6. Bronchiectasis

Bronchiectasis is an uncommon chronic obstructive airway disease in which bronchi become damaged and collapse easily. The walls of the bronchi contain elastic and muscle fibers, which allow the bronchial tubes to expand and contract while maintaining their structure. In people with bronchiectasis, the elastic and muscular components in the walls of medium-sized bronchi are permanently destroyed. This damage causes the bronchi to collapse, especially with exhalation, which interferes with the ability to breathe. There are several possible causes, but bronchiectasis most often occurs following a respiratory infection.

The condition may affect only one or two areas of the lung, or it may be more widespread. The areas that are affected will be inflamed and possibly scarred. The smaller bronchioles beyond the affected medium-sized bronchi may be destroyed. The abnormally dilated bronchi will have severely impaired ability to clear mucus, and the excess mucus that builds up in the lungs can harbor bacteria or other infectious agents. This may lead to a vicious cycle of a respiratory infection that damages the bronchi, which causes dilation of the bronchi and impaired ability to clear mucus. The excess mucus traps bacteria, thus continuing the infection and causing additional damage to the bronchi.

Very rarely, infants and children can develop bronchiectasis from a birth defect that impedes the normal development of the lungs. The disease more often affects adults or children who have suffered a chronic or recurring lung infection, or who have an inherited lung disease called cystic fibrosis.

The exact number of people afflicted with bronchiectasis is not known, largely because it tends to be excluded from studies that assess the incidence of obstructive airway diseases. Older data suggest that about 100,000 Americans may have the disease. It is more common in women, and the prevalence increases with age. For unknown reasons, Native Americans living in Alaska are four times more likely than the general population to have bronchiectasis.

What Causes Bronchiectasis?

Bronchiectasis may occur in people who’ve had poorly treated or untreated lung infections, such as tuberculosis, pertussis, or severe bacterial pneumonia. Measles, whooping cough, influenza, fungal infections, mycobacterial infections, and adenoviral infection are other possible causes. Bronchiectasis due to scarring as a result of severe infection is uncommon in the U.S. and other developed countries, partly because of the widespread use of antibiotics and other effective treatments for these infections. However bronchiectasis due to slowly progressive lung infections does still occur in the developed world.

Bacteria

The most common bacterial family to cause bronchiectasis in this manner is the mycobacteria family. Worldwide, Mycobacterium tuberculosis, the bacteria that causes TB, is a common cause of bronchiectasis. In the U.S. other, non-communicable, mycobacteria are more common causes of bronchiectasis. Of these, the bacteria Mycobacterium avium is the most commonly found. Interestingly, these bacteria tend to affect smokers with emphysema and older, thin, non-smoking Caucasian women more than other groups. Scientists have no idea why these patients seem more susceptible to these bacteria.

Obstructions

Obstruction of bronchial tubes can also be a cause of bronchiectasis. For example, an inhaled object (such as unchewed food) can lodge in the airways and cause an obstruction. This obstruction may lead to an infection, with subsequent development of bronchiectasis. Enlarged lymph nodes, a tumor in the lung, or a mucus plug (see below) can also cause an obstruction in the airways that leads to bronchiectasis.

Cystic Fibrosis

Cystic fibrosis is an inherited disease in which an abnormal gene causes mucus to be too thick and sticky. Mucus can build up in the lungs, causing an obstruction. These obstructions are called mucus plugs. Most people with cystic fibrosis develop severe bronchiectasis as a result of the airway obstruction from mucus plugs and chronic lung infection.

Other Causes

Other possible causes of bronchiectasis include a genetic condition called Young syndrome that is similar to cystic fibrosis, and a rare inherited disorder called primary ciliary dyskinesia, which causes poor mucus clearance and recurring lung infections. People with a compromised immune system may also be susceptible to bronchiectasis. People with alpha-1 antitrypsin deficiency (see page 15) may develop bronchiectasis, as can those with autoimmune diseases such as rheumatoid arthritis or Sjögren’s syndrome, or inflammatory bowel disease, particularly ulcerative colitis. Exposure to toxic gas, such as chlorine gas and ammonia, also may cause bronchiectasis.

