Bronchiectasis: clinical review

The causes of bronchiectasis, investigations to conduct, managing exacerbations and when to refer.

Section 1: Epidemiology and aetiology
Section 2: Making the diagnosis
Section 3: Managing the condition
Section 4: Prognosis
Section 5: Evidence base


Section 1: Epidemiology and aetiology

Bronchiectasis is a chronic disease resulting from the abnormal and permanent distortion of one or more of the bronchi. The airways are abnormally dilated and become a collecting point for airway secretions, which are produced in excess.

The epithelium is damaged, leading to loss of ciliated cells, which impairs clearance of these secretions.

Stationary mucus acts as a breeding ground for bacteria and is a source of recurrent and persistent bacterial infections. These lead to further inflammation, which in turn causes more damage to the bronchial walls — a vicious cycle of inflammation, damage and infection.

There are four radiological types of bronchiectasis, often varying in clinical severity:

  • Cystic (saccular) is a severe form of bronchiectasis characterised by very large volumes of sputum production and frequent infections. This is far less common now in the developed world than it was in the past.
  • Cylindrical is the most common type. It generally runs a milder course and commonly affects the lower lobes bilaterally.
  • Varicose bronchiectasis, in which the bronchial walls have a beaded appearance because of scarring, causing constriction superimposed on dilation.
  • Traction bronchiectasis is found in fibrotic lung diseases such as sarcoidosis and fibrosing alveolitis as airways are pulled apart by the fibrotic process. Generally this is not associated with recurrent infections and is a ‘dry bronchiectasis’.

Prevalence
One in 1,800 UK hospital admissions is a result of bronchiectasis as the primary condition, and bronchiectasis patients occupy around one in every 1,000 hospital bed days.1

Data from UK primary care suggests an incidence of 1/1000 or higher in older age groups.2

Aetiology
Up to 50% of cases of bronchiectasis are idiopathic, with no identified underlying cause. This aetiology may have better outcomes than bronchiectasis that is associated with COPD or rheumatoid arthritis. There are some known causes of bronchiectasis (see box 1) and several conditions have been associated with bronchiectasis without a clear understanding of the aetiology.3

COPD and asthma are common comorbidities in patients with bronchiectasis but it is unclear if they are causal factors.

Box 1: Causes of bronchiectasis

Infection: Severe bacterial respiratory tract infections* such as pneumonia or tuberculosis

Abnormal mucus clearance: Primary ciliary dyskinesia, cystic fibrosis*, Young's syndrome

Immune*: Hypogamma-globulinemia, common variable immunodeficiency, HIV

Inflammatory: Inhalation of corrosive gas or aspiration of gastric contents into the lungs*

Excessive immune response: Rheumatoid arthritis*, allergic bronchopulmonary aspergillosis*, lung transplant rejection*

Congenital: Yellow nail syndrome, deficiency of structural elements of the bronchial wall (e.g. Marfan's syndrome, Ehlers-Danlos syndrome)

Mechanical obstruction: Obstruction by a foreign body* — most common in children, tumour, or stenosis in association with recurrent infection

*Conditions or causes that are potentially treatable


Section 2: Making the diagnosis

Bronchiectasis is characterised by chronic sputum production with susceptibility to lower respiratory tract infections. Infections may be bacterial, viral, or both. There may be chronic bacterial infection causing daily purulent sputum production.

Exacerbations are usually associated with an increase in volume of sputum and purulence, although sputum production can also decrease as it becomes more viscous and difficult to clear.

Patients become breathless on exertion and may experience chest discomfort. Many patients have associated symptoms of rhinosinusitis.

There may be coarse crackles heard over the affected area (these can also be heard in stable patients). Wheezes occur secondary to airflow obstruction. There may be squeaks, which indicate small airways disease.

Investigations
The diagnosis is confirmed on CT scanning. The defining characteristic of bronchiectasis is bronchial dilation, with the internal diameter of the bronchial lumen greater than that of the adjacent artery.

Chest X-rays are an insensitive screening test for bronchiectasis. A normal chest X-ray can be seen in up to 20% of cases of moderate bronchiectasis, so does not exclude this diagnosis. However, a chest X-ray is useful for ruling out other pulmonary conditions.

Patients who have atypical features, deteriorating symptoms, or are young, should be investigated to determine the aetiology and severity of their condition.

Sputum analysis for colour and volume, measured over a 24-hour period, can be helpful in distinguishing stable disease from an exacerbation.

Lung function testing is useful for monitoring disease severity because it can be repeated easily. Lower FEV1 measurements correlate with greater extent of bronchiectasis.

