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Chronic Obstructive Pulmonary Disease (COPD)Chapter 29

Copyright 2014 by Mosby, an imprint of Elsevier Inc.1COPD DescriptionAirflow limitation not fully reversibleGenerally progressiveAbnormal inflammatory response of lungs to noxious particles or gases Copyright 2014 by Mosby, an imprint of Elsevier Inc.2Chronic obstructive pulmonary disease (COPD) is a preventable and treatable disease.COPD also results in some significant systemic effects that contribute to the severity of disease exhibited in individual patients.

COPDDescriptionIncludesChronic bronchitisEmphysema Copyright 2014 by Mosby, an imprint of Elsevier Inc.3Chronic bronchitis is the presence of chronic productive cough for 3 months in each of 2 consecutive years in a patient in whom other causes of chronic cough have been excluded. Emphysema is an abnormal permanent enlargement of the air spaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis. Patients may have a predominance of one of these conditions, but in reality this is often difficult to determine because the conditions usually coexist. COPDSignificanceThird leading cause of death in the United StatesKills more than 120,000 Americans each year Copyright 2014 by Mosby, an imprint of Elsevier Inc.4An estimated 13.1 million adults in the United States older than age 18 have COPD. Persons with COPD are greatly underestimated because the disease usually is not diagnosed until it is moderately advanced.

COPDEtiologyRisk factorsCigarette smokingOccupational chemicals and dustAir pollution Copyright 2014 by Mosby, an imprint of Elsevier Inc.5In persons over age 40 with a smoking history of 10 or more pack years, COPD should be considered.COPDEtiologyRisk factorsInfection HeredityAging

Copyright 2014 by Mosby, an imprint of Elsevier Inc.6COPDCigarette SmokingClinically significant airway obstruction develops in 15% of smokers.80% to 90% of COPD deaths are related to tobacco smoking. Copyright 2014 by Mosby, an imprint of Elsevier Inc.7COPD is more than 4 times as prevalent among smokers as nonsmokers.

COPDCigarette SmokingEffects of nicotineStimulates sympathetic nervous systemIncreases HRCauses peripheral vasoconstrictionIncreases BP and cardiac workload

Copyright 2014 by Mosby, an imprint of Elsevier Inc.8COPDCigarette SmokingEffects of nicotine Amount of functional hemoglobin Platelet aggregationCompounds problems in CAD

Copyright 2014 by Mosby, an imprint of Elsevier Inc.9COPDCigarette SmokingEffects on respiratory tractIncreased production of mucusHyperplasia of goblet cellsIncreased production of mucusLost or decreased ciliary activityChronic, enhanced inflammation Copyright 2014 by Mosby, an imprint of Elsevier Inc.10See Table 29-16 for the direct effects of smoking on the respiratory tract.Smoking causes chronic, enhanced inflammation of various parts of the lung with structural changes and repair (called remodeling).The reasons for the inflammatory response are not clearly understood, but may be genetically determined as patients can develop COPD who have never smoked.

COPDCigarette SmokingCarbon monoxide O2 carrying capacity Heart rateImpaired psychomotor performance and judgment Copyright 2014 by Mosby, an imprint of Elsevier Inc.11COPDCigarette SmokingPassive smoking (secondhand smoke) Pulmonary function Risk of lung cancer Respiratory symptoms

Copyright 2014 by Mosby, an imprint of Elsevier Inc.12Also known as environmental tobacco smoke (ETS).Also increased risk for nasal sinus cancer.

COPDOccupational & EnvironmentalCOPD can develop with intense or prolonged exposure toDusts, vapors, irritants, or fumesHigh levels of air pollutionFumes from indoor heating or cooking with fossil fuels. Copyright 2014 by Mosby, an imprint of Elsevier Inc.13The effect of outdoor air pollution as a risk factor for the development of COPD is unclear.Use of coal and other biomass fuels for indoor heating and cooking are also a risk factor. Many women, particularly worldwide, who have never smoked are developing COPD because of cooking with these fuels in poorly ventilated areas.

