence Increasing prevalence in U.S. since 1980 Affects people of all ages Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 27 Asthma (cont.) Etiology & pathogenesis Genetic susceptibility to allergens, RTI, occupational and environmental stimuli, etc. Whatever trigger, it can produce “asthma” • Airway inflammation & bronchial hyperreactivity, resulting in airway obstruction • Once above are present, asthma can be triggered by: Exercise, cold dry air, hyperventilation, stress, cigarette smoke, etc…. • Once triggered, asthma causes mast cell degranulation, releasing proinflammatory substances Starts cycle of asthma Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 28 Asthma (cont.) Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 29 Early & Late Asthmatic Response Late response is usually more severe and longer lasting. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 30 Clinical Presentation & Diagnosis Diagnosis by clinical & laboratory evaluation History plays key role, as patients can be entirely normal between episodes Classic symptoms are episodic wheezing, SOB, cough If present, send for PFTs to demonstrate reversible airways obstruction PFTs may be normal between exacerbations or show some degree of airway obstruction ⇓FEV1 & FEV1/FVC ratio Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 31 Clinical Presentation & Diagnosis (cont.) Airway reversibility in asthma is noted just like in COPD If PFTs are normal, bronchoprovocation is undertaken Post-bronchodilator FEV1 ⇑12% & 200 ml Most common agent used: methacholine Arterial blood gases taken during an acute attack. Most often show hypoxemia with hyperventilation Normal PaCO2 level is indicative of severe attack & impending ventilatory failure Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 32 Asthma Management Goals of asthma management Maintain high-quality, asymptomatic life No limitations on the job or during exercise No medication side effects Stepwise approach to long-term management of asthma: Medication therapy is based on disease severity Control is attained when (there are) • Minimal to no daily symptoms or limitations • Infrequent exacerbations, with little or no use of 2-agonists • PFTs = normal or near normal Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 33 Asthma Management (cont.) Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 34 An asthmatic patient complains of nocturnal asthma attacks four times/wk. His current PFT exam shows and FEV1 of 82% predicted. The patient tells you that he takes levalbuterol TID and Advair 100/50 BID. The severity of his asthma should be classified as: A. Intermittent B. Mild persistent C. Moderate persistent D. Severe persistent Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 35 Pharmacotherapy Corticosteroids Most effective medication in treatment of asthma • Reduces symptoms & mortality Use of inhaled steroids for long-term treatment preferred • Use spacer & rinse mouth to eliminate or minimize side effects Long-term use of oral steroids should be restricted to patients with asthma refractory to other treatment Short-term oral steroid use during exacerbation reduces severity, duration, & mortality Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 36 Pharmacotherapy (cont.) Cromolyn (NSAID) Protective against allergens, cold air, exercise Administered prophylactically, CANNOT be used during an acute asthma attack Of limited use in adults Drug of choice for atopic children with asthma Nedocromil (NSAID) Similar to cromolyn, it is 4–10 times more potent in preventing acute allergic bronchospasm Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 37 Pharmacotherapy (cont.) Leukotriene inhibitors Leukotrienes mediate inflammation & bronchospasm Modestly effective to control mild to moderate asthma Inhaled steroids remain antiinflammatory drug of choice Methyxanthines (use is controversial) Oral or IV use if admitted for acute asthma attack Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 38 Pharmacotherapy (cont.) 2-Adrenergic agonists Most rapid & effective bronchodilator Drug of choice for exercise-induced asthma & emergency relief of bronchospasm • Should be used PRN Improves symptoms not underlying inflammation • Regular use may worsen asthma control & increase risk of death Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 39 Pharmacotherapy (cont.) Anticholinergics Can be used as adjunct to first-line bronchodilators if there is inadequate response Has additive affect to 2-agonists Tiotropium when added to corticosteroid enhances asthma control & improve symptoms Anti-IgE therapy: IgE plays role in asthma pathogenesis Omalizumab (Xolair) blocks IgE biologic effects Indicated in patients with allergic asthma, poorly controlled with corticosteroids Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 40 Emergency Management of Asthma Early & frequent use of aerosolized 2-agonists Consider continuous therapy for severe attack High-dose parenteral corticosteroids Oxygen therapy for hypoxemia Antibiotics