Disease, Illness and Condition Library



Bronchietasis is an irreversible widening (dilation) of portions
of the airways (bronchi) resulting from damage to the
bronchial wall.
Bronchietasis can result from several conditions that injure the bronchial wall
directly or indirectly by interfering with its normal defenses against potentially
harmful substances. The most common cause is severe respiratory infections.
Immune deficiency disorders, hereditary disorders (such as cystic fibrosis, in
which abnormal mucus impairs the ability of the cilia to clear the bronchi of
organisms that cause infections), and mechanical factors (such as bronchial
obstruction caused by an inhaled object, a lung tumor, or other disorders) may
predispose a person to infections that lead to bronchietasis. A small number
of cases probably result from inhaling toxic substances that injure the bronchi,
such as noxious fumes, gases, smoke (including tobacco smoke), and injurious
dust (silica, coal dust).
In broncheictasis, areas of the bronchial wall are destroyed and become
chronically inflamed, ciliated cells are damaged or destroyed, and secretions
(mucus) accumulate. Also, the bronchial wall becomes less elastic – the
affected airways become wider and flabby and may develop outpouchings or
sacs that resemble tiny balloons. The increased mucus production promotes
the growth of bacteria, often obstructs the bronchi, and leads to pooling of
infected secretions and further damage to the bronchial wall. The inflammation
and infection can extend to the small air sacs of the lungs (alveoli) and produce
pneumonia, scarring, and a loss of functioning lung tissue.
In severe cases, scarring and a loss of blood vessels in the lung can ultimately
strain the right side of the heart as the heart tries to pump blood through the
altered vessels. Also, inflammation and an increased number of blood vessels
in the bronchial wall (which are fragile) can result in a person coughing up
blood. Blockage of the damaged airways can lead to abnormally low levels
of oxygen in the blood.
Bronchietasis may affect many areas of the lung, or it may appear in only
one or two areas. Typically, bronchiectasis causes widening of medium sized
bronchi, but often smaller bronchi become scarred and destroyed.
Occasionally, a form of bronchiectasis affecting larger bronchi occurs in allergic
bronchopulmonary aspergillosis, a condition caused by an allergic response to
the Aspergillus fungus.
Symptoms
Bronchiectasis can develop at any age; often, the process begins in early
childhood. However, symptoms may not emerge until much later. In most
people, symptoms begin slowly, usually after a respiratory infection, and tend
to worsen over the years. Most people develop a chronic cough that produces
sputum; the amount and type of sputum depend on how extensive the disease
is and whether there is and whether there is a complicating infection. Often, the
person has coughing spells only early in the morning and late in the day.
Coughing up blood is common and may be the first or only symptom.
Recurrent fever or chest pain, with or without frequent bouts of pneumonia,
may also occur. People with widespread bronchiectasis may develop wheezing
or shortness of breath; they may also have chronic bronchitis, emphysema, or
asthma. Very severe cases of bronchiectasis, which occur more commonly in
underdeveloped countries and in people who have advanced cystic fibrosis,
may impair breathing and the lung’s ability to oxygenate the blood and free the
body of carbon dioxide, a condition called respiratory failure. Very severe
bronchiectasis may also strain the right side of the heart and lead to
cor pulmonale.
Diagnosis
Doctors may suspect bronchiectasis because of a person’s symptoms or the
presence of a condition thought to cause bronchietasis. Tests are performed
to confirm the diagnosis and evaluate the extent and location of the disease.
Chest x-rays can often detect the lung changes caused by bronchiectasis;
however, occasionally, results are normal. Computed tomography (CT) is
usually the most sensitive test to identify and confirm the diagnosis and to
determine the extent and severity of the disease; these are important factors
when surgical treatment is being considered.
After bronchiectasis is diagnosed, tests are often done to check for diseases
that may be contributing to it, if they were not previously identified. Such tests
may include measuring the immunoglobulin levels in blood, testing for HIV
infection and other immune system disorders, measuring the salt levels in
sweat (which are abnormal in those suffering from cystic fibrosis), and
examining nasal bronchial, or sperm specimens with a special microscope
and other tests to determine if the cilia are structurally or functionally defective.