COPDInfection Recurring infections impair normal defense mechanismsHIVTuberculosis Copyright 2014 by Mosby, an imprint of Elsevier Inc.14Severe recurring respiratory tract infections in childhood have been associated with reduced lung function and increased respiratory symptoms in adulthood, while it is unclear if recurrent infections in adults are related to development of COPD.People who smoke and also have HIV have an accelerated development of COPD. Tuberculosis is also a risk factor for COPD development.

COPDHeredity-Antitrypsin (AAT) deficiencyGenetic risk factor for COPDAccounts for 3% of COPDAAT is an autosomal recessive disorder. Copyright 2014 by Mosby, an imprint of Elsevier Inc.15AAT, a 1-protease inhibitor, is a serum protein produced by the liver and normally found in the lungs. Its main function is to protect normal lung tissue from attack by proteases during inflammation related to cigarette smoking and infections.Severe AAT deficiency leads to premature bullous emphysema in the lungs found on x-ray. Emphysema occurs because of AAT deficiency. Lower levels of AAT result in insufficient inactivation and subsequent destruction of lung tissue. The most common abnormal genes are the S and Z alleles; normal genes are labeled M. The most common genotype associated with AAT disease is ZZ. A simple blood test can determine low levels of AAT. Those with borderline or low levels can then be genetically tested.IV-administered AAT (e.g., Prolastin-C) augmentation therapy is used for persons with AAT deficiency. COPDAgingSome degree of emphysema is common because of physiologic changes of aging lung tissue. Copyright 2014 by Mosby, an imprint of Elsevier Inc.16As people age, gradual loss of the elastic recoil of the lung occurs, along with stiffening of the chest wall, gas exchange alteration, and decrease in exercise tolerance. The lungs become more rounded and smaller. The number of functional alveoli decreases as peripheral airways lose supporting tissues. These changes are similar to those seen in the patient with emphysema. Clinically significant emphysema, however, usually is not caused by aging alone.

Case StudyG.S., a 77-year-old man, comes to the hospital complaining of shortness of breath, morning cough, and swelling in his lower extremities.He has difficulty breathing when he walks short distances, such as to the bathroom.

Copyright 2014 by Mosby, an imprint of Elsevier Inc.iStockphoto/ThinkstockWe will now discuss a case study of a patient with COPD.Have students discuss risk factors for this patient.What questions do you need to ask him related to risk factors?Do you or have you ever smoked?If yes, how much, and for how long?Do you have any family history of lung disease?Where have you worked, types of jobs?17COPDPathophysiologyDefining featuresIrreversible airflow limitations during forced exhalation due to loss of elastic recoilAirflow obstruction due to mucous hypersecretion, mucosal edema, and bronchospasm Copyright 2014 by Mosby, an imprint of Elsevier Inc.18COPD is characterized by chronic inflammation found in the airways, lung parenchyma (respiratory bronchioles and alveoli), and pulmonary blood vessels. The pathogenesis of COPD is complex and involves many mechanisms. COPDPathophysiologyPrimary process is inflammation.Inhalation of noxious particlesMediators released cause damage to lung tissue.Airways inflamedParenchyma destroyed Copyright 2014 by Mosby, an imprint of Elsevier Inc.19(See next slide for figure.)The mechanisms for the enhanced inflammatory response are not clearly understood but may be genetically determined.

COPDPathophysiologyCopyright 2014 by Mosby, an imprint of Elsevier Inc.

20In COPD various disease processes occur such as airflow limitation, air trapping, gas exchange abnormalities, mucous hypersecretion, and, in severe disease, pulmonary hypertension with systemic features.

COPDPathophysiologySupporting structures of lungs are destroyed.Air goes in easily, but remains in the lungs.Bronchioles tend to collapse.Causes barrel-chest look Copyright 2014 by Mosby, an imprint of Elsevier Inc.21Inability to expire air is a main characteristic of COPD. The primary site of the airflow limitation is in the smaller airways.The volume of residual air becomes greatly increased in severe disease as alveolar attachments to small airways (similar to rubber bands) are destroyed. The patient tries to breathe in when the lungs are in an overinflated state; thus the patient appears dyspneic, and exercise capacity is limited.

