- What Is It?
- 4 Stages
- Risk Factors
- Life Expectancy
Emphysema definition and facts
- Emphysema is a destructive disease of the lung in which the alveoli (small sacs) that promote oxygen exchange between the air and the bloodstream are destroyed.
- Smoking is the primary cause of emphysema, which makes it a preventable illness.
- There are also less common genetic causes of emphysema including alpha-1 antitrypsin deficiency.
- The primary symptom of emphysema is shortness of breath. It is a progressive complaint by affected individuals, worsening over time. Early in the disease, shortness of breath may occur with exercise and activity but symptoms gradually worsen and may occur at rest.
- The diagnosis of emphysema is based upon history, physical examination, and pulmonary function studies.
- Once present, emphysema is not curable, but its symptoms are controllable.
- Medication regimens are available to preserve function for daily activities and quality of life for an individual with emphysema.
- Oxygen supplementation may be required for a person with emphysema.
- Exercise training and education are essential components of emphysema therapy and pulmonary rehabilitation.
- Surgical options for individuals with emphysema have been developed and but are not expected to be available for widespread use.
- Emphysema does not affect the quantity of life, but rather quality of life. There are no studies that can predict life expectancy in individuals with emphysema.
What is emphysema?
Emphysema is a chronic obstructive pulmonary disease (COPD) that presents as an abnormal and permanent enlargement of air spaces distal to the terminal bronchioles. It frequently occurs in association with obstructive pulmonary problems and chronic bronchitis. It is unusual for someone to have pure emphysema unless it is a result of genetic abnormalities. Most people have some combination of emphysema and chronic bronchitis with varying degrees of airway bronchospasm. This condition is commonly referred to as COPD (and in the United Kingdom, as chronic obstructive lung disease, COLD).
There are three morphological types of emphysema; 1) centriacinar, 2) panacinar, and 3) paraseptal.
- Centriacinar begins in the respiratory bronchioles and spreads peripherally mainly in the upper half of the lungs and is usually associated with long-standing cigarette smoking.
- Panacinar predominates in the lower half of the lungs and destroys the alveolar tissue and is associated with homozygous alpha-1 antitrypsin deficiency, a genetic disease.
- Paraseptal emphysema preferentially localizes around the septae of the lungs or pleura, often associated with inflammatory processes, like prior lung infections.
What are the four stages of emphysema?
Emphysema staging helps determine how much lung damage is present and how severe it is. The Global Initiative for Chronic Obstructive Lung Disease (GOLD) uses FEV1 measurements to help with this determination:
|I = mild||greater than or equal to 80% predicted|
|II = moderate||less than 80%, greater than 50% predicted|
|III = severe||Less than 50%, greater than 30% predicted|
|IV = very severe||Less than 30% predicted, or less than 50% in chronic respiratory failure|
What causes emphysema?
As stated previously in the risk factors section, there can be many causes for the development of emphysema. However, the majority of cases of emphysema (COPD) in the United States and other countries are caused by exposure to cigarette smoke. Although genetics may play a role, the inflammation mediated by the body's cells (neutrophils, macrophages and lymphocytes) is usually triggered by exposure to inflammatory compounds, many of which are found in tobacco smoke. The response of the body's immune system leads to destruction of elastin and other structural elements in the lungs, ultimately producing areas in the lungs that cannot function normally.
People with alpha-1 antitrypsin deficiency have an inherited autosomal condition that results in increased breakdown of elastin in the lungs, resulting in COPD (emphysema). When foreign irritants and substances enter the alveoli, usually by inhalation, an inflammatory process is initiated. Chemical messages are sent out recruiting white cells to remove this foreign material. These cells release enzymes that destroy this substance. Normally, these enzymes, often trypsins (protein desolving enzymes) work to remove this material. The body has anti-trypsin enzymes that destroy the trypsin when the foreign substance is no more. In the case of the genetic alpha one antitrypsin deficiency, these enzymes continue to work unabated destroying normal adjacent lung tissue, resulting in emphysema. This is often referred to as the "innocent bystander" effect.
What are the risk factors for emphysema?
