Bronchiectasis describes the irreversible and abnormal dilatation of the airways.
It normally results from the inflammatory destruction of the elastic and muscular components of the airways. This leads to abnormally dilated airways, persistent sputum production with ineffectual clearance and recurrent chest infections.
Bronchiectasis commonly occurs secondary to cystic fibrosis though this is often considered and covered separately.
In 2012 it was estimated that 210,000 people in the UK had bronchiectasis.
The figures for prevalence and incidence vary widely by source as the condition often goes unrecognised or undiagnosed.
Data from the British Lung Foundation indicates females are affected more than males. In 2012 they estimated that 379 females and 281 males had bronchiectasis per 100,000. The condition becomes more common with advancing age with around 60% of cases diagnosed over the age of 70.
There are a wide range of causes of bronchiectasis though up to 40-50% of cases will be idiopathic in nature.
Generally speaking bronchiectasis results from infective insults combined with defective mucociliary clearance, airway obstruction or impaired host immunity.
Infective pathogens promote an inflammatory response involving the activation of neutrophils and release of inflammatory mediators - this results in damage to elastic and muscular components of the airway resulting in dilated airways. The abnormal dilatation of the airways further predispose patients to infections. This leads to a cycle of infection and worsening bronchiectasis.
Immunodeficiencies predispose patients to infection. Recurrent infective insults, combined with a poor host immune response, increase the risk of developing bronchiectasis. Causes may be primary or secondary:
Airway obstruction can lead to bronchiectasis. Foreign bodies (particularly in children), mucus plugging, stenosis, tumours or lymph nodes can all be responsible.
Ciliated epithelial cells are essential to the normal function of the airways, progressively clearing them of sputum. Dysfunction leads to mucus accumulation and predisposes to recurrent infection. Causes include:
Cystic fibrosis causes dehydration and depletion of airway surface liquid - which is key to the normal function of cilia. This is discussed in more detail in our Cystic fibrosis notes.
Patients often present with persistent sputum production associated with a chronic cough.
In adult patients, bronchiectasis should be suspected in those with persistent purulent/mucopurulent sputum production and a persistent cough. Sputum cultures that return P. aeruginosa is also highly suspicious for bronchiectasis. Features may also reflect the underlying aetiology (discussed above).
Of course there is cross-over between the features of bronchiectasis and other pulmonary conditions. Clinicians must consider other differentials including asthma, COPD and malignancies (which themselves may cause bronchiectasis).
The clinical course of bronchiectasis may be interrupted by acute infective exacerbations. The abnormal and dilated airways have impaired ability to clear sputum and pathogens from the lungs resulting in increased risk of infection.
Acute infective exacerbations present with a worsening of chronic features (dyspnea, cough and sputum production) as well as those of systemic infection such as fever and malaise.
CT chest is the the diagnostic modality of choice in patients with suspected bronchiectasis.
The British Thoracic Society (BTS) guidelines: Bronchiectasis in Adults (2018) advise baseline chest x-ray and thin section CT chest for patients with suspected bronchiectasis:
Investigations aim to identify the underlying cause of bronchiectasis.
A detailed history and examination must be completed for all patients. This should aim to identify features that could indicate an underlying aetiology. The British Thoracic Society (BTS) guidelines: Bronchiectasis in Adults (2018) outlines important investigations to order or consider.
In appropriate patients (e.g. young, indicative history) testing for cystic fibrosis should be completed.
In patients with features of arthritis, vasculitis or connective tissue disease consider rheumatoid factor, anti-cyclic citrullinated peptide, antinuclear antibodies (ANA) and anti-neutrophil cytoplasmic antibodies.
A bronchoscopy should be considered in people with localised disease on imaging to check for a local obstruction - e.g foreign body.
Testing for primary ciliary dyskinesia can be sought if the patient exhibits suggestive features (see aetiology section above).
The goals of treatment are to educate the patient on their condition, treat any underlying cause (where possible) and reduce the number of exacerbations they suffer.
All patient should receive review from both a respiratory clinician and respiratory physiotherapist. Damage to the lung may not be reversed however the progress of disease can be slowed or stopped.
Education and support should be offered and patients given a self management plan. The yearly flu vaccine should be offered in addition to help with smoking cessation, diet and exercise.
All patients should be taught airway clearance technique by a respiratory physiotherapist. There are a number that may be taught such as active cycle of breathing techniques. Gravity assisted positing can be used as an adjunct to airway clearance techniques.
Mucoactives are agents that help the clearance of mucus from the airways. They are typically indicated in patients with ongoing exacerbations (e.g. > 3 / year) despite optimal conservative measures.
Isotonic and hypertonic saline may be used and have been shown to improve quality of life. Oral carbocisteine may be trialled and continued if it offers a benefit.
Recombinant human DNase is not recommended in adults with bronchiectasis
Patients with recurrent exacerbations (> 3 per year) despite education, treatment of underlying causes, physiotherapy (+/- mucoactives) should be considered for long term antibiotics. Treatment depends whether or not the patient is colonised by P. aeruginosa:
Of note macrolide antibiotics should not be used in patients with non-tuberculous mycobacterium where it can breed resistant strains.
Bronchodilators can be used in patients with coexisting asthma/COPD or in those with significant breathlessness.
Lung resection may be considered in patients with localised disease with uncontrolled symptoms. Lung transplant may be considered, generally in patients aged 65 or younger with an FEV1 < 30% and clinical instability or rapidly deteriorating lung function despite medical intervention. Other indications include complications such as massive haemoptysis and pulmonary hypertension.
Patients require prompt clinical assessment and basic investigations including CXR, blood tests, sputum and blood cultures where indicated.
Depending on the severity of the illness, co-morbidities and psychosocial factors care may be as an inpatient or outpatient. Anyone presenting with features of sepsis should be managed with the sepsis 6 principles in mind and have an early senior review.
Antibiotic therapy may guided by previously obtained cultures and updated once the results of contemporary cultures have been returned. Inpatients should have review by respiratory physiotherapy to ensure optimal airway clearance.
Bronchiectasis may be complicated by a number of conditions.
Patients with bronchiectasis have been shown to have a higher incidence of ischaemic heart disease, depression and anxiety when compared to the general population.
The prognosis of bronchiectasis is closely linked with the underlying severity of disease.
Patients with mild disease may have a life-expectancy that is equal to the general population. Those with more severe disease tend to have a reduced life expectancy. NICE CKS quote that the age adjusted mortality is twice as high in those with bronchiectasis. Additionally they are more likely to suffer with the complications described in the chapter above.
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