COPD: Pathogenesis, Epidemiology, and the Role of Cigarette Smoke

10. Medical Management

Severity in COPD is defined by the degree of expiratory airflow obstruction, expressed as FEV1 as a percent of predicted value. The GOLD stages are defined as Stage I (FEV₁% > 80% predicted), Stage II (FEV₁% < 80% but > 50% predicted), Stage III (FEV_1,% < 50% but >30% predicted), and Stage IV (FEV₁%, <30% predicted). Management is based on the stage of disease (Figure 4) (Figure 5).

For Stage I disease, smoking cessation is the main goal. If smoking cessation is successful at this stage, progression to more severe disease may be prevented and cardiovascular and cancer risks reduced.

For Stage II disease, smoking cessation and symptomatic therapies are both considered (Figure 3). Symptomatic therapies include both short- and long-acting beta-agonists (LABA) and long-acting anti-muscarinics (LAMA). Although most therapies approved for Stage II disease offer no survival benefit, recent data suggest that, in some patients, some therapies may decrease the frequency of exacerbations and may provide a survival benefit. The longest-acting agents may provide the greatest benefit. Therapeutic decisions in Stage II and Stage III disease can be considered with regard to those that improve symptoms alone, those that prevent exacerbations, and those that may be shown to improve survival.

Stage IV disease is commonly accompanied by hypoxemia. Treatment of significant hypoxemia (PaO₂< 55 mm Hg) with supplemental oxygen provides a survival benefit that is greater for those treated continuously throughout the day than for those treated only nocturnally. Compelling evidence is lacking for use of supplemental oxygen for less severe hypoxemia, even in patients who have severe airflow obstruction and dyspnea. Only patients with significant hypoxemia have improvement in exercise capacity with use of supplemental oxygen.

Chronic nocturnal ventilation may be utilized for symptomatic hypercarbia and may result in clinical improvement; however, its use may not improve the patient's ability to perform activities of daily living, nor may it confer a survival benefit. Pulmonary rehabilitation can be utilized for any disease stage; however, since health insurance benefits are commonly limited, rehabilitation therapy is usually prescribed only for those with severe disease and limited abilities to perform activities of daily living.

_{Reposted with permission from Decision Support in Medicine, LLC.}