Chronic Obstructive Pulmonary Disease
Definition
Chronic obstructive pulmonary disease (COPD), also called chronic obstructive lung disease, is a term that is used for two closely related diseases of the respiratory system: chronic bronchitis and emphysema. In many cases these diseases occur together, although there may be more symptoms of one than the other. Most patients with these diseases have a long history of heavy cigarette smoking.
Description
COPD gets gradually worse over time. At first, there may be only a mild shortness of breath and occasional coughing. Then a chronic cough develops with clear, colorless sputum. As the disease progresses, the cough becomes more frequent and more effort is needed to get air into and out of the lungs. In later stages of the disease, the heart may be affected. Eventually death occurs when the function of the lungs and heart is no longer adequate to deliver oxygen to the body's organs and tissues. COPD often develops in people at the height of their productive years, disabling them with constant shortness of breath. It destroys their ability to earn a living, causes frequent use of the health care system, and disrupts the lives of the victims' family members for as long as 20 years before death occurs. Chronic bronchitis, one of the two major disease of the lung grouped under COPD, is diagnosed when a patient has excessive airway mucus secretion leading to a persistent, productive cough. An individual is considered to have chronic bronchitis if cough and sputum are present on most days for a minimum of 3 months for at least 2 successive years or for 6 months during 1 year. In chronic bronchitis, there may also be narrowing of the large and small airways, making it more difficult to move air in and out of the lungs. In emphysema, there is a permanent destruction of the alveoli, the tiny elastic air sacs of the lung, because of irreversible destruction of a protein in the lung called elastin that is important for maintaining the strength of the alveolar walls. The loss of elastin also causes collapse or narrowing of the smallest air passages, called bronchioles, which in turn limits airflow out of the lung.
Causes
Cigarette smoking is the most important risk factor for COPD, both in developing it to begin with and making it worse if COPD is present. Other risk factors include age, heredity, exposure to air pollution at work and in the environment, and a history of childhood respiratory infections. Living in low socioeconomic conditions also seems to be a contributing factor. COPD is the fifth leading cause of death in the U.S.
Symptoms
Daily morning cough is the earliest symptom of COPD. During a cold or other acute respiratory tract infection, the coughing may be much more noticeable and the sputum often turns yellow or greenish. Periods of wheezing are likely to occur especially during or after colds or other respiratory tract infections. Shortness of breath on exertion develops later and progressively becomes more pronounced with severe episodes of breathlessness (dyspnea) occurring after even modest activity. A typical course of COPD might proceed as follows. For a period of about 10 years after cigarette smoking begins, symptoms are usually not very noticeable. After this, the patient generally starts developing a chronic cough with the production of a small amount of sputum. It is unusual to develop shortness of breath during exertion below the age of 40, after which it becomes more common and may be well developed by the age of 50. However, although all COPD patients have these symptoms, not all cigarette smokers develop a notable cough and sputum production, or shortness of breath. Most patients with COPD have some degree of reversible airway obstruction. It is therefore likely that, at first, treatment will lead to some improvement or stability in lung function. But as COPD progresses, almost all signs and symptoms except cough and sputum production tend to show a gradual worsening. Repeated bouts of increased cough and sputum production disable most patients, and recovery from coughing attacks may take a long time. Patients with severe lung damage sleep in a semi-sitting position because they are unable to breathe when they lie down. They often complain that they awaken during the night feeling "choked up," and they need to sit up to cough.
Treatment
Although there is no cure for COPD, the disease can be prevented. And, in almost all cases the disabling symptoms can be reduced. Because cigarette smoking is the most important cause of COPD, not smoking almost always prevents COPD from developing, and quitting smoking slows the disease process. Home oxygen therapy can improve survival in patients with advanced COPD who have hypoxemia - low blood oxygen levels. Many oxygen sources are available for home use; these include tanks of compressed gaseous oxygen or liquid oxygen, or devices that concentrate oxygen from room air. Medications frequently prescribed for COPD patients are bronchodilators that help open narrowed airways. The three main categories of bronchodilators are sympathomimetics (isoproterenol, albuterol), parasympathomimetics (atropine, ipratropium bromide), and methylxanthines (theophylline and its derivatives). Corticosteroids or steroids lessen inflammation of the airways and are sometimes used if airway obstruction cannot be kept under control by bronchodilators. Antibiotics can be used to fight infection, while expectorants help loosen and expel mucus secretions from the airways. Other drugs sometimes taken by patients with COPD include tranquilizers, painkillers, cough suppressants and sleeping pills. Antibiotics have been used for many decades to treat patients with exacerbations of chronic bronchitis, but the efficacy is unclear. Clinical trials examining the issue have produced mixed results, making it difficult to draw conclusions.
Prevention
Prevention of most cases of COPD is simple: DON'T SMOKE.
Questions
Is there significant airway obstruction? Is this bronchitis or emphysema, or both? Would oxygen therapy help? Is the use of bronchodilators indicated? Can steroids alleviate the symptoms? Will the problem get worse?
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