Advanced airflow obstruction may be seen in severe bronchiectasis, but there may also be restrictive or normal patterns.

Patients with severe bronchiectasis may develop right heart failure, which is a poor prognostic feature. Echocardiography should be performed if there is concern about cardiac involvement.

Aspergillus allergy and non-TB mycobacterial (NTM) infection can cause bronchiectasis, or complicate pre-existing disease leading to deterioration in a previously stable patient.

All problematic patients should be thoroughly investigated to identify any treatable cause of bronchiectasis. This will often require referral to a chest specialist.

Box 2. Key features in the history and examination

Ask about:

  • Cough
  • Volume and colour of sputum production
  • Haemoptysis
  • Energy levels/fatigue
  • URTI: blockage, running, postnasal drip, facial pain
  • Chest pain
  • Frequency of exacerbations
  • Shortness of breath

Features of an exacerbation:

  • Increased breathlessness
  • Increased sputum production
  • Sputum purulence
  • Pyrexia, often low grade
  • Pleuritic chest pain (this is a serious complication as it restricts the cough)
  • Minor haemoptysis (major haemoptysis is rare)

Key features in examination:

  • Crackles over affected areas
  • Obstructive spirometry, often with little reversibility
  • Clubbing is not usually present (cystic bronchiectasis is now rare because of improvements in treatment)
  • The nose may be obstructed with evidence of inflammation
Box 3. Suitable investigations in the community
  • Blood investigations: FBC with white cell differential; CRP; routine biochemistry; aspergillus IgG and RAST; rheumatoid factor and other auto-antibodies if clinically indicated; protein electrophoresis strip; immunoglobulin levels
  • Chest radiograph: PA and lateral
  • Spirometry
  • Sputum culture and sensitivity
  • Sputum smear and culture for acid-fast bacilli

Section 3: Managing the condition

Stable disease
The aim of management is to reduce symptoms, limit exacerbations, preserve lung function and improve quality of life.

The mainstays of treatment are daily physiotherapy to drain the affected areas and improve the efficiency of clearing sputum, and antibiotics to treat infection and reduce inflammation.

All patients should be reviewed by a specialist chest physiotherapist for training in active cycle breathing technique and devices such as the Flutter mucus clearance device. These have similar outcomes to traditional postural drainage but are easier for patients to master.4

Bronchodilators
There is a role for bronchodilator therapy and inhaled hyperosmolar agents, such as nebulised hypertonic 7% saline, as adjuncts to physiotherapy.5 Inhaled beta-2 agonists and/or anticholinergics may be used before chest physiotherapy to minimise bronchial hyper-reactivity, and can also help to relieve breathlessness.

There is limited evidence for the use of oral mucolytics but these may be worth trying in select populations.

Use of high-dose inhaled corticosteroids (fluticasone 500microgram twice daily or beclometasone 750microgram twice daily) have shown a reduction in 24-hour sputum volume and improvement in quality of life but no impact on FEV1 or exacerbation frequency.6 Routine use of these in bronchiectasis is discouraged, unless there is significant comorbid asthma or COPD.

Antibiotic therapy
Long-term continuous antibiotic therapy, which can be given as oral, nebulised or planned IV courses, may be indicated in patients having frequent exacerbations that are impacting on their quality of life. See table 1.

These patients usually have persistent chronic infection, often with pseudomonas species, and it is thought that the antibiotics reduce inflammation by decreasing the bacterial population of the airways. There is a risk that antibiotic prophylaxis will encourage resistance of the lung flora. So long-term antibiotic therapy must be limited to patients who, despite optimum medical management, continue to have frequent exacerbations.

Recently there has been clear evidence that long-term macrolides reduce exacerbations in bronchiectasis.7 It is recommended that these are started under secondary care guidance and preferably after NTM infection has been excluded.

Surgery
Surgery may be an option if the bronchiectasis is localised to one area of the lung. This could be considered if medical management has not controlled symptoms and lung function is adequate. Because most cases of tubular bronchiectasis are bilateral, surgery is rarely used.

Bilateral lung transplantation can be used in atypical cases with severe life-threatening disease in younger patients.

Vaccination
Influenza and pneumococcal vaccination are recommended as per national schedules.

Exacerbations
Fresh sputum cultures should be sent for microbiological culture. But because sputum culture can take up to five days, prompt empirical antibiotic therapy should be started, based on previous sputum microbiology (if available).

Treatment should be adjusted if there is no clinical improvement and should be guided by culture and sensitivity results. Antibiotics should be continued for 14 days according to BTS guidelines.8

Increased chest physiotherapy at times of exacerbation will help to clear secretions and the patient should be advised to keep well hydrated. Patients may also require a short course of oral prednisolone in severe exacerbations and/or modification of their bronchodilator therapy.

