Emphysema

Definition

Emphysema is a chronic respiratory disease where there is over-inflation of the air sacs (alveoli) in the lungs, causing a decrease in lung function, and often, breathlessness.

Description

Emphysema is the most common cause of death from respiratory disease in the United States, and is the fourth most common cause of death overall. There are 1.8 million Americans with the disease, which ranks fifteenth among chronic conditions that cause limitations of activity. The disease is usually caused by smoking, but a small number of cases are caused by an inherited defect.

Normally functioning lungs are elastic, efficiently expanding and recoiling as air passes freely through the bronchus to the alveoli, where oxygen is moved into the blood and carbon dioxide is filtered out. When a person inhales cigarette smoke or certain other irritants, his or her immune system responds by releasing substances that are meant to defend the lungs against the smoke. These substances can also attack the cells of the lungs, but the body normally inhibits such action with the release of other substances. In smokers and those with the inherited defect, however, no such prevention occurs and the lung tissue is damaged in such a way that it loses its elasticity. The small passageways (bronchioles) leading to the alveoli collapse, trapping air within the alveoli. The alveoli, unable to recoil efficiently and move the air out, over expand and rupture. As the disease progresses, coughing and shortness of breath occur. In the later stages, the lungs cannot supply enough oxygen to the blood. Emphysema often occurs with other respiratory diseases, particularly chronic bronchitis. These two diseases are often referred to as one disorder called chronic obstructive pulmonary disease (COPD).

Emphysema is most common among people aged 50 and older. Those with inherited emphysema may experience the onset as early as their thirties or forties. Men are more likely than women to develop emphysema, but female cases are increasing as the number of female smokers rises.

Causes and symptoms

Heavy cigarette smoking causes about 80-90% of all emphysema cases. However a few cases are the result of an inherited deficiency of a substance called alpha-1-antitrypsin (AAT). The number of Americans with this deficiency is relatively small, probably no greater than 70,000. Pipe, cigar, and marijuana smoking can also damage the lungs. While a person may be less likely to inhale cigar and pipe smoke, these types of smoke can also impair lung function. Marijuana smoke may be even more damaging because it is inhaled deeply and held in by the smoker.

The symptoms of emphysema develop gradually over many years. It is a common occurrence for many emphysema patients to have lost over half of their functioning lung tissue before they become aware that something is wrong. Shortness of breath, a chronic mild cough (which may be productive of large amounts of dark, thick sputum, and often dismissed as "smoker's cough"), and sometimes weight loss are associated with emphysema. Initially, a patient may only notice shortness of breath when he or she is exercising. However, as the disease progresses, it will occur with less exertion or no exertion at all. Emphysema patients may also develop an enlarged, or "barrel,", chest. Other symptoms may be skipped breaths, difficulty sleeping, morning headaches, increased difficulty breathing while lying down, chronic fatigue, and swelling of the feet, ankles, or legs. Those with emphysema are at risk for a variety of other complications resulting from weakened lung function, including pneumonia.

Diagnosis

A variety of pulmonary function tests may be ordered. In the early stages of emphysema, the only result may be dysfunction of the small airways. Patients with emphysema may show an increase in the total amount of air that is in the lungs (total lung capacity), but a decrease in the amount of air that can be breathed out after taking a deep breath (vital capacity). With severe emphysema, vital capacity is substantially below normal. Spirometry, a procedure that measures air flow and lung volume, helps in the diagnosis of emphysema.

A chest x ray is often ordered to aid in the diagnosis of emphysema, though patients in the early stages of the disease may have normal findings. Abnormal findings on the chest x ray include over-inflation of the lungs and an abnormally increased chest diameter. The diaphragm may appear depressed or flattened. In addition, patients with advanced emphysema may show a smaller or vertical heart. The physician may observe blisters in the lungs and bulging of the accessory muscles of the respiratory system. Late in the disease, an EKG will show signs of right ventricular failure in the heart and increased hemoglobin due to lower levels of oxygen in the patient's blood.

Treatment

Treatment methods for emphysema do not cure or reverse the damage to the lungs. However, they may slow the progression of the disease, relieve symptoms, and help control possibly fatal complications. The first step in treatment for smokers is to quit, so as to prevent any further deterioration of breathing ability. Smoking cessation programs may be effective. Consistent encouragement along with the help of health care professionals as well as family and friends can help increase the success rate of someone attempting to quit.

