Chronic obstructive pulmonary disease (COPD) is defined by the Global Initiative for Chronic Obstructive Lung Disease (GOLD)1 as persistent, usually progressive, airflow limitation associated with an enhanced inflammatory response, generally in response to noxious stimuli, such as cigarette smoking. COPD is one of the few major chronic, noninfectious diseases with a rising burden; it is now the third leading cause of death in the United States.2 Worldwide, an increasing prevalence of cigarette smoking, exposure to substances such as biomass fuel, a reduction in other causes of early mortality, and an aging population have led to an increase in the global burden of COPD; from 1990 to 2015, the prevalence of COPD increased by more than 40%.3
COPD is a common comorbid condition in patients presenting for thoracic surgical evaluation (Fig. 101-1), in large part due to the shared risk factors of age and cigarette smoking. In addition, increasing evidence suggests that COPD itself may be a risk factor for lung cancer4 and cardiovascular disease.5 COPD is commonly underdiagnosed.6 Furthermore, the presence of COPD has substantial impact on thoracic surgical outcomes.7
Regions of lung affected in chronic bronchitis and emphysema. These conditions are present in the majority of patients with COPD in the United States.
This chapter reviews some of the diagnostic and management considerations of COPD related to thoracic surgery, specifically:
Diagnosis and severity of COPD
Management of stable COPD, with the goal of identifying comorbidities and optimizing pulmonary function prior to surgery
Management of exacerbations
Assessment of preoperative pulmonary risk is covered in Chapter 4. Surgical management of COPD is discussed in the ensuing Chapters 102 to 105.
DIAGNOSIS AND SEVERITY OF COPD
The diagnosis of COPD should be considered in any patient who has persistent dyspnea, chronic cough or sputum, and/or a history of exposure to risk factors for disease (generally at least 10–20 pack-years of cigarette smoking).1 The GOLD definition of COPD requires spirometry: airflow limitation is identified by a reduced postbronchodilator forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC) ratio of less than 0.7. The use of the fixed criterion of 0.7 for the ratio of FEV1/FVC is chosen for simplicity but has been criticized because the FEV1/FVC normally declines with age.8 However, older subjects potentially misclassified as having obstruction by the use of this single value have been shown to have worse outcomes, arguing that the use of a fixed ratio is acceptable.9,10
Despite the simplicity of making a diagnosis of COPD based on spirometry and a fixed-ratio definition of airflow obstruction, underdiagnosis is common because many patients with COPD are asymptomatic ...