Symptoms of Bronchiectasis

Symptoms of bronchiectasis usually begin slowly, following a respiratory tract infection. A longstanding (months to years) daily cough with sputum production is the chief symptom. Some people will cough up small amounts of blood as a result of damage to the airways from infection. People with bronchiectasis may also have shortness of breath, wheezing, chest pain, fever, weakness, and weight loss. The condition may also produce relatively few symptoms.

Many people with the condition will have repeated bouts of lung infections (bronchitis, pneumonia) that require antibiotics.

Diagnosing Bronchiectasis

Because the symptoms of bronchiectasis can be similar to those of other lung diseases, including asthma, COPD, and pneumonia, the physician will look for the conditions associated with bronchiectasis, such as recurring or untreated lung infections, cystic fibrosis, or others. If bronchiectasis is suspected, the sputum that is produced from coughing will be examined for the presence of white blood cells (which is a sign of infection), and may be sent for culture to see if there is predominant bacteria in the sputum.

A CT scan (see page 21) may be used to confirm the diagnosis and to determine the extent of the disease. Pulmonary function tests, such as spirometry (see page 19), are not necessary to make the diagnosis, but may be performed to assess lung function. Additional tests may be performed to identify the underlying cause. This is important because some causes of bronchiectasis are treatable.

Treatment for Bronchiectasis

The treatment for bronchiectasis will partly depend on the underlying cause of the condition. General recommendations for all patients with bronchiectasis include limiting exposure to inhaled toxins, such as air pollution and secondhand smoke. Those who smoke should quit (see page 36). Immunizations for influenza and pneumonia are recommended (see page 65 and page 72). Getting adequate nutrition is essential, and may require taking nutritional supplements.

Overall, treatment for bronchiectasis is effective and people with the disease have the same life expectancy as people with asthma or COPD. Those with cystic fibrosis are the exception, due to the severity of the bronchiectasis that occurs in patients with cystic fibrosis, and due to its unique cause.

Treatments Include:

Antibiotics

Antibiotics are the main treatment for most people with bronchiectasis. Antibiotics that may be used include amoxicillin (Amoxil), tetracycline (Sumycin), trimethoprim-sulfamethoxazole (Bactrim, Septra), and azithromycin (Zithromax), among others. Antibiotics are usually given for seven to 14 days, but may be given for longer periods to prevent infections from coming back.

Mechanical Methods

Mechanical methods may be used to help clear the lungs of the large amounts of mucus that can build up. For example, a person who has bronchiectasis may undergo postural drainage with percussion or vibration. Postural drainage entails being placed in position with the head and/or chest down to allow the force of gravity to help clear the mucus. This may be combined with percussion, in which a health care professional will tap the chest with a cupped hand for about one to two minutes. This can help to break up thick mucus.

A procedure called vibration may also accompany postural drainage. This involves a healthcare professional placing his or her hand on the patient’s chest and creating vibrations. This is often done using a vibrating vest.

Other devices that may be used to help clear mucus include flutter devices, intrapulmonic percussive ventilation devices, acapella devices, and incentive spirometry.

Bronchodilators and Corticosteroids

Bronchodilators and corticosteroids (see pages 24 and 25) may be used for some patients with bronchiectasis, but there is no conclusive evidence that these are beneficial for all people with the condition.

Surgery

Surgery to remove damaged parts of the lung may be an option for some bronchiectasis patients. Surgery is generally reserved for patients in whom the lung damage is confined to or markedly more severe in a specific area (rather than widespread throughout the lung), and who are not helped with antibiotics. Some people with severe bronchiectasis, such as advanced cystic fibrosis, may be candidates for lung transplantation.

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