If the patient and the health care team develop and maintain a complete program of respiratory care, disability can be decreased, acute episodes of illness may be prevented, and the number of hospitalizations reduced. However, only quitting smoking has been shown to slow down the progression of the disease, and among all other treatments, only oxygen therapy has shown an increase in the survival rate.

Home oxygen therapy may improve the survival times in those patients with advanced emphysema who also have low blood oxygen levels. It may improve the patient's tolerance of exercise, as well as improve their performance in certain aspects of brain function and muscle coordination. The functioning of the heart may also improve with an increased concentration of oxygen in the blood. Oxygen may also decrease insomnia and headaches. Some patients may only receive oxygen at night, but studies have illustrated that it is most effective when administered at least 18, but preferably 24 hours per day. Portable oxygen tanks prescribed to patients carry a limited supply and must be refilled on a regular basis by a home health provider. Medicare and most insurance companies cover a large proportion of the cost of home oxygen therapy. Patients should be instructed regarding special safety issues involving the transport and presence of oxygen in the home.

A variety of medications may be used in the treatment of emphysema. Usually the patient responds best to a combination of medicines, rather than one single drug.

Bronchodilators are sometimes used to help alleviate the patient's symptoms by relaxing and opening the airways. They can be inhaled, taken by mouth, or injected. Another category of medication often used is corticosteroids or steroids. These help to decrease the inflammation of the airway walls. They are occasionally used if bronchodilators are ineffective in preventing airway obstruction. Some patients' lung function improves with corticosteroids, and inhaled steroids may be beneficial to patients with few side effects. A variety of antibiotics are frequently given at the first sign of a respiratory infection, such as increased amounts of sputum, or if there has been a change in the color of the sputum. Expectorants can help to loosen respiratory secretions, enabling the patient to more easily expel them from the airways.

Many of the medications prescribed involve the use of a metered dose inhaler (MDI) that may require special instruction to be used correctly. MDIs are a convenient and safe method of delivering medication to the lungs. However, if they are used incorrectly the medication will not get to the right place. Proper technique is essential for the medication to be effective.

For some patients, surgical treatment may be the best option. Lung volume reduction surgery is a surgical procedure in which the most diseased parts of the lung are removed to enable the remaining lung and breathing muscles to work more efficiently. Preliminary studies suggest improved survival rates and better functioning with the surgery. Another surgical procedure used for emphysema patients is lung transplantation. Transplantation may involve one or both lungs. However, it is a risky and expensive procedure, and donor organs may not be available.

For those patients with advanced emphysema, keeping the air passages reasonably clear of secretions can prove difficult. Some common methods for mobilizing and removing secretions include:

• Postural drainage. This helps to remove secretions from the airways. The patient lies in a position that allows gravity to aid in draining different parts of the lung. This is often done after the patient inhales an aerosol medication. The basic position involves the patient lying on the bed with his chest and head over the side and the forearms resting on the floor.
• Chest percussion. This technique involves lightly clapping the back and chest, and may help to loosen thick secretions.
• Coughing and deep breathing. These techniques may aid the patient in bringing up secretions.
• Aerosol treatments. These treatments may involve solutions of saline, often mixed with a bronchodilator, which are then inhaled as an aerosol. The aerosols thin and loosen secretions. A treatment normally takes 10 to 15 minutes, and is given three or four times a day.

Patients with COPD can learn to perform a variety of self-help measures that may help improve their symptoms and their ability to participate in everyday activities. These measures include:

• Avoiding any exposure to dusts and fumes.
• Avoiding air pollution, including the cigarette smoke of others.
• Avoiding other people who have infections like the cold or flu. Get a pneumonia vaccination and a yearly flu shot.
• Drinking plenty of fluids. This helps to loosen respiratory secretions so they can be brought up more easily through coughing.
• Avoiding extreme temperatures of heat or cold. Also avoiding high altitudes. (Special precautions can be taken that may enable the emphysema patient to fly on a plane.)
• Maintaining adequate nutritional intake. Normally a high protein diet taken in many small feedings is recommended.

Alternative treatment

Many patients are interested in whether any alternative treatments for emphysema are available. Some practitioners recommend supplements of antioxidant nutrients. There have also been some studies indicating a correlation between a low Vitamin A levels and COPD, with suggestions that supplements of vitamin A might be beneficial. Aromatherapists have used essential oils like eucalyptus, lavender, pine, and rosemary to help relieve nasal congestion and make breathing easier. The herb elecampane may act as an expectorant to help patients clear mucus from the lungs. The patient should discuss these remedies with their health care practitioner prior to trying them, as some may interact with the more traditional treatments that are already being used.

