Chapter 33-8: Chronic Obstructive Pulmonary Disease (COPD)

TEXTBOOK PRESENTATION

Presenting symptoms of COPD include progressive dyspnea, decreased exercise tolerance, cough, and sputum production. The onset is usually slow and progressive with occasional acute exacerbations. A long smoking history is present in almost all patients with COPD who live in industrialized countries.

DISEASE HIGHLIGHTS

1. COPD is defined in the WHO/NHLBI Global Strategy for the Diagnosis, Management, and Prevention of Chronic Obstructive Pulmonary Disease (GOLD) as a “disease state characterized by airflow limitation that is not fully reversible. The airflow limitation is usually both progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases.”

2. COPD should be considered in any patient with a smoking history who has pulmonary complaints. These complaints can be:

   1. Mild (smokers’ cough or lingering colds)

   2. Moderate (chronic cough, sputum production, and dyspnea)

   3. Severe (activity-limiting dyspnea with life-threatening exacerbations)

3. COPD can also be seen in patients without a smoking history but with significant exposure to secondhand smoke, occupational dust and chemicals and, especially in less developed countries, indoor air pollution from cooking stoves.

4. Because of the wide variation in disease course, it is impossible to give an average amount of exposure necessary to cause disease.

   1. Pulmonary symptoms usually develop after about 10 years of exposure.

   2. Airflow obstruction may develop later.

5. Emphysema and chronic bronchitis are currently being used less as descriptors of types of COPD.

   1. Emphysema is a pathologic term not accurately correlating with its general clinical usage.

   2. Chronic bronchitis is the presence of mucus production for most days of the month, 3 months of a year, for 2 successive years. This symptom does not suggest the airflow obstruction that causes the morbidity in COPD.

   3. Due to the overlap and lack of specificity of these 2 terms, COPD should be used as the diagnostic term.

6. The GOLD staging system is often used to classify patients based on their symptoms and level of risk of exacerbations. The system uses symptom severity and exacerbation risk to classify COPD.

   1. Symptoms, based on the Modified Medical Research Council (MMRC) dyspnea scale:

      1. Grade 0: “I only get breathless with strenuous exercise.”

      2. Grade 1: “I get short of breath when hurrying on level ground or walking up a slight hill.”

      3. Grade 2: “On level ground, I walk slower than people of the same age because of breathlessness, or have to stop for breath when walking at my own pace.”

      4. Grade 3: “I stop for breath after walking about 100 yards or after a few minutes on level ground.”

      5. Grade 4: “I am too breathless to leave the house or I am breathless when dressing.”

   2. Combined assessment

      1. Group A is at low risk and is less symptomatic: ≤ 1 exacerbation/year, and grade 0–1 symptoms

      2. Group B is at low risk but is more symptomatic: ≤ 1 exacerbation/year, and ≥ grade 2 symptoms

      3. Group C is at high risk but has few symptoms: ≥ 2 exacerbations/year, and grade 0–1 symptoms

      4. Group D ...