if evidence of infection In severe ventilatory failure, use MV with permissive hypercapnia: small VT, low rate, PIP <50 cm H2O to avoid air-trapping & barotrauma Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 41 Bronchial Thermoplasty Promising new treatment for asthma patients Indicated for uncontrolled asthma despite use of corticosteroids & LABAs Uses heat (by ways of radiofrequency waves) to decrease airway smooth muscle mass Reduces ability of airways to constrict Long-term side effects have not been studied Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 42 Asthma & Environmental Control Recognized relationship between asthma & allergy 75–85% asthma patients react to inhaled allergens Environmental control is aimed at reducing exposure to allergens Avoid outdoor allergens by remaining inside, windows closed, AC on Indoor allergens are combated by: • Air purifiers & no pets • Dust mites: airtight covers on bed & pillow, no carpets in bedroom, chemical agents to kill mites Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 43 Special Considerations in Asthma Management Exercise-induced asthma (EIA) Occupational asthma Common particularly in cold weather • Heat loss from airways may precipitate attack Prophylactic inhalation of 2-agonists or cromolyn Most common form of occupational lung disease Early identification & cessation of exposure are key Cough-variant asthma Cough is sole complaint, amenable to 2-agonists Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 44 Special Considerations in Asthma Management (cont.) Nocturnal asthma Present in 2/3rds of poorly controlled asthmatics May be due to diurnal decrease in airway tone or gastric reflux Treatment should include: • Steroid treatment targeted to relieve night symptoms • Sustained release theophylline • New long-acting 2-agonists • Antacids for reflux Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 45 Special Considerations in Asthma Management (cont.) Aspirin sensitivity 5% of adult asthmatics will have severe, lifethreatening asthma attacks after taking NSAIDs All asthmatics should avoid; suggest Tylenol use Asthma during pregnancy 1/3rd of asthmatics have worse control at this time Much higher fetal risk associated with uncontrolled asthma than that of asthma medications Theophyllines, 2-agonists, & steroids can be used without significant risk of fetal abnormalities Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 46 Special Considerations in Asthma Management (cont.) Sinusitis may cause asthma exacerbation CT of sinuses will diagnosis problem Treatment: 2–3 weeks antibiotics, nasal decongestants, & nasal inhaled steroids Surgery Asthmatics at higher risk for respiratory complications: • Arrest during induction • Hypoxemia with/without hypercarbia • Impaired cough, atelectasis, pneumonia Optimize lung function preoperatively Use steroids during procedure. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 47 Asthma caused by rapid inhalation associated with physical exertion can be classified as: A. Occupational asthma B. Cough-variant asthma C. Exercise-induced asthma D. Nocturnal asthma Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 48 Bronchiectasis Abnormal, irreversible dilation of bronchi caused by chronic airway inflammation & destruction Presents in 3 major anatomical patterns Cylindrical: airway is uniformly dilated 2. Varicose: irregular constrictions & dilations 3. Cystic: progressive distal, sac-like dilations 1. Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 49 Bronchiectasis (cont.) Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 50 Bronchiectasis (cont.) Clinical presentation & evaluation Hallmark: chronic production of copious amounts of purulent sputum Dyspnea variable; depends on extent of disease Hemoptysis frequent, though rarely severe Chest radiograph shows tram lines (airway dilation) Definitive diagnosis made with fine-cut CT • Reversible airway changes consistent with bronchiectasis may follow pneumonia • Wait 6–8 weeks following pneumonia resolution Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 51 Bronchiectasis (cont.) Mainstays of Management Antibiotics • As needed or regularly scheduled • Sputum cultures should guide therapy Bronchopulmonary hygiene • Postural drainage & cough maneuvers • Humidification & hyperosmolar substances • Dry powder inhaled mannitol may be helpful Massive hemoptysis may embolize artery or surgically repair Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 52 RT Role in COPD Diagnostic role: Performing PFTs Physical assessment Management: Medication delivery, bronchial hygiene, oxygen delivery Invasive/Non-invasive ventilatory support Invasive/Non-invasive blood gas monitoring Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 53 RT Role in COPD (cont.) Follow up: Smoking cessation Pulmonary rehab Long-term oxygen therapy Invasive/Non-invasive ventilatory support Advocacy Copyright © 2013, 2009, 2003, 1999, 1995, 1990, 1982, 1977, 1973, 1969 by Mosby, an imprint of Elsevier Inc. 54