The major factors that increase the risk for developing emphysema are:
Smoking: Smoking is one of the major risk factors for developing emphysema; the risk increases as the number of years the person has been smoking increases, and is related to the amount of tobacco smoked (for example, three cigarettes a day versus a pack and a half per day); smoking is a major risk factor also for developing lung cancer.
Exposure to secondhand smoke: the risk factors or emphysema increase for people exposed to secondhand smoke according to the number of years exposed to secondhand smoke, and the amount of smoke the person is exposed to.
Exposure to fumes or dust in the environment: People that work in close association with chemical fumes or dusts generated in mining, chemical plants or other industries are higher risks for developing emphysema; these risks are further increased if the person smokes tobacco.
Pollution: Air pollution caused by fumes from vehicles, electrical generating plants that use coal and other fumes produce increases the risk of emphysema.
In the underdeveloped parts of the world, indoor air pollution primarily from open wood flames used for cooking is the primary mechanism for acquiring emphysema.
What are the signs and symptoms of emphysema?
Emphysema is a progressive disease with the most common and characteristic symptoms of cough and shortness of breath caused by prolonged smoke exposure.
Affected individuals with alpha-1 antitrypsin deficiency tend to develop symptoms of emphysema at earlier ages. Emphysema is a subtype of chronic obstructive pulmonary disease (COPD in the US; COLD, chronic obstructive lung disease in the United Kingdom). Most patients, except in those in whose disease is the result of a genetic deficiency (alpha-1 antitrypsin deficiency), have variable manifestations of the different components of COPD which include:
Each of the subtypes has characteristic symptoms; those primarily associated with emphysema are shortness of breath and wheezing. Initially the shortness of breath (dyspnea) occurs with activity; as time continues and the disease progresses, the episodes of dyspnea occur more frequently eventually occurring at rest making routine daily activities difficult to perform and thus alters the lifestyle.
How is emphysema diagnosed?
As is the case with most illnesses, the health-care professional will take a careful history to learn about the lung and breathing symptoms.
- How long has the shortness of breath been present?
- What makes it better?
- What makes it worse?
- Has there been an infection recently?
- Have the symptoms been getting more severe?
- Does the patient smoke?
- Does the patient have exposure to secondhand smoke or other toxic fumes?
- Are there other exposures of diseases that may be contributing to the shortness of breath?
- Is there a family history of lung disease?
Physical examination will concentrate on the lung findings, but may also include the heart and the circulatory system.
- Is there an increased respiratory rate?
- Is the patient short of breath just sitting in the examination room?
- In addition to the ribs and the diaphragm, is the patient using the intercostal muscles (those between the ribs) and neck muscles to breathe? When used, accessory muscles cause the appearance of indrawing, where there is observable sucking in of muscles during the breathing cycle. This is normally seen in people who have just exerted themselves as the body recovers from exercise or work. In patients with emphysema it may be observed at rest.
- Does the chest appear enlarged or barrel-shaped?
- Does the chest cavity sound hollower than it should?
- Does exhalation take longer than it should? Since the elasticity of the lung has been lost, it takes longer for air to be forced out in the breathing cycle.
- Is the movement of the diaphragm decreased?
- Is the patient cyanotic (having a blue tinge to the skin color signifying lack of oxygen in the blood)?
- When listening to the lungs, are there wheezes present, especially if the patient is asked to exhale quickly?
- Is clubbing present? This is a characteristic change in the fingernails and tips of the fingers associated with lung disease and chronic hypoxia.
Exams and tests
Oximetry is a non-invasive test, in which a sensor is taped or clipped onto a finger or earlobe to measure the percentage of red blood cells that have oxygen. This value is usually greater than 92%. Results less than 90% may signal the need for supplemental oxygen for home use.
A complete blood cell count (CBC) may be performed to check for an increase in the number of red blood cells. In response to lower blood oxygen concentrations, the body manufactures more red blood cells to try to deliver as much oxygen as possible to cells.
Alpha-1 antitrypsin levels may be measured to look for the genetic form of emphysema.
An arterial blood gas test will measure the amount of oxygen and carbon dioxide in the blood and combined with other measurements can help the healthcare provider decide whether the body has been able to adapt to the lower oxygen concentrations in the body. In some laboratories, the arterial blood gas result will include a carbon monoxide percentage, most often found in the body because of smoking. For each hemoglobin molecule that has carbon monoxide attached, there is one less available that can carry oxygen.
