ACSM'S Health & Fitness Journal:
Shelby Scott, M.D., FACSM, is part-time faculty at Natividad Medical Center in Salinas, CA and associate clinical faculty at UCSF School of Medicine. She practices Family Practice and Sports Medicine in the Santa Cruz area of California.
Chronic obstructive lung disease (COPD) is a condition that limits airflow in the lungs and causes difficulty in breathing. It is separate from asthma and chronic bronchitis, but people with those chronic lung diseases may have or develop COPD. Ninety percent of the cases are related to tobacco smoking, but there are other genetic and environmental factors. Some people lack an enzyme, alfa-1-antitrypsin, making them very susceptible to COPD (1). Alfa-1-antitrypsin is made in the liver and protects lung tissue. One percent of all cases of COPD are caused by a severe deficiency of this enzyme, and the lung disease is preventable with a liver transplant. An estimated 25 million Americans carry the defective gene. Another factor that increases the risk of COPD is environmental or occupational exposure to dusts or chemical irritants.
The COPD is a major health problem in the United States. In 2003, approximately 122,283 people died of COPD making it the fourth leading cause of death in America (2). It is predicted to be the third leading cause of death globally by the year 2020 (3). More women than men have died of this disease since 1999, and (2-4) the economic impact of COPD is tremendous. The National Heart, Lung, and Blood Institute estimates that the United States annually spends 20.9 billion in direct health care expenditures and 16.3 billion in indirect morbidity and mortality costs (2). A recent survey of people with lung disease predicts more than twice as many people with COPD than are actually given the proper diagnosis (4). This means that the impact of the disease spectrum of COPD is worse than what is actually documented.
Obstructive airway disease is very disabling. People are often very limited by their shortness of breath, often reporting difficulty even while performing daily activities by the time of diagnosis. Symptoms of chronic cough and wheezing with exertion present in the 40s (Table 1). Often, the patients' partners are more bothered by the symptoms than the patient. The next decade holds recurrent or chronic respiratory tract infections, often resulting in visits to the physician. During an infection or exacerbation of COPD, patients complain of production of purulent-or foul appearing-sputum, increased cough, wheezing without exertion, and sometimes fever. Because early COPD responds to albuterol, patients are often misdiagnosed as having asthma. More severe disease is present in the 60s with more noticeable chronic cough and sputum production, dyspnea on exertion, fear of physical activity, shortness of breath upon lying down, and more frequent exacerbation of symptoms. For some people with COPD, the thought of walking to the store or the mailbox makes them anxious. In response to this anxiety, their work of breathing increases, leading to lactic acid production that needs to be blown off by the lungs. Hence, the respiratory rate increases, leading to a sensation of shortness of breath and increased anxiety (5-7).
The mainstay of treatment for COPD is bronchodilators (Table 2). For acute exacerbations, oral steroids help to lessen the secretions and sputum production. Some people respond very favorably to steroids and stay on them for long-term management. Inhaled steroids are preferred over oral for long-term use. People with COPD are more prone to infection, so it is very important to immunize against influenza and pneumonia. Some people require oxygen either at bedtime or with physical activity. Besides increasing the oxygen available to tissues, supplemental oxygen reduces the anxiety of breathing. A fan blowing air across the face does the same.
Another nonpharmaceutical intervention for COPD is pulmonary rehabilitation (5-7). Pulmonary rehabilitation is a multidisciplinary approach aimed at decreasing symptoms and hospitalizations for COPD. The programs consist of exercise conditioning, smoking cessation, breathing retraining, disease education (including nutritional information), and psychosocial support. Because any amount of physical exertion increases shortness of breath, patients decrease their physical activity and can develop symptoms of anxiety when thinking about activity as previously mentioned. This leads to a vicious cycle of deconditioning resulting in shortness of breath and symptoms at lower levels of activity. By strengthening any muscle group, the body will produce less lactic acid at the same level of activity. This leads to a lower respiratory drive and less anxiety. As people become more confident, they can increase their conditioning and participation in their usual daily activities or social functions. A small increase in physical capacity results in marked improvement in quality of life (5, 6).
Despite the many treatment options available for COPD, prevention is more important. Smoking cessation can reverse obstructive changes and slows the loss of lung function. Lung function naturally decreases with age, but smoking accelerates this process two to five fold. The disease process of COPD decreases within the first year after the patient stops smoking, and subsequent decline in lung function follows that of a nonsmoker. For people with alfa-1-antitrypsin deficiency, a liver transplant at an early age can prevent lung disease. Blood or oral mucosa samples can determine carrier status and severity of illness. Gene therapy is being developed as well. People who work in construction, agriculture, or mining should always use the proper masks and ventilation devices.
2. American Lung Association. Trends in chronic bronchitis and emphysema: Morbidity and mortality. American Lung Association Epidemiology & Statistics Unit Research and Program Services, July 2006. Available at: http://www.lungusa.org/site/pp.asp?c=dvLuk9O0E&b=35020
. Accessed November 17, 2006.
3. Dewar, M. and W. Curry. Chronic obstructive pulmonary disease: diagnostic considerations. American Family Physician
73(4):669-676, 677-678, 2006.
4. National Center for Health Statistics, National Health Interview Survey data, 1982-1996, 1997-2004. Available at: http://www.cdc.gov/nchs/nhis.htm
. Accessed November 17, 2006.