Practice Easily Missed?

Bronchiectasis

BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c2766 (Published 14 July 2010) Cite this as: BMJ 2010;341:c2766
  1. Nick H T ten Hacken, associate professor, pulmonary department,
  2. Thys van der Molen, professor, general practitioner department
  1. 1University Medical Center Groningen, University of Groningen, 9713 GZ Groningen, Netherlands
  1. Correspondence to: N H T ten Hacken n.h.t.ten.hacken{at}long.umcg.nl
  • Accepted 11 May 2010

Bronchiectasis is mostly an acquired bronchopulmonary disorder with abnormal thickening of the bronchial wall and dilation of central and medium sized bronchi, due to a vicious circle of transmural infection and inflammation with mediator release. Though many underlying conditions may induce or contribute to the development of bronchiectasis (table), it is idiopathic in about 50% of adults1 and 25% of children.2

Causes of and conditions associated with bronchiectasis1

View this table:

Case scenario

A 29 year old, non-smoking kindergarten teacher with mild asthma often visited her general practitioner with recurrent respiratory tract infections, which they both attributed to daily contact with her students. After seven courses of oral antibiotics in one year, the doctor requested sputum cultures. These showed Pseudomonas aeruginosa. Given this unusual result and her recurrent infections, he referred her to a lung physician, and high resolution computed tomography of her lung showed mild bronchiectasis, which was later found to be due to α1 antitrypsin deficiency.

How common is it?

The prevalence of bronchiectasis varies with time period and geography, due to differences in antibiotic prescription, availability of vaccinations, and prevalence of associated disorders. Additionally, the doctor’s alertness for bronchiectasis and the availability of sensitive diagnostic tools may affect reported prevalence. In the United States the prevalence of non-cystic fibrosis bronchiectasis among adults between 1999 and 2001 was estimated to be 51 per 100 000 population.3 The prevalence was higher among women than men (71 v 32 per 100 000) and increased markedly with age (4 per 100 000 for people aged 18-34 years v 272 per 100 000 for those aged 75 or over). In Australia the prevalence among Aboriginal children aged under 15 years was reported to be as high as 1470 per 100 000.4

In the United Kingdom, a full time, single handed practice of 2500 patients will have one or two patients with bronchiectasis, compared with 75 with asthma and 50 with chronic obstructive pulmonary disease.

Why is it missed?

Symptoms of bronchiectasis (such as chronic cough and sputum production) may be mild, particularly at the beginning. These symptoms may resemble asthma, chronic obstructive pulmonary disease, rhinosinus diseases, tracheobronchial infection, and gastroesophageal reflux, which are much more common than bronchiectasis in an average UK general practice. In an Australian cohort study, 40% of patients with bronchiectasis who developed chronic productive cough in adulthood also smoked.5 This may mislead the doctor to a diagnosis of chronic bronchitis induced by smoking. Basal crackles may suggest heart failure. Spirometry may show coexisting airway obstruction, leading to a misdiagnosis of chronic obstructive pulmonary disease instead of bronchiectasis. Chest x rays sometimes do not show mild bronchiectasis.

Why does it matter?

Patients with newly diagnosed bronchiectasis were found to have a poorer prognosis than those with asthma (matched for age and sex), but a better prognosis than those with chronic obstructive pulmonary disease.6 Over a follow-up period of 8.8 years, 25% of 372 Finnish patients with bronchiectasis died (mean age at the start of the follow-up was 56 years). In a Turkish cohort study in 98 patients with bronchiectasis, vaccination, scheduled visits to the doctor, and high body mass index seemed to improve survival.7

No controlled intervention studies have been done on the effect of an early diagnosis, a higher alertness of the general practitioner, or an active screening programme. Nevertheless, evidence based guidelines of the American College of Chest Physicians say that once bronchiectasis is discovered, looking for an underlying cause is important, as the results of diagnostic evaluation “may lead to treatment that may slow down or halt the progression of the disease.”8 The diseases that are described as underlying causes are among others listed in table 1.

How is it diagnosed?

Clinical features

Cough is present in 90% of the patients, and 76% produce sputum daily.9 Haemoptysis occurs in 51% of patients and tends to be recurrent. The usual abnormalities on chest examination are crackles (70%) and wheezes (34%).

Investigations

Requesting sputum cultures in patients with frequent respiratory infections may help to identify unusual infections that increase the suspicion of bronchiectasis, as the case scenario shows. Chest x rays may show linear markings, crowding, cystic spaces, and honeycombing.10 In a small study the sensitivity for chest x rays to detect bronchiectasis was found to be 88%, with a specificity of 74%,11 but other studies indicate that these figures will be less positive in mild bronchiectasis.

A normal chest x ray does not exclude bronchiectasis definitively. So, if there is a high clinical suspicion for bronchiectasis, a high resolution computed tomography scan of the chest should be considered. This scan has replaced contrast bronchography as optimal for diagnosis of bronchiectasis. Major features are airway dilation, lack of tapering (figure), thickening of the bronchial wall, mucopurulent plugs or debris, and cysts.12 The sensitivity of the scan is 82-97% and the specificity 99-100%.13

Specific tests to identify underlying causes or contributing conditions depend on the clinical setting and the patient’s history and age. Tests might include a white blood cell count and differentiation, IgG, IgG subclasses, IgM, IgA, total IgE, α1 antitrypsin levels, rheumatoid factor, and aspergillