Emphysema is a type of chronic obstructive airway disease (COPD). People with COPD have limitations in the flow of air through their airways. Emphysema involves the gradual destruction of alveoli in the lungs. The alveoli are air spaces where oxygen is exchanged with carbon dioxide in the blood.
What is going on in the body?
Emphysema results from a loss of elasticity in the walls of small air sacs in the lungs. The walls of the air sacs (alveoli) stretch and break resulting in large air chambers that cannot efficiently perform the exchange of oxygen and carbon dioxide. As a result, the person finds it increasingly difficult to breathe and to exercise without discomfort.
The World Health Organization, or WHO, has recently developed a classification system for the severity of emphysema and other forms of COPD. There are four stages of severity, as outlined below:
- Stage 0, or at risk for COPD. These people have chronic cough and sputum production. Their lung function tests are still normal.
- Stage I, or mild COPD. Individuals in this group have mild limitations in their airflow and changes in their lung function tests. They generally have chronic cough and sputum production.
- Stage II, or moderate COPD. People at this stage have worsening of airflow that leads to shortness of breath with exertion. Their lung function tests show marked limitations.
- Stage III, or severe COPD. Individuals at this stage have severe airflow limitations that impair their quality of life. Their lung function tests are markedly abnormal. They often require home oxygen therapy.
What are the causes and risks of the disease?
Cigarette smoking is the most common cause of emphysema. Long-term exposure to smoke causes destruction of the alveoli. The risk goes up with the amount of tobacco smoked and the number of years of smoking. Emphysema is most common in countries where smoking is prevalent. Passive smoking, or exposure to secondhand smoke, also increases a person's risk for emphysema.
No one knows why only 10% to 15% of smokers get emphysema. Scientists think that certain people are predisposed because of their genes. Another theory is that infections or asthma in childhood makes airways more sensitive to damage. Some think that deeper inhalation of cigarette smoke may deposit more chemicals in the lungs.
Some people produce too little alpha-1-antitrypsin, a protective enzyme secreted in the lungs. These people are much more likely to develop emphysema at an early age, even without exposure to cigarette smoke.
Some of the other risk factors for emphysema include:
- indoor air pollution, such as smoke from home cooking or home heating fuels
- occupational dusts and chemicals
- outdoor air pollution, such as motor vehicle exhaust fumes
What can be done to prevent the disease?
Many risk factors for emphysema can be completely eliminated. Those who smoke must quit, using any of a variety of means. Sources of indoor air pollution can be identified and removed. It's important to avoid secondhand smoke
How is the disease diagnosed?
Diagnosis of emphysema begins with a medical history and physical examination. Lung function tests
can identify emphysema in Stage 0, even before the individual has symptoms. Lung function tests measure how much air a person can take in with a deep breath. They also measure how fast the person can push the air back out of the lungs. The healthcare provider may also order a chest X-ray
and blood tests.
Long Term Effects
What are the long-term effects of the disease?
Chronic obstructive pulmonary diseases, including emphysema, are the fourth leading cause of death in the world. The long-term effects depend on how severe the disease is when diagnosed and if a reduced exposure to the lung irritant occurs. The most effective treatment is quitting smoking. This will typically result in a modest improvement, or at least little or no further decline, in function.
People with emphysema have a higher mortality than those with normal lung function. Causes of death include respiratory failure, lung infections such as pneumonia and influenza, and other diseases related to smoking such as cancer, heart disease, and stroke.
Eventually, severe shortness of breath will limit the person's normal daily activities. People who continue to smoke will have worsening shortness of breath. They may have panic attacks when they are unable to get enough air in and out. People with advanced emphysema are often incapacitated, finding themselves short of breath even when confined to a chair or bed.
What are the risks to others?
Emphysema is not contagious and poses no risk to others.
What are the treatments for the disease?
WHO has identified four components for management of emphysema. These include the following:
- Assess and monitor the disease.
- Reduce the person's risk factors.
- Manage stable emphysema.
- Manage exacerbations, or episodes where symptoms are worse.
Assessment and monitoring
Assessment and monitoring of the disease incorporates the following steps:
- Identify people at risk for emphysema, even if they do not have symptoms.
- Perform lung function tests to measure airflow limitations.
- Do a medical history and physical exam to evaluate symptoms.
Reducing risk factors
Reducing the person's risk factors includes the following measures:
- Avoid vigorous outdoor exercise when air quality is poor.
- Stop smoking, if the person smokes.
- Limit exposure to secondhand smoke.
- Reduce occupational dusts and chemicals.
- Eliminate sources of indoor pollution, such as wood burning stoves.
Managing stable emphysema
Management of stable emphysema includes the following:
- Learn to identify and avoid risk factors.
- Learn to identify problems and seek appropriate treatment.
- Take medications as directed.
Recommendations for management of emphysema are broken down by the severity of the disease. Following are the recommendations for Stage 0 emphysema:
- Get a flu vaccine once or twice a year.
- Get the pneumonia at least once.
- Use antibiotics only for bacterial infections, but not for emphysema itself.
- Identify and eliminate risk factors.
Recommendations for Stage I emphysema are the same as those for Stage 0. In addition, people with Stage I emphysema should use short-acting bronchodilators as needed. Bronchodilators relieve cough and shortness of breath by opening the airways. In general, WHO recommends inhaled bronchodilators rather than oral medications.
Recommendations for Stage II emphysema include the recommendations from Stage I. The following additional measures are recommended for times when symptoms are present.
- Use long-acting bronchodilators on a regular basis.
- Use inhaled glucocorticosteroids in cases of significant cough or shortness of breath.
- Participate in a pulmonary rehabilitation program that uses teaching and exercise to improve lung function.
WHO recommendations for Stage III emphysema are as follows:
- Use long-acting bronchodilators regularly.
- Take short-acting bronchodilators as needed.
- Seek treatment for complications, such as pneumonia.
- Participate in a pulmonary rehabilitation program.
- Use oxygen as needed
Managing worsening symptoms.
People with emphysema may have worsening, or exacerbation, of symptoms when they develop a respiratory infection. Symptoms may also be worsened by cigarette smoke, as well as other factors.
WHO guidelines for management of exacerbations.
- Increase the dose and/or frequency of inhaled bronchodilators.
- Take oral glucocorticosteroids to decrease airway swelling.
- Take antibiotics for bacterial infection.
- Take oxygen by mask or cannula.
- Use a ventilator, or artificial breathing machine.
WHO recommends the use of noninvasive positive pressure ventilation as a way to decrease the need for intubation and mechanical ventilation, and to shorten the hospital stay.
If a person has alpha-1-antitrypsin deficiency, or is a carrier, it is absolutely critical to avoid smoking. Intravenous replacement of the enzyme helps some people, but it is quite expensive.
What are the side effects of the treatments?
Bronchodilators may cause an increased heart rate and blood pressure. Oral glucocorticosteroids can cause increased risk for infection, high blood glucose, and osteoporosis. Antibiotics can cause rash, stomach upset, and allergic reaction.
What happens after treatment for the disease?
Early diagnosis of emphysema and effective treatment can slow its progression. People who eliminate risk factors and follow treatment guidelines have better outcomes. Those who continue to smoke may be increasingly disabled by breathing problems and complications of emphysema.
How is the disease monitored?
Emphysema is monitored through regular visits to the healthcare professional. Lung function tests can be used to monitor limitations in airflow. Any new or worsening symptoms should be reported to the healthcare professional.