The arterial blood gas can also give parameters to establish the diagnosis of chronic respiratory failure. The diagnosis of chronic respiratory can be made when the measured oxygen level drops below 60 mmHg (millimeters of mercury) and the carbon dioxide level rises above 50 mm Hg, the diagnosis of chronic respiratory failure can be made.
A plain chest X-ray may show lungs that have become too inflated and have lost normal lung markings, consistent with destruction of alveoli and lung tissue.
A CT scan can reveal more detail regarding the amount of lung destruction but is not a normal part of the evaluation of patients with emphysema.
Pulmonary function tests
Pulmonary function tests or spirometry can measure the air flow into and out of the lungs and be used to predict the severity of emphysema. By blowing into a machine, the amount of air that is moved and how quickly it moves can be calculated and provides information about lung damage. Results are compared to a "normal" person of the same age, sex, and size.
Some measurements include:
- FVC (forced vital capacity): the amount of air that can be forcibly exhaled after the largest breath possible.
- FEV1 (forced expiratory volume in 1 second): the amount of air that is forcibly exhaled in 1 second. Even though total air exhalation may be less affected, as the lung loses its elasticity, it takes longer for the air to get out and FEV1 becomes a good marker for disease severity.
- FEV (forced expiratory volume): can be measured throughout the exhalation cycle often at 25%, 50%, and 75% to help measure function of different sized bronchi and bronchioles.
- PEF (peak expiratory flow): maximal speed of air during exhalation.
- DLCO (diffusion capacity): measures how much carbon monoxide can be inhaled and absorbed into the bloodstream within a period of time. A small amount of tracer carbon monoxide is inhaled and then quickly exhaled. The amount of carbon monoxide in the exhaled air is measured and determines how well the lungs work in absorbing the gas. This helps determine and measure lung function.
What is the treatment for emphysema?
The first treatment for patients with emphysema is smoking cessation if they are currently smoking tobacco. This is a difficult lifestyle change for many patients, and without support from their doctors, family members, and friends; this most important treatment will likely fail. The best way to accomplish this difficult task is outlined in the "quitting smoking" section. In addition, there is pharmacological and surgical therapy available for emphysema patients and these therapies will be discussed in the next sections.
Quitting smoking is the most effective therapy for people with emphysema. Consequently, successful cessation is a major goal for people with COPD/emphysema. This goal usually can be reached with cooperation between the doctor, patient, family members, and friends. Quitting smoking usually requires patient education about the risks of smoking, methods to help the patient quit smoking (including a target date to quit), and follow-up support. Many people will relapse, but they still should be encouraged to try to change their lifestyle and attempt to quit again.
Many people may benefit from both self-help and group smoking cessation programs. Patients need to understand that nicotine is responsible for their addiction to smoking and may benefit from a program that allows them to slowly withdraw from nicotine addiction. There are several types of pharmacological interventions such as nicotine chewing gum, transdermal nicotine patches, and other treatments such as varenicline (Chantix) and Zyban that may be used to help the patient overcome their nicotine addiction.
Bronchodilators are used to relax the smooth muscles that surround the bronchioles, allowing the breathing tubes to dilate and air to flow more freely. These medications can be inhaled using an MDI (metered dose inhaler), powder inhaler devices, or a nebulizer machine These medications can either be short or long acting.
The short acting bronchodilators include the albuterol agents (Ventolin HFA, Proventil HFA, and Pro Air HFA) and the anticholinergic agent, ipratropium bromide (Atrovent).
As an aside, in the past patients have been instructed to count the number of puffs used from these devices or "float" the inhaler in water to determine the amount of remaining medicine available. The HFA devices cannot be floated, and counting of the number of puffs is the only available method of determining the continued presence of medication. One device, Ventolin HFA, has a built in counter. It is important to understand that the mere presence of propellant coming from the inhaler does not necessarily mean that medication is present.
The long acting agents include salmeterol (Serevent), formoterol (Foradil) and tiotropium (Spiriva). Often the long acting bronchodilator is used for controlling the symptoms of emphysema as maintenance therapy, and the short acting one is used when symptoms flare up (rescue therapy).
