Chronic Obstructive Pulmonary Disease (COPD)

Key Features

Essentials of Diagnosis

• History of cigarette smoking or other chronic inhalational exposure

• Chronic cough, dyspnea, and sputum production

• Rhonchi, decreased intensity of breath sounds, and prolonged expiration on physical examination

• Airflow limitation on pulmonary function testing

General Considerations

• Airflow obstruction due to chronic bronchitis or emphysema; most patients have features of both

• Obstruction

  • Is progressive

  • May be accompanied by airway hyperreactivity

  • May be partially reversible

• Chronic bronchitis is characterized by sputum production with productive cough for 3 months or more in at least 2 consecutive years

• Emphysema is abnormal enlargement of air spaces distal to terminal bronchiole, with destruction of bronchial walls without fibrosis

• Cigarette smoking is the most important cause

  • About 80% of patients have had a significant exposure to tobacco smoke

• Air pollution, airway infection, environmental factors, and allergy have been implicated in chronic bronchitis

• α₁-Antiprotease deficiency has been implicated in emphysema

Clinical Findings

Symptoms and Signs

• Presentation

  • Usually at 40–50 years of age

  • Cough

  • Sputum production

  • Shortness of breath

• Dyspnea initially occurs only with heavy exertion, progressing to symptoms at rest in severe disease

• Exacerbation of symptoms beyond normal day-to-day variation, often including increased dyspnea, an increased frequency or severity of cough, increased sputum volume, or change in sputum character

• Infections (viral more commonly than bacterial) precede exacerbations in most patients

• Late-stage COPD characterized by

  • Hypoxemia

  • Pneumonia

  • Pulmonary hypertension

  • Cor pulmonale

  • Respiratory failure

• Clinical findings may be absent early

• Patients are often dichotomized as "pink puffers" or "blue bloaters" depending on whether emphysema or chronic bronchitis predominates (Table 9–6)