What is bronchiectasis?|
Bronchiectasis is the irreversible, abnormal dilation of the airways of the lungs associated with various lung conditions, commonly accompanied by chronic infection. Some forms of bronchiectasis are limited to one area of the lung, but some are widespread1.
In this disorder, the airway walls are chronically inflamed, with poor clearing of the increased mucus production. At areas where there is destruction of lung tissue, the lung repairs itself by forming tough, fibrous material, which affect normal lung architecture and function.2
Changes of the lung include reduced lung capacities, poor gas-exchange function, changes of the organisation of blood vessels and overall increased in blood flow through the lungs. These changes can ultimately lead to right heart failure at the later stages of the disorder. This is because there is extra demand on the heart to pump blood through the diseased lung.
What causes bronchiectasis?
Most cases of bronchiectasis develop during childhood, some rare cases are present from birth.
Bronchiectasis can be a result of:
- Infections such as pneumonia or the inhalation of noxious substances, causing inflammation of the bronchial wall. 3
- Abnormal mechanical changes of the lung, for example partial lung collapse (atelectasis) due to obstruction by foreign body, tumour, or excessive mucus production (for example in cystic fibrosis).
Bronchiectasis is commonly associated with:
- Severe pneumonia
- Destructive lung infections, bronchial obstruction (by foreign body, enlarged lymph nodes, excess mucus, tumour)
- Chronic fibrosing lung disease
- Immunologic deficiencies, such as AIDS, impaired immune responses
- Cystic fibrosis
- Syndromes associated with the loss of normal functioning of cilia (hair-like structure lining the airways or clearing lung secretions)
- Young syndrome (associated with infertility in males)
- Inflammation due to a fungus called Aspergillus fumigatus
Chronic inflammation of the walls of the airway is common to all types of bronchiectasis. This is often a result of a vicious circle of bacterial infection, leading to damage to the lung and further predispose the lung to more infections4.
Bronchiectasis mostly occurs in middle aged to elderly population. Patients with congenital lung disease may present at a younger age2. In NZ it is more common in population with a lower socioeconomic status, with poor nutrition, poor housing conditions and often there is a barrier to health care whether it be due to financial reasons or mobility4.
The symptoms of bronchiectasis vary with time and concurrent infections. A common course of symptoms is chronic coughing and sputum production appearing after a severe chest infection with incomplete recovery. Then the condition gradually worsens over some years with increase in sputum production. Haemoptysis (coughing up blood) can sometimes be the first sign that leads to the diagnosis of bronchiectasis. This is a result of the destruction of capillaries (small blood vessels) of the lung or the development of abnormal blood vessels. Other symptoms, especially recurrent fever, chest pain, wheezing, shortness of breath and signs of right heart failure can appear in severe exacerbations.5
By listening to the lungs with a stethoscope, there may be noises (crackles), wheezing, decreased breath sounds (due to airflow obstruction). These signs are often detected especially if the patient is a smoker. With more long-standing bronchiectasis, a change of nail shape may occur which is called clubbing.
Once bronchiectasis is suspected based on signs and symptoms