- What is Bronchiectasis
- Statistics on Bronchiectasis
- Risk Factors for Bronchiectasis
- Progression of Bronchiectasis
- Symptoms of Bronchiectasis
- Clinical Examination of Bronchiectasis
- How is Bronchiectasis Diagnosed?
- Prognosis of Bronchiectasis
- How is Bronchiectasis Treated?
- Bronchiectasis References
What is BronchiectasisBronchiectasis is a disease of the lung.
The lung is composed of large airways (bronchi), which progressively divide and become smaller airways (bronchioles), which eventually terminate as ‘alveoli’ – the small folded membranes, shaped like a bunch of grapes where gas exchange takes place. (Learn more about the The Respiratory System.)
The small and medium airways are normally free of mucus. Any mucus present is sweeped up by the cilia to the upper airways, and the person then coughs it up.
Bronchiectasis is a chronic infection of the lung airways leading to abnormal and permanent dilatation of the medium and smaller airways (bronchi and bronchioles). This allows mucous to accumulate and remain stagnant, and subsequently become infected leading to repeated lung infections.
Statistics on Bronchiectasis
In Australia the prevalence of this condition is 1.5% among children aged 15 and under. It has also been found recently that approximately 29 – 50% of patients with chronic obstructive pulmonary disease (COPD) have associated bronchiectasis.
Risk Factors for Bronchiectasis
Bronchiectasis can be congenital (the person is born with a predisposition to the disorder), or acquired (develops as a result of another process):
- Cystic fibrosis is an important cause of Bronchiectasis. There is increased viscid mucous secretion which remains stagnant, and is later infected.
- Primary ciliary dyskinesia is a disorder in which the lung’s cilia are not functioning properly. The cilia are little ‘hairs’ on the inside of a bronchus which sweep mucous up towards the trachea. In this disorder the cilia are ‘immotile’ i.e. not moving, thus allowing mucous to accumulate in the lower airways and get infected.
- Bronchiectasis may be initiated by certain infections, e.g. adenovirus, M. pneumoniae, measles, pneumonia, whooping cough, or tuberculosis .
- Exposure to chemical irritants (e.g. aspiration pneumonia, ammonia inhalation) can lead to airway inflammation and bronchiectasis.
- Disorders of immunological deficiency (HIV, hypogammaglobulinemia) or over-response (allergic bronchopulmonary aspergillosis) are associated with the disease.
- Chronic mechanical obstruction of a bronchus by a tumour or foreign body can also predispose a patient to bronchiectasis.
- Lung fibrosis (e.g. connective tissue disease, idiopathic pulmonary fibrosis) can increase the tension on the bronchi, leading to airway dilatation and “traction bronchiectasis”.
- In all of the above disorders, the ultimate end result is dilation of the smaller bronchi and bronchioles. Mucous remains stagnant in the smaller airways and subsequently gets infected, which leads to more damage to the wall of the bronchus, thus making it weaker and more dilated, initiating a vicious cycle.
Progression of Bronchiectasis
Symptoms have often been present for a number of years and are often initiated by an episode of pneumonia. The bronchial walls become inflamed, thickened and permanently damaged. More mucous accumulates in the dilated airways, predisposing the lungs to further bacterial infections. Persistent mucous production and airway obstruction leads to lung collapse and a reduction in the elastic forces holding the airways taught.
Common complications include: pneumonia, haemoptysis – coughing up blood (may be severe and life-threatening), abscesses travelling to other parts of the body (eg brain), respiratory failure, and right heart failure..
Symptoms of Bronchiectasis
If you are suffering from bronchiectasis the most likely symptoms that you would experience are:
- Chest pain
- There may also be other symptoms that you experience due to any underlying diseases you may have that put at risk of developing bronchiectasis.
Clinical Examination of Bronchiectasis
In order to establish a diagnosis of bronchiectasis your doctor will perform a full examination of your respiratory system. This will involve lying you onto the examination couch and initally looking your hands for evidence of disease. You will be expected to expose your torso such that the doctor can assess the degree of movement in your chest wall, the noises that your chest makes when percussed, and the quality of your breath sounds. The doctor may do additional examinations depending on the findings as well as your past medical history.
How is Bronchiectasis Diagnosed?
- A Full blood picture may show evidence of infection or immune deficiency.
- Sputum culture will usually grow the infective organism.
- Lung function tests
- Chest x-ray
- In severe cases, an ECG may be performed
- A High resolution CT is the test of choice to diagnose this condition
Prognosis of Bronchiectasis
The prognosis varies greatly on the causative mechanism. The advent of modern, effective antibiotic therapy and vaccination has greatly improved life expectancy. There is a 5 year mortality rate of 13% in people suffering from this condition. Poor prognostic factors are the volume of sputum produced as well as presence of infection with the organism pseudomonas aeruginosa.
How is Bronchiectasis Treated?
- Basic measures such as regular postural drainage and chest physiotherapy can help to clear sputum and provide symptomatic relief.
- Antibiotics should be prescribed on the basis of sputum culture and sensitivity testing. Prophylactic antibiotics and vaccination should be considered in patients who persistently produce purulent sputum.
- Bronchodilators may help in patients with asthma, ABPA or cystic fibrosis.
- Inhaled or oral corticosteroids may slow disease progression and are particularly useful for the treatment of ABPA.
- Surgery may be considered to control localised disease or severe haemoptysis.
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- King P, Holdsworth S., Freezer N., Holmes P., ‘Bronchiectasis’, Internal Medicine Journal, 2006, vol.36, pp. 729 – 737
- Angrill J, AgustoA C., Torres A, ‘Bronchiectasis’, Current Opinion in Infectious Disease, 2001, vol. 14, pp. 193 – 197
- Rosen M. J., ‘Chronic Cough Due to Bronchiectasis: ACCP Evidence-Based Clinical Practice’, Chest, 2006, vol. 129, pp.122 – 131
- Williams P, Gracey M, Smith P ‘Hospitalisation of Aboriginal and non-Aboriginal patients for respiratory tract diseases in Western Australia’, International Journal of Epidemiology,1997, vol. 26, no.4, pp.797-805