Bronchiectasis
Overview
Bronchiectasis or primary ciliary dyskinesia is very rare disorder where the cilia fail to move. The cilia are tiny, hair-like structures found in the respiratory and ear passages and help to clear debris and mucus. The lack of ciliary movement can cause a lung disease called bronchiectasis where a build up of mucus causes infections and airway damage. The airways then become enlarged. The condition can become progressively worse with time and can result in serious breathing problems.
Symptoms
Common symptoms for bronchiectasis or primary ciliary dyskinesia
- Frequent lung infections
- Dilated airways
- Chronic cough
- Shortness of breath
- Wheezing
- Fatigue
- Finger clubbing
- Pallor
- Breath odor
- Weakness
- Productive cough
Causes
Bronchiectasis has both congenital and acquired causes, with the latter more frequent.
Acquired causes
Tuberculosis, pneumonia, inhaled foreign bodies, allergic bronchopulmonary aspergillosis and bronchial tumours are the major acquired causes of bronchiectasis. Infective causes associated with bronchiectasis include infections caused by the Staphylococcus, Klebsiella, or Bordetella pertussis, the causative agent of whooping cough.
Aspiration of ammonia and other toxic gases, pulmonary aspiration, alcoholism, heroin (drug use), various allergies all appear to be linked to the development of bronchiectasis.
Various immunological and lifestyle factors have also been linked to the development of bronchiectasis:
- Childhood Acquired Immune Deficiency Syndrome (AIDS), which predisposes patients to a variety of pulmonary ailments, such as pneumonia and other opportunistic infections.
- Inflammatory bowel disease, especially ulcerative colitis. It can occur in Crohn's disease as well, but does so less frequently. Bronchiectasis in this situation usually stems from various allergic responses to inhaled fungal spores. A Hiatal hernia can cause Bronchiectasis when the stomach acid that is aspirated into the lungs causes tissue damage.
- Rheumatoid arthritis sufferers who smoke appear to have a tenfold increased prevalence of the disease. Still, it is unclear as to whether or not cigarette smoke is a specific primary cause of bronchiectasis.
No cause is identified in up to 50% of non-cystic-fibrosis related bronchiectasis.
Congenital causes
Bronchiectasis may result from congenital infections that affect cilia motility or ion transport. Kartagener syndrome is one such disorder of cilia motility linked to the development of bronchiectasis. A common cause is cystic fibrosis, which affects chloride ion transport, in which a small number of patients develop severe localized bronchiectasis. Young's syndrome, which is clinically similar to cystic fibrosis, is thought to significantly contribute to the development of bronchiectasis. This is due to the occurrence of chronic infections of the sinuses and bronchiole tree.
Other less-common congenital causes include primary immunodeficiencies, due to the weakened or nonexistent immune system response to severe, recurrent infections that commonly affect the lung. Several other congenital disorders can also lead to bronchiectasis, including Williams-Campbell syndrome and Marfan syndrome.
Patients with alpha 1-antitrypsin deficiency have been found to be particularly susceptible to bronchiectasis, for unknown reasons.
Prevention
In order to prevent bronchiectasis, children should be immunized against measles, pertussis, pneumonia, and other acute respiratory infections of childhood. While smoking has not been found to be a direct cause of bronchiectasis, it is certainly an irritant that all patients should avoid in order to prevent the development of infections (such as bronchitis) and further complications.
Treatments to slow down the progression of this chronic disease include keeping bronchial airways clear and secretions weakened through various forms of pneumotherapy. Aggressively treating bronchial infections with antibiotics to prevent the destructive cycle of infection, damage to bronchial tubes, and more infection is also standard treatment. Regular vaccination against pneumonia, influenza and pertussis are generally advised. A healthy body mass index and regular doctor visits may have beneficial effects on the prevention of progressing bronchiectasis. The presence of hypoxemia, hypercapnia, dyspnea level and radiographic extent can greatly affect the mortality rate from this disease.
Diagnosis
Bronchiectasis may be diagnosed clinically or on review of imaging. The British Thoracic Society recommends all non cystic-fibrosis-related bronchiectasis be confirmed by CT. CT may reveal tree-in-bud abnormalities, dilated bronchi, and cysts with defined borders.
Other investigations typically performed at diagnosis include blood tests, sputum cultures, and sometimes tests for specific genetic disorders.
Prognosis
Congenital causes of bronchiectasis (exp:cystic fibrosis) usually have a worse prognosis than bronchiectasis developed from acquired diseases. Those (from acquired diseases) can have a good prognosis if bronchiectasis is early recognized and the treatment is done.
Treatment
Treatment of bronchiectasis includes controlling infections and bronchial secretions, relieving airway obstructions, removal of affected portions of lung by surgical removal or artery embolization and preventing complications. This includes the prolonged usage of antibiotics to prevent detrimental infections, as well as eliminating accumulated fluid with postural drainage and chest physiotherapy. Postural drainage techniques, aided by physiotherapists and respiratory therapists, are an important mainstay of treatment. Airway clearance techniques appear useful.
Surgery may also be used to treat localized bronchiectasis, removing obstructions that could cause progression of the disease.
Inhaled steroid therapy that is consistently adhered to can reduce sputum production and decrease airway constriction over a period of time, and help prevent progression of bronchiectasis. This is not recommended for routine use in children. One commonly used therapy is beclometasone dipropionate. Although not approved for use in any country, mannitol dry inhalation powder, has been granted orphan drug status by the FDA for use in people with bronchiectasis and with cystic fibrosis.