Copyright 2014 by Mosby, an imprint of Elsevier Inc.COPDPathophysiology

Gas exchange abnormalities result in hypoxemia and hypercarbia (increased CO2) as the disease worsens. As the air trapping worsens and alveoli are destroyed, bullae (large air spaces in the parenchyma) and blebs (air spaces adjacent to pleurae) can form.

22COPDPathophysiologyCommon characteristicsMucus hypersecretionDysfunction of ciliaHyperinflation of lungsGas exchange abnormalities Copyright 2014 by Mosby, an imprint of Elsevier Inc.23Excessive mucous production resulting in chronic cough is characteristic of chronic bronchitis.

COPDPathophysiologyPulmonary vascular changes Blood vessels thicken.Surface area for diffusion of O2 decreases.Results in pulmonary hypertension Copyright 2014 by Mosby, an imprint of Elsevier Inc.24Because of the loss of alveolar walls and the capillaries surrounding them, there is increased pressure in the pulmonary circulation. This, along with thickening of the blood vessels, results n pulmonary hypertension.

COPDPathophysiologyCOPD is a systemic disease as a result of chronic inflammation.Often coexists with heart disease

Copyright 2014 by Mosby, an imprint of Elsevier Inc.25Other common systemic diseases include cachexia (skeletal muscle wasting), osteoporosis, diabetes, and metabolic syndrome, which cannot be readily related to smoking.

Case StudyG.S. states that he sleeps in a recliner to make it easier to breathe. He feels his shoes are tight at the end of the day.He is placed on oxygen at 2 liters/minute via nasal cannula.

Copyright 2014 by Mosby, an imprint of Elsevier Inc.iStockphoto/ThinkstockHave students formulate questions to explore G.S. additional symptoms.What are your priorities regarding assessment?What assessment findings can you expect?(See next slides for clinical manifestations.)26COPDClinical ManifestationsDevelops slowlyDiagnosis is considered withCoughSputum productionDyspneaExposure to risk factors Copyright 2014 by Mosby, an imprint of Elsevier Inc.27Clinical manifestations of COPD typically develop slowly and should be considered in patients over 40 years of age, and after 20 pack-years of cigarette smoking.A chronic intermittent cough usually occurs in the morning and may or may not be productive of small amounts of sticky mucus. These symptoms can occur many years before actual airflow limitation.

COPDClinical ManifestationsDyspnea usually prompts medical attention.Occurs with exertion in early stagesPresent at rest with advanced disease Copyright 2014 by Mosby, an imprint of Elsevier Inc.28Dyspnea typically is progressive, usually occurs with exertion, and is present every day. Patients usually ignore the symptoms and rationalize that, Im getting older and Im out of shape. They change behaviors to avoid dyspnea, such as by taking the elevator. Gradually, the dyspnea interferes with daily activities, such as carrying grocery bags, and they cannot walk as fast as their spouse or peers.

COPDClinical ManifestationsCauses chest breathingUse of accessory and intercostal musclesInefficient breathingMay experience chest tightness with activity Copyright 2014 by Mosby, an imprint of Elsevier Inc.29Wheezing and chest tightness may be present but may vary by time of day or from day to day, especially in patients with more severe disease.

COPDClinical ManifestationsCharacteristically underweight with adequate caloric intakeChronic fatigue Copyright 2014 by Mosby, an imprint of Elsevier Inc.30Even when the patient has adequate caloric intake, weight loss is experienced. Fatigue is a highly prevalent symptom that affects the patients activities of daily living.

COPDClinical ManifestationsPhysical examination findingsProlonged expiratory phaseWheezesDecreased breath sounds Anterior-posterior diameter (barrel chest)Tripod positionPursed lip breathing

Copyright 2014 by Mosby, an imprint of Elsevier Inc.31The patient may need to breathe louder than normal for auscultated breath sounds to be heard. The patient may sit upright with arms supported on a fixed surface such as an overbed table (tripod position). The patient may naturally purse lips on expiration (pursed lip breathing) and may use accessory muscles, such as those in the neck, to aid with inspiration.

COPDClinical ManifestationsBluish-red color of skinPolycythemia and cyanosis Copyright 2014 by Mosby, an imprint of Elsevier Inc.32Over time, hypoxemia (PaO2