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Chronic Bronchitis....continued from page 9 V/Q disturbances lead to hypoxemia, hypercapnia, and


acidemia, all of which cause pulmonary vasculature constriction. This condition of the pulmonary circulation forces the right ventricle to pump harder in order to achieve adequate blood flow through more narrow pulmonary vessels. In addition to working against an increased pulmonary vascular resistance, the right ventricle must also pump blood that is more viscous. The blood’s viscosity in- creases in response to increased red blood cells in circulation. The chronic hypoxemia stimulates the release of erythropoietin in the blood to increase erythrocyte production in an effort to improve the blood’s oxygen carrying capacity. Over time, the right ventricle in- creases muscle mass (right ventricular hypertrophy), and eventually will fail. The failure of the right ventricle resulting from lung disease is termed cor pulmonale.


CLINICAL MANIFESTATIONS Clinical manifestations of chronic bronchitis vary according to


the stage of the condition. Patients having mild chronic bronchitis demonstrate unremarkable physical findings, whereas those with severe disease display a variety of signs and symptoms. The onset of this condition is usually insidious, starting with "the smoker’s cough." The sputum tends to be mucoid in the absence of a pul- monary infection. Patients often experience immoderate coughing and sputum production in the mornings upon awakening. When a patient with chronic bronchitis contracts a lower respiratory tract infection, sputum changes to a yellowish green and becomes thicker and purulent. Patients also frequently complain of becoming short of breath


when performing common household activities. Over the years, this exertional dyspnea progresses to dyspnea at rest. Observation of the patient often reveals a prolonged expiratory phase. The presence of accessory muscle use is more indicative of severe airway obstruc- tion. Patients also appear to be somewhat overweight, and in the later stages of the condition, cyanotic. This appearance has given rise to the expression "blue bloater." Auscultation may reveal coarse inspiratory crackles as air moves through airways filled with secre- tions. Wheezing may occur during exertion but is more likely to be heard during an exacerbation. Chest radiography tends to be unremarkable in the early stages,


but in the advanced stages reveals hyperinflation and increased vas- cular markings. Depending on the stage, arterial blood gas data range from hypoxemia and normocapnia in mild chronic bronchitis to worsened hypoxemia, hypercapnia, and acidemia in the severe form. Pulmonary function values also vary according to the degree of air flow obstruction. Commonly, all the expiratory flow compo- nents of the forced expiratory vital capacity are reduced, i,e., the PEF, FEV1, FEV1%, FEF 25%-75%, and FEF 200-1200. Clinical ev- idence has shown that the rate of decline of the FEV1 reflects the progression of the disease. The RV and FRC are generally increased. The DLCO is often normal.


DIAGNOSIS Chronic bronchitis is defined on a clinical basis as the presence


of a persistent, productive cough and increased pulmonary secre- tions on most days for a minimum of three consecutive months for, at least, two successive years. The diagnosis of chronic bronchitis is based on this clinical definition and the demonstration of air flow obstruction via spirometry. Accurate diagnosis and the degree of air flow obstruction can


only be ascertained through spirometry. Assessing forced expiratory vital capacity data serves a two-fold purpose: quantifying the sever-


10 Focus Journal Spring 2011


ity of the air flow obstruction and evaluating its reversibility. The FVC, FEV1, and FEV1% are central to the diagnosis and manage- ment of chronic bronchitis. Demonstrating some degree of air flow obstruction using spirometry and obtaining a normal DLCO rules out emphysema, which features diminished expiratory flow rates and a decreased DLCO.


MANAGEMENT OF CHRONIC BRONCHITIS Smoking cessation and promoting a healthy life style are nec-


essary to slow the progression of chronic bronchitis, and for treat- ment to be effective. In addition to quitting smoking, patients with chronic bronchitis should avoid environments that have poor quality air such as industrial contaminants and atmospheric pollutants. Avoidance of second-hand smoke is equally important. Home oxygen is necessary if the patient has documented hy-


poxemia, indicated by an arterial PO2 of less than or equal to 55 torr, or an arterial SO2 of 89% or less while breathing room air ei- ther at rest, during exercise, or during sleep. Oxygen therapy dur- ing sleep may be necessary despite not meeting the qualifications for oxygen at rest. Evidence of cor pulmonale is an indication for oxygen therapy. Antibiotics are indicated for patients who have moderate to se-


vere symptoms, and experience either an increased volume or change in character (mucoid to purulent) of secretions. Antibiotics are indicated for patients having an exacerbation. The antibiotic pre- scribed should be effective against Hemophilus influenzae, Strepto- coccus pneumoniae, and Moraxella catarrhalis. Empirical data support the effectiveness of annual influenza


vaccinations and a one-time pneumococcal vaccination. These measures of prevention are known to reduce the morbidity and mortality in patients with chronic bronchitis. Avoiding contact with known cold sufferers, especially those in the first three days of a cold, is encouraged Patients who meet the criteria of reversible airway obstruction,


i.e., a post-bronchodilator FEV112% and 200 ml greater than the pre-bronchodilator FEV1, benefit from a beta-2 agonist such as al- buterol or salmeterol, administered through a metered dose inhaler (MDI). Clinical evidence has demonstrated that many chronic bron- chitics respond more favorably to ipratropium bromide (Atrovent), an anticholinergic bronchodilator, than they do to adrenergic bron- cholidators (sympathmimetics). Combivent, which comes in a me- tered dose inhaler containing both ipratropium bromide and albuterol, seems to be beneficial for many patients with this disease. The administration of inhaled corticosteroids via an MDI to pa-


tients with chronic bronchitis, or COPD in general, is somewhat con- troversial. Most of the literature states that inhaled corticosteroids play no role in the treatment and management of these conditions. However, clinical practice often dictates otherwise. Many patients with chronic bronchitis, especially those demonstrating airway re- versibility, are frequently prescribed fluticasone propionate (Flovent), or Advair Diskus (fluticasone propionate and salmeterol), as well as other inhaled coticosteroids. Participating in a pulmonary rehabilitation program is encour-


aged to lessen symptoms, to promote personal independence, to im- prove physical conditioning, to strengthen emotional well-being, and to reduce hospitalizations. Because chronic bronchitis is essen- tially a preventable disease, behavior modification plays a major role in its management. Health care providers must assume an active role in health pro-


motion by strongly advocating smoking cessation because cigarette smoking is the cause of many chronic diseases.


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