Bronchiectasis

Bronchiectasis is an abnormal and permanent dilatation and distortion of the bronchi.¹ It may be widespread in the lungs or affect just part of the lungs or just one lobe. The airways are inflamed and easily collapse, thus impairing air flow and drainage of secretions. A large amount of mucus accumulates in the lungs. The mucus collects bacteria, predisposing to frequent and often severe lower respiratory tract infections. Bronchiectasis usually develops after a series of lung problems (e.g. childhood infections, problems with lung structure, tuberculosis, and cystic fibrosis).

Bronchiectasis was first described by Laennec in 1819 but Sir William Osler gave a more thorough description in the late 19th century.

• Although the disease is still caused by infection, there has been much change in its nature due to treatment with antibiotics and immunisation.
• Bronchiectasis used to start in the first decade of life but is rarely seen so early now except in cystic fibrosis.
• The severity used to be classified according to the volume of sputum but this is largely superseded by radiological appearance, especially CT scan.

• Usually starts in adult life.
• Women tend to be more severely affected than men.²

Risk factors

The disease is caused by infection but there are certain conditions that facilitate such infection, so as to cause damage to the lungs:

• Cystic fibrosis
• Infection that has not been properly treated, measles, pertussis, respiratory syncytial virus in children
• Bronchial obstruction from lymph nodes or inhaled foreign bodies. Right middle lobe syndrome is a specific type of bronchial obstruction that may lead to bronchiectasis. It results from an abnormal angle of the lobar bronchus at its origin, causing obstruction, subsequent infection, and later bronchiectasis.
• Impaired immunity, especially B-cell deficiency causing agammaglobulinaemia. Examples include Bruton's agammaglobulinaemia, AIDS.
• Alpha-1-antitrypsin deficiency
• Conditions associated with impaired cilial function in the respiratory tract
• Broncho-pulmonary aspergillosis
• Some autoimmune diseases, e.g. rheumatoid arthritis, Sjogren's disease
• Following exposure to toxic gas

Smoking does not appear to be an independent risk factor but if the patient smokes it is important to stop.

• 90% have a chronic daily cough and three quarters produce mucopurulent sputum. The volume of sputum tends to be particularly high in patients with cystic fibrosis.
• More variable features include dyspnoea, pleuritic chest pain, wheezing, haemoptysis, fever, weakness, and weight loss. Weight loss tends to suggest advanced disease.
• Dry bronchiectasis without much sputum but occasional haemoptysis can occur. It tends to follow tuberculosis and to involve the upper lobes.
• There is usually a history of multiple exacerbations caused by infection with the need for antibiotics. This is associated with an increased volume of sputum that becomes green, purulent and perhaps smells foul.
• Such exacerbations often occur with increased fatigue and malaise, increased pleuritic pain and wheeze with shortness of breath.
• Over half, and possibly rather more, have haemoptysis. This can erode a pulmonary artery and cause very significant bleeding. More often the patient complains of flecks of blood in the sputum.
• Patients with extensive bronchiectasis often have dyspnoea but it is difficult to determine how much may be due to co-existent disease.

Signs

• The patient may look thin, if weight has been lost.
• If airways obstruction is marked there may be use of accessory muscles of respiration and breathing through pursed lips.
• Cyanosis is unlikely unless there is other disease.
• There may be clubbing of the finger nails in more severe cases. It is not a common finding.
• Crackles and rhonchi are a non-specific sign that may occur over affected areas and there may be general rhonchi from narrowed airways and obstruction by sputum.
• In very advanced cases there could be cor pulmonale.

• Blood tests are non-specific but may confirm the presence of infection. They may also help confirm or refute one of the predisposing diseases if it is suspected. Polycythaemia only occurs in very advanced cases.
• Sputum culture should be performed, especially when there is reason to suspect that infection is causing an exacerbation. Pseudomonas aeruginosa is quite commonly cultured. Unexpected findings may include hyphae of aspergillus or Mycobacterium tuberculosis.
• In children or young people cystic fibrosis must be considered.
• Chest x-ray with lateral is a basic requirement but tomography.
• CT may be required to show the exact extent of the disease and the distribution may give a clue to aetiology.
• High resolution CT has a very high sensitivity and specificity for diagnosis.³ It has now replaced bronchography.
• Pulmonary function tests are required to assess the degree of damage and to monitor progress.

• Damaged lung cannot be repaired and so the basis of management is to prevent or at least retard further deterioration. If there is a specific disease that predisposes to the bronchiectasis it may need treatment.
• Treat exacerbations of infection promptly and energetically. The value of long-term antibiotics is debatable.⁴
• Physiotherapy is important to help drainage of sputum. This may include teaching postural drainage and teaching a spouse percussion to aid clearance of mucus. Although there is evidence of the benefits of inspiratory muscle training, there is no evidence of effect for other types of physical training (including pulmonary rehabilitation) in patients with bronchiectasis.⁵
• If the patient smokes this must be stopped and help to stop smoking may be offered. Passive smoking should also be avoided
• Immunisation against influenza and pneumococcus.
• Bronchodilators may offer some benefit to some patients where airways hyper-reactivity causes bronchospasm although a Cochrane review found that the validity of this approach had not been addressed.⁶
• In acute infection oral steroids may reduce damaging inflammatory response but there is no good evidence for their use.⁷ However regular use of inhaled corticosteroids may improve lung function.⁸
• In some cases, especially advanced or complicated disease, surgical resection of damaged lung may be beneficial.⁹
• There is inadequate evidence to advocate mucolytics.¹⁰
• The use of oxygen therapy in COPD may need to be considered.
• Lung transplantation may need to be considered if pulmonary function is very poor with FEV₁ below 30% of predicted.¹¹

• Repeated infection and deteriorating lung function
• Empyema
• Lung abscess
• Amyloidosis (rare)

• Before antibiotics, death would occur within 5 years but now with aggressive therapy the outcome is much better.