Prognosis

Emphysema is a serious and chronic disease that cannot be reversed. If detected early, the effects and progression can be slowed, particularly if the patient stops smoking immediately. Complications of emphysema include higher risks for pneumonia and acute bronchitis. Overall, the prognosis for patients with emphysema is poor, with a survival rate for all those with COPD of four years, and even less for emphysema. However, individual cases vary and many patients can live much longer with supplemental oxygen and other treatment measures.

Prevention

The best way to prevent emphysema is to avoid smoking. Even patients with inherited emphysema should avoid smoking, as it especially worsens the onset and severity. If patients quit smoking as soon as evidence of small airway obstruction begins, they can significantly improve their prognosis.

Key terms

Alveoli — Small cells or cavities. In the lungs, these are air sacs where oxygen enters the blood and carbon dioxide is filtered out.

Pulmonary — Related to or associated with the lungs.

Resources

Books

Beers, Mark H., and Robert Berkow, editors. The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck and Company, Inc., 2004.

Periodicals

"Data Mounting on Merits of Lung Volume ReductionSurgery." Family Practice News February 15, 2001: 5.

Lewis, Laurie. "Optimal Treatment for COPD." PatientCare May 30, 2000: 60.

Organizations

American Lung Association. 1740 Broadway New York, NY 10019. (212) 315-8700. http://www.lungusa.org.

National Emphysema Foundation. 15 Stevens St. Norwalk, CT 06856. http://www.emphysemafoundation.org.

National Heart, Lung and Blood Institute. http://www.nhlbi.nih.gov.

Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.

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emphysema /em·phy·se·ma/ (em″fĭ-se´mah)

1. a pathologic accumulation of air in tissues or organs.

2. pulmonary e.emphysem´atous

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atrophic emphysema  senile e.

bullous emphysema  single or multiple large cystic alveolar dilatations of lung tissue.

centriacinar emphysema , centrilobular emphysema focal dilatations of respiratory bronchioles rather than alveoli, throughout the lung among normal lung tissue.

congenital lobar emphysema  overinflation of a lung, usually in early life in one of the upper lobes, with respiratory distress.

hypoplastic emphysema  pulmonary emphysema due to a developmental anomaly, with fewer and abnormally large alveoli.

infantile lobar emphysema  congenital lobar e.

interlobular emphysema  air in the septa between lung lobules.

interstitial emphysema  air in the peribronchial and interstitial tissues of the lungs.

intestinal emphysema  pneumatosis cystoides intestinalis.

mediastinal emphysema  pneumomediastinum.

obstructive emphysema  that associated with partial bronchial obstruction that interferes with exhalation.

panacinar emphysema , panlobular emphysema a type characterized by enlargement of air spaces throughout the acini.

pulmonary emphysema  abnormal increase in size of lung air spaces distal to the terminal bronchioles.

pulmonary interstitial emphysema  (PIE) a condition seen mostly in premature infants, in which air leaks from lung alveoli into interstitial spaces, often because of underlying lung disease or use of mechanical ventilation.

senile emphysema  overdistention and stretching of lung tissues due to atrophic changes.

subcutaneous emphysema  air or gas in subcutaneous tissues, usually caused by intrathoracic injury.

surgical emphysema  subcutaneous emphysema following surgery.

vesicular emphysema  panacinar e.

Dorland's Medical Dictionary for Health Consumers. © 2007 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

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emphysema

[em′fəsē′mə]

Etymology: Gk, en + physema, a blowing

an abnormal condition of the pulmonary system, characterized by overinflation and destructive changes in alveolar walls. It results in a loss of lung elasticity and decreased gas exchange. When emphysema occurs early in life, it is usually related to a rare genetic deficiency of serum alpha-1-antitrypsin, which inactivates the enzymes leukocyte collagenase and elastase. More common causes are air pollution and cigarette smoking. Acute emphysema may be caused by the rupture of alveoli during severe respiratory efforts, as may occur in acute bronchopneumonia, suffocation, whooping cough, and, occasionally, labor. Patients with chronic emphysema may also have a component of chronic bronchitis. Emphysema also occurs after asthma or tuberculosis, conditions in which the lungs are overstretched until the elastic fibers of the alveolar walls are destroyed. In old age the alveolar membranes atrophy and may collapse, producing large, air-filled spaces and a decreased total surface area of the pulmonary membranes. There are three primary types: centriacinar emphysema, distal acinar emphysema, and panacinar emphysema. -emphysematous, adj.

