Chronic obstructive pulmonary disease (COPD), as defined by the World Health Organization (WHO), is a syndrome characterized by airflow obstruction that is not fully reversible with medical therapy.1,2 Most COPD patients are comprised of the 16–18 million Americans with chronic bronchitis and emphysema (Fig. 85-1). COPD is also a common comorbid condition for patients who present for thoracic or cardiac surgical evaluation. Coronary heart disease and lung cancer share with COPD the common risk factor of cigarette smoking. Thus many patients who present for surgical treatment of these conditions have physiologically relevant irreversible airflow obstruction.3,4 When evaluating patients with COPD for thoracic or cardiac surgery, it is important to assess the following:
Severity of obstructive lung disease, which is best done in the context of the current WHO staging guidelines5,6
Pulmonary risk for surgery, which is a function of disease, degree of airflow limitation, functional status, extent of compromise in gas exchange, age, and the specific surgical procedure
Baseline medical therapy, with the goal of optimizing the patient's pulmonary function prior to surgery
Smoking status because smoking cessation reduces the risk of postoperative complications7
Regions of lung affected in chronic bronchitis and emphysema.
Assessment of pulmonary risk in the thoracic surgery patient is discussed in Chapter 4 and will not be covered here. This chapter concerns the current WHO classification of disease severity for patients with COPD, recommendations for medical therapy in patients with varying degrees of airflow obstruction, recommendations for use of oxygen therapy in patients with chronic respiratory failure, recommendations for use of pulmonary rehabilitation (PR), the approach to smoking cessation in the COPD patient, and current guidelines for management of COPD exacerbations in the outpatient and perioperative settings. The surgical management of COPD is described in the ensuing chapters of this section (see Chaps. 86, 87, 88, and 89).
The recent Global Initiative for Chronic Obstructive Lung Disease consensus statement divides COPD into five stages depending on the extent of airflow limitation.5,6Stage 0 disease refers to patients with risk factors for the development of COPD (most commonly a more than 20 pack-year smoking history) and symptoms of chronic cough and phlegm but no evidence of airflow obstruction (FEV1 ≥ 80% predicted, FEV1/FVC ratio > 70%). These patients are “at risk” for the development of COPD, and a fraction ultimately will develop clinically significant airflow obstruction. Stage 1 disease refers to patients with very mild obstructive lung disease (FEV1 ≥ 80% predicted, FEV1/FVC ratio < 70%), the majority of whom have little, if any, functional compromise. Most patients with stage 1 disease remain undiagnosed, and their pulmonary symptoms have minimal impact on their functional status. Stage 2 disease refers to patients with mild to moderate airflow obstruction (80% ≥ FEV1 ≥ 50% predicted, FEV1/FVC ratio < 70%). At this stage, functional capacity may be somewhat compromised, and patients may experience dyspnea with exertion. However, most patients with stage 2 COPD do not seek medical attention for pulmonary symptoms and may escape diagnosis until presentation for a distinct medical problem such as newly diagnosed cardiac disease or lung cancer. Stage 3 disease refers to patients with moderate to severe airflow obstruction (50% ≥ FEV1...