When bronchiectasis is limited to one area – for example, a lung lobe or
segment – doctors may perform bronchoscopy to determine whether an
inhaled foreign object or lung tumor is the cause. Other tests may be
performed to identify underlying diseases, such as allergic
bronchopulmonary aspergillosis or tuberculosis.
Genetic testing for cystic fibrosis may be needed when there is a family
history, repeated respiratory infections, or other suspicious findings in a
child or young adult, even when other typical features of cystic fibrosis
are not present.
Prevention
Early detection and treatment of conditions that tend to cause bronchiectasis
may prevent the development of bronchiectasis or reduce its severity. More
than 50% of broncheictasis in children can be correctly diagnosed and
promptly treated.
Childhood immunizations against measles and whooping cough, suitable use
of antibiotics, and improved living conditions and nutrition have dramatically
reduced the number of people who develop bronchietasis. Annual influenza
vaccines, use of the pneumococcal vaccine, and use of appropriate drugs
early in the course of infections (such as pneumonia and tuberculosis) help
to prevent bronchiectasis or reduce its severity. Receiving immunoglobulin
for an immunoglobulin deficiency syndrome may prevent recurring infections.
In people who have allergic bronchopulmonary aspergillosis, the appropriate
use of corticosteroids and perhaps the antifungal drug itraconazole may
reduce bronchial damage that results in bronchiectasis.
Avoiding toxic fumes, gases, smoke, and injurious dusts also helps prevent
bronchietasis or reduce its severity. Inhalation of foreign objects into the
airways by children may be prevented by carefully watching what they put
in their mouth. Additionally, avoiding over sedation from drugs or alcohol
and seeking medical attention for neurologic symptoms (such as impaired
consciousness) or gastrointestinal symptoms (such as difficulty swallowing
and regurgitation or coughing after eating) may help to prevent aspiration.
Also, drops of mineral oil or other oils should never be placed in the mouth
or nose because they can be inhaled into the lungs.
Treatment and Prognosis
Treatment of bronchiectasis is aimed at against eradicating infections,
decreasing the buildup of mucus and inflammation, relieving airway
obstruction, and reducing complications (such as coughing up of blood,
low oxygen levels in the blood, respiratory failure, and cor pulmonale).
Drugs that suppress coughing may worsen the condition and generally
should not be used.
Infections are treated with antibiotics, bronchodilators, and physical therapy
to promote drainage or secretions. Sometimes antibiotics are prescribed for
a long period to prevent recurring infections, especially in people who have
cystic fibrosis.
For inflammation and the buildup of mucus, anti-inflammatory drugs such as
inhaled corticosteroids and drugs that thin the pus and mucus (mucolytics)
may also be given, although the effectiveness of mucolytics is uncertain.
To help drain the mucus, postural drainage and chest percussion are used.
To detect and treat a bronchial obstruction, bronchoscopy can be used before
severe damage occurs. Rarely, part of a lung needs to be surgically removed.
Such surgery usually is an option only if the disease is confined to one lung,
or preferably to one lung lobe or segment. Surgery may be considered for
people who have recurrent infections despite treatment or who cough up large
amounts of blood. Alternatively, a doctor may intentionally block a bleeding
bronchial vessel by using a procedure called bronchial arterial embolization.
If a person’s blood oxygen level is low, oxygen therapy may help prevent
complications such as cor pulmonale. If the person has wheezing or shortness
of breath, corticosteroids taken with or without bronchodilators often help.
Respiratory failure, if present, should be treated.
Lung transplantation can be performed in certain people who have advanced
bronchiectasis, mostly those who also have advanced cystic fibrosis. Five year
survival rates as high as 65 to 75% have been reported when a heart-lung or
double lung transplantation is used. Pulmonary function (as measured by the
amount of air in the lungs and the rate and amount moving in and out of the
lungs with each breath) usually improves within 6 months, and the improvement
may be sustained for at least 5 years.
Overall prognosis for people with bronchiectasis depends on how well
infection and other complications are prevented or controlled. Because
other conditions (such as chronic bronchitis, emphysema, pulmonary
hypertension, cor pulmonale, or other serious diseases that affect the
whole body (systmeic diseases) diminish the effectiveness of prevention
and treatment, people with these conditions tend to have a less optimistic
prognosis.