observations The patient may have dyspnea on exertion or at rest, cough, orthopnea, unequal chest expansion, tachypnea, tachycardia, diminished breath sounds caused by air trapping, or, atypically, an elevated temperature and breath sounds if there is an infection. Anxiety, increased PaCO₂, restlessness, confusion, weakness, anorexia, hypoxemia, and respiratory failure are common in advanced cases. Chronic emphysema is characterized by increased anterior-posterior chest diameter secondary to hyperinflation and air trapping and use of accessory muscles.

interventions The primary treatment consists of breathing exercises, oxygen administration, and avoiding infection. The airway is kept open, and oxygen is administered to maintain an arterial oxygen saturation of 92%. Bronchodilators, antibiotics, expectorants when bronchitis is also present, methylxanthines, and corticosteroids may be prescribed. Sedation is to be avoided because sedatives depress respiratory function.

nursing considerations The patient is taught breathing exercises and encouraged to drink between 2 and 3 L of fluids daily, if not contraindicated by cardiac function. Activity is encouraged to the limit of the patient's tolerance. Fatigue, constipation, and upper respiratory tract infection and irritation are to be avoided. Mechanical ventilation and oxygen therapy may be prescribed for use at home. The patient is taught the adverse role that smoking plays in the disease and is encouraged to stop smoking.

Mosby's Medical Dictionary, 8th edition. © 2009, Elsevier.

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emphysema

a pathological accumulation of air in tissues. The air may derive from a skin laceration and be drawn in by the movements of muscles. A discontinuity of the tracheal mucosa is a common cause, either by way of laceration or ulceration. Extension from a pulmonary lesion is also common. The syndrome resulting depends on the location of the air. See also pulmonary emphysema and subcutaneous emphysema (below).

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acute bovine pulmonary emphysema

see atypical interstitial pneumonia.

alveolar emphysema

see pulmonary emphysema (below).

bullous emphysema

emphysema in which bullae form in areas of lung tissue so that these areas do not contribute to respiration.

conjunctival emphysema

may occur after head trauma which permits escape of air from the paranasal sinuses.

fetal emphysema

see emphysematous/putrescent fetus.

generalized emphysema

widespread distribution of air, including subcutaneous tissues, seen with pneumomediastinum.

hypoplastic emphysema

pulmonary emphysema due to a developmental abnormality, resulting in a reduced number of alveoli, which are abnormally large.

interlobular emphysema

accumulation of air in the septa between lobules of the lungs.

interstitial emphysema

presence of air in the peribronchial and interstitial tissues of the lungs.

intestinal emphysema

a condition marked by accumulation of gas under the tunica serosa of the intestine.

lobar emphysema

emphysema involving less than all the lobes of the affected lung.

mediastinal emphysema

see pneumomediastinum.

orbital emphysema

may occur after trauma to the head which permits escape of air from the paranasal sinuses; appears as swelling with crepitus under the conjunctiva or periocular skin.

panacinar emphysema, panlobular emphysema

generalized obstructive emphysema affecting all lung segments, with atrophy and dilatation of the alveoli and destruction of the vascular bed.

pulmonary emphysema

distention of the lung caused by overdistention of alveoli and rupture of alveolar walls (alveolar emphysema) and in some cases escape of air into the interstitial spaces (interstitial emphysema). It is a common pathological finding in many diseases of the lung in all species, but also occurs independently, especially in horses, as a principal lesion in chronic obstructive pulmonary disease. It is also a prominent lesion in bovine atypical interstitial pneumonia. It is always secondary to a primary lesion which effectively traps an excessive amount of air in the alveoli. It is characterized clinically by cough, dyspnea, forced expiratory effort and poor work tolerance. A double expiratory effort is a characteristic sign—hence broken wind.

subconjunctival emphysema

occurs with fractures involving the paranasal sinuses.

subcutaneous emphysema

air or gas in the subcutaneous tissues. The characteristic lesion is a soft, mobile swelling which crackles like stiff paper when palpated. There is no pain, nor heat and no ill effects unless the pharyngeal area is sufficiently involved to cause asphyxia.

surgical emphysema

subcutaneous emphysema following operation.

unilateral emphysema

emphysema affecting only one lung, frequently due to congenital defects in circulation.

vesicular emphysema

see panacinar emphysema (above).

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