Chronic obstructive pulmonary disease (COPD) is a functional diagnosis given to any pathological process that decreases the ability of the lungs and bronchi to perform their function of ventilation. It is an umbrella term that includes pulmonary emphysema and chronic bronchitis. COPD affects 12 million Americans, and it is estimated that 12 million more are undiagnosed. It is a common cause of death and disability in the United States.
Pulmonary emphysema (ICD-9:492) is the permanent enlargement of the air spaces beyond the terminal bronchioles resulting from destruction of alveolar walls. As a consequence of this destruction, the lungs slowly lose their normal elasticity. Air reaches the alveoli in the lungs during inhalation but may not be able to escape during exhalation. Evidence suggests that some forms of the emphysema may be hereditary. In rare instances, emphysema is associated with a deficiency of a1-antitrypsin, a protein that plays a role in maintaining lung elasticity.
FIGURE. (A) Lung tissue with normal alveoli. (B) Lung tissue with emphysema. (From Scanlon, VC, and Sanders, T: Essentials of Anatomy and Physiology, ed 5. FA Davis, Philadelphia, 2007, p 352, with permission.)
Chronic bronchitis (ICD-9:491) is inflammation of the bronchial mucous membranes causing the lining to thicken and produce a chronically productive cough. It is characterized by hypertrophy and hyperplasia of bronchial mucous glands, damage to the microscopic hairlike extensions of cells lining the interior of the bronchi (bronchial cilia), and narrowing of the bronchial airways. The passageways become clogged with mucus.
Other diseases that may lead to a diagnosis of COPD include chronic asthma, bronchiectasis, silicosis, and pulmonary tuberculosis. Smoking, prolonged exposure to polluted air, respiratory infections, and allergies are predisposing factors in this disease. Occupational risk factors include exposure to textile dust fibers and certain petrochemicals.
Signs and Symptoms
COPD tends to develop insidiously, so no symptoms may be present initially until lung damage has already occurred. Later, a person may tire easily while exercising or doing strenuous work. The chest tightens and dyspnea on minimal exertion then develops. Chronic cough, chest tightness, and increased mucus production are exhibited. A chronic cough with sputum production is the classic symptom of chronic bronchitis. A client with chronic bronchitis may have only a minimal increase in airway resistance. As the disease progresses, the increase in airway resistance becomes greater. Weight gain due to edema and cyanosis, tachypnea, and wheezing may also be evident.
A characteristic “barrel chest” is often seen in pulmonary emphysema. The appearance of the barrel chest is the result of lungs chronically overinflated with air causing the rib cage to stay partially expanded.
Two identifiers common in COPD are “blue bloater” and “pink puffer.” A blue bloater describes a person with chronic bronchitis whose body responds to the increased obstruction by decreasing ventilation and increasing cardiac output. This leads to hypoxemia (oxygen deficiency in the blood) and polycythemia (excessive red blood cells). Together with retention of carbon dioxide, individuals show signs of cardiac failure and are described as blue bloaters.
A pink puffer describes a person with emphysema who has the decreased inability to oxygenate the blood. The body compensates with lower cardiac output and hyperventilation, causing a reddish complexion and a “puffing” appearance when breathing.
A physical examination, chest x-ray, pulmonary function tests, arterial blood gases, sputum analysis, and CT scan are the procedures used to diagnose COPD, chronic pulmonary emphysema, and chronic bronchitis.
Treatment is aimed at preventing further lung damage, relieving symptoms, and preventing complications. Persons diagnosed with COPD should be advised not to smoke. Bronchodilators may be used to open the air passages in the lungs, inhaled corticosteroid medications can reduce airway inflammation and help make breathing easier, and antibiotics may be prescribed in the event of respiratory infections. Administration of oxygen may eventually be necessary. Diuretics may be required. Surgery is an option for some. Lung volume reduction surgery removes small wedges of damaged lung tissue, creating extra space in the chest cavity. A single lung transplant may work for certain people with severe emphysema. Either surgery, however, may not prolong life and has a number of complicated risks.
Comprehensive pulmonary rehabilitation may be able to improve quality of life. The combination of education, exercise, nutrition, and counseling likely comes from physical therapists, respiratory therapists, physical fitness specialists, and dietitians who create a program for individual client needs.
People with COPD need proper nutrition. So much energy is spent on breathing that ventilatory muscles can require up to 10 times the calories required of a healthy person’s muscles. The client should eat foods from the basic food groups and limit salt and caffeine intake. If the client is using oxygen, the cannula should be worn while eating. Proper diet will help clients feel better and enable them to better fight infection.
It is essential for clients to avoid cigarettes, cigarette smoke, dust, air pollution, and workrelated fumes. Advise clients to avoid excessive heat, cold, and high altitudes.
The prognosis for COPD is difficult. The disease cannot be cured, and lost pulmonary function cannot be restored. However, COPD can be managed, controlled, and slowed. The degree of disability produced by COPD varies but tends to increase with time. The clinical development of COPD is described in three stages: (1) lung function is 50% or better, (2) lung function is 35% to 49% with a significant impact on health, and (3) lung function is less than 35% with a profound impact on health. Progressive diminution of pulmonary function leading to respiratory failure accounts for most deaths.
Prevention includes not smoking, especially if other family members have a history of the disease. Early diagnosis is helpful. Periodic physical examinations to evaluate the development of COPD are recommended. Such a chronic disease often calls for evaluation from a pulmonary specialist.