Emphysema occurs when the alveoli lose their ability to stretch.
Emphysema is a form of lung disease in which the walls of the air sacs (alveoli) lose the ability to stretch. As elasticity is lost, air is trapped in the air sacs and impairs the exchange of oxygen and carbon dioxide. Obstruction of airflow also results if the airways leading to the alveoli collapse. Damage to the air sacs is not reversible and permanent holes in lung tissue are the result. As this damage occurs, the lungs transfer less oxygen to the blood stream resulting in shortness of breath. The lack of elasticity makes it difficult to keep the airways open and exhaling requires more energy. Emphysema occurs very gradually, usually preceded by years of exposure to cigarette smoke. Since the progression of the disease is so gradual, symptoms may not occur until after irreversible damage has occurred. Medications are used to alleviate symptoms and lung surgery may also be necessary.
Cigarette smoking is the overwhelming cause of emphysema. When tobacco smoke infiltrates the lungs, the airways and alveoli become inflamed and lose their elasticity. One in seven smokers will develop chronic obstructive pulmonary disease (COPD). COPD refers to patients who have both emphysema and chronic bronchitis. According to the National Heart, Lung, and Blood Institute, more than 12 million Americans have COPD and it is the fourth leading cause of death.
Another cause of emphysema is a deficiency in alpha-1anitrypsin (AAT). AAT is a protein that protects the lungs from damage, and a deficiency increases the risk of emphysema. An estimated 100,000 Americans were born with this deficiency, and 25 million may pass on a single deficient gene to their children. According to the National Institutes of Health, approximately 75 percent of those with a severe deficiency will develop emphysema, and smoking increases the severity in AAT-deficient adults.
According to the Mayo Clinic, the primary symptoms of emphysema are shortness of breath and an inability to exercise without feeling breathless. Anxiety, fatigue and unintentional weight loss are other possible symptoms. The patient may also appear barrel-chested or have bluish nail beds. If the patient also has chronic bronchitis, thick mucus forms in the airways.
A physical examination can often detect prolonged exhalation or wheezing. Further tests, such as a chest x-ray, and arterial blood gases help confirm the diagnosis. Pulmonary function tests can even detect emphysema before symptoms are experienced. These tests measure the amount of air that the lungs hold and the flow of air in and out. A pulse oximetry test measures the amount of oxygen in the blood to determine whether supplemental oxygen is required. A computerized tomography (CT) scan can detect emphysema sooner that a chest x-ray; however, it cannot determine the severity of the disease as well as a pulmonary function test. Since emphysema is a serious disease that damages the lungs and possibly the heart, a physician should be consulted at the first sign of symptoms.
Treatment of emphysema is meant to relieve symptoms and prevent further damage to the lungs so that patients may live more comfortably. Smoking cessation is the most important factor in preventing further damage and maintaining healthy lungs. Bronchodilators can be prescribed to open airways as well as antibiotics for accompanying respiratory infections. Other medications used to treat emphysema include diuretics and corticosteroids, and physicians recommend vaccines to prevent flu and pneumonia. Breathing exercises as a part of a pulmonary rehabilitation program help strengthen the muscles used for breathing and improve tolerance for exercise. Low-flow oxygen may be used during the night or during periods of exertion.
In severe cases, a lung transplant can be effective. Another surgical option for select patients is lung volume reduction surgery (LVRS). During this procedure, portions of the damaged lung are removed, allowing the normal portions of the lung to expand fully and work better. Short-term results of this surgery are promising, but there is a risk of death for patients suffering from severe forms of emphysema. Also, high-risk patients may find that the Centers for Medicare and Medicaid Services, do not cover LVRS.
Since the majority of people who suffer from emphysema are smokers, not smoking reduces the risk of getting the disease as well as decreases the progression of the disease in those who have it. In addition, limiting exposure to secondhand smoke and wearing a dust mask when exposed to chemical fumes and dust reduces the risk. Minimizing exposure to air pollution reduces symptoms of emphysema, and vaccinations against flu and pneumonia help in preventing aggravated symptoms due to illness. Maintaining good health through nutrition, exercise and adequate sleep builds resistance to infections.