It is important that the patient know which medication is prescribed, since long acting inhalers cannot be used for rescue, because of their delayed onset of action. Sometimes, patients will seek medical care in an extremely ill state because they have been using the long-acting controller drug as their rescue inhaler. There are 120 or 200 puffs in a short acting MDI, and one puffer should last a significant amount of time. If not, the emphysema is not under control and the patient and health care professional will work on long acting solutions. Many patients with emphysema also have home nebulizers that can deliver albuterol and ipratroprium as part of their control regimen.
Since most patients do not have pure emphysema and usually also have other components of COPD, combined therapy is often prescribed which includes a long-acting bronchodilator and an inhaled corticosteroid. The inhaled corticosteroid (ICS) helps suppress the inflammatory components of COPD. While the bronchodilators work to relax the smooth muscle surrounding the breathing tubes, steroids decrease the inflammation within the walls of the tubes themselves.
These agents like Advair, which is a mixture of salmeterol (Serevent) and fluticasone (Flovent), an ICS, simplify treatment by combining both therapies into a single inhaler device. Another combination inhaler is formoterol and budesonide (Symbicort).
Many patients with emphysema need only take steroid inhalers when their symptoms flare, but others require daily therapy. Corticosteroids have direct action on the lung tissue and absorption of inhaled corticosteroids into the blood stream is minimal. Prednisone, an oral corticosteroid, can be taken in addition to the inhaled steroid should further anti-inflammatory effects be required. Moreover, these may be prescribed to be taken only during an acute flare of the emphysema, or may be required to be taken on a daily basis by those patients with more severe disease.
In emergency situations, corticosteroids may be injected intravenously.
Since patients with emphysema are at risk for infections like pneumonia, antibiotics may be prescribed when the usually clear sputum changes color, or when the patient presents with systemic signs of an infection (fever, chills, weakness).
As the disease progresses, patients may require supplemental oxygen to be able to function. Often it begins with nighttime use, then with exercise, and as the disease worsens, the need to use oxygen during the day for routine activities increases.
Surgery for emphysema
Lung volume reduction surgery is another surgical technique. It may be an option for patients with severe emphysema symptoms that do not respond to attempts at medical therapy. In this technique, about 20% to 30% of tissue from both lungs is removed; the area removed is usually the lung tissue sections that have minimal or no function.
Finally, lung transplantation is a possibility for certain selected patients. Patients with COPD/emphysema are the largest category of patients that undergo lung transplantation.
Pulmonary rehabilitation for emphysema
Pulmonary rehabilitation involves methods to improve the patient's quality of life by keeping airways open and preventing or reducing secondary complications such as infections and recurrent respiratory symptoms. Pulmonary rehabilitation involves input from doctors and nurses, dietitians, respiratory therapists, exercise physiologists, and many others. The goal of pulmonary rehabilitation is to educate the patient and family about the disease process, encourage routine exercise increasing in graded increments, smoking cessation, medications and medical management, respiratory and chest physiotherapy, and exercises to improve breathing. In addition, the program should offer psychological and social support for the patient. Pulmonary rehabilitation can teach patients how better to control their disease and live a more vibrant and enjoyable life.
What is the life expectancy and outlook for someone with emphysema?
Emphysema is a disease that affects the quality of life and not necessarily the quantity of life. The goal for the treatment of emphysema is to prevent further lung damage and to maximize the function of the remaining healthy lung tissue.
Symptoms of emphysema occur because the body is not being supplied with adequate oxygen and because it takes significant effort to take deeper breaths. These both contribute to the very miserable sensation of constantly feeling short of breath.
There are no studies that have been able to predict mortality from emphysema, but studies from the American Lung Association and the US Centers for Disease Control and Prevention report that 133,000 people died from COPD in 2009. The most recent National Health Interview Survey performed in 2011 found that 4.7 million people had been diagnosed with emphysema and that 24.1 million people had evidence of impaired lung function.
The BODE score can help measure the quality of life and prognosis for future functions.
- B = Body Mass Index (BMI).
- O = Obstruction. Lung function based on pulmonary function tests.
- D = Dyspnea (breathlessness)
- E = Exercise capacity. How far the emphysema patient can walk in 6 minutes
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