Table 1: Antibiotics commonly used in bronchiectasis
Name Dosage and duration Comment
Non-pseudomonas
Co-amoxiclav 625mg three times daily 10-14 days Many Haemophilus influenzae, and most Moraxella catarrhalis, produce beta-lactamase so are resistant to amoxicillin.
Doxycycline 200mg once daily first day, 100mg once daily 13 days 100mg twice a day in severe cases. Warn patient of photosensitivity.
Azithromycin 500mg once daily 14 days
Pseudomonas
Ciprofloxacin 750mg twice a day 14 days 500mg twice a day if higher dose not tolerated.
Azithromycin 500mg once daily 14 days Treat with a further 250mg once in severe cases; does not kill pseudomonas but reduces pathogenicity and inflammation.
Cotrimoxazole 960mg twice daily 14 days Does not kill pseudomonas but may reduce pathogenicity and inflammation.

When to refer
Most patients with mild bronchiectasis can be managed in general practice. Physiotherapy training is a key aspect of management, and referral for this within primary care should be undertaken.

It is important that all young patients are referred for investigations into possible underlying causes, particularly cystic fibrosis or immunodeficiency.

Referral for specialist review should be considered if a patient is having more than three exacerbations per year or has pseudomonas.

Patients with associated conditions such as rheumatoid arthritis or COPD would also benefit from specialist opinion.


Section 4: Prognosis

Prognosis varies widely, depending on how widespread and severe the bronchiectasis, and the presence of other underlying disorders.

Severity scores are now available, for example the Bronchiectasis Severity Index9 available at: www.bronchiectasisseverity.com.

High-risk groups are older patients, those with pseudomonas, severe airflow impairment, widespread radiological extent and previous hospitalisation.

Most patients with bronchiectasis have a reasonable outlook with on average one to three exacerbations per year. Treatment, in particular antibiotic treatment for any infection or regularly when needed, keeps most patients reasonably well.

Important! Most patients with bronchiectasis have an average of one to three exacerbations per year.

Patients with comorbid conditions such as COPD, and patients with complications such as pulmonary hypertension or cor pulmonale, tend to have a worse prognosis.

A life-threatening bleed from a damaged airway may occur, but is rare.


Section 5: Evidence base

Guidelines
Pasteur MC, Bilton D, Hill AT et al. British Thoracic Society guideline for non-CF bronchiectasis. Thorax 2010;65 Suppl 1:i1-58.

Online
www.bronchiectasis.info - A support forum for patients with bronchiectasis

  • Dr Anthony De Soyza is an Honorary consultant physician, Freeman Hospital, Senior lecturer in respiratory medicine, Newcastle University UK

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References

  1. Department of Health. Hospital edipsode statistics. Avaialble from:http://www.hesonline.nhs.uk (accessed 5 September 2016).
  2. Quint JK, Millett ER, Joshi M et al. Changes in the incidence, prevalence and mortality of bronchiectasis in the UK from 2004 to 2013: a population-based cohort study. Eur Respir J 2016; 47(1) :186-93.
  3. Pasteur M, Helliwell S, Houghton S et al. An investigation into causative factors in patients with bronchiectasis. Am J Respir Crit Care Med 2000; 162(4 Pt 1): 1,277-84.
  4. Thompson C, Harrison S, Ashley J et al. Randomised crossover study of the Flutter device and the active cycle of breathing technique in non-cystic fibrosis bronchiectasis. Thorax 2002; 57: 446-8.
  5. Kellett F, Redfern J, Niven RM. Evaluation of nebulised hypertonic saline (7%) as an adjunct to physiotherapy in patients with stable bronchiectasis. Respir Med 2005; 99(1): 27-31.
  6. Tsang K, Tan K, Ho P et al. Inhaled fluticasone in bronchiectasis: a 12-month study. Thorax 2005; 60: 239-43.
  7. Wong C, Jayaram L, Karalus N et al. Azithromycin for prevention of exacerbations in non-cystic fibrosis bronchiectasis (EMBRACE): a randomised, double-blind, placebo-controlled trial. Lancet 2012; 380(9842): 660-7.
  8. Pasteur MC, Bilton D, Hill AT et al. British Thoracic Society guideline for non-CF bronchiectasis. Thorax 2010;65 Suppl 1:i1-58.
  9. Chalmers JD, Goeminne P, Aliberti S et al. The bronchiectasis severity index. An international derivation and validation study. Am J Respir Crit Care Med 2014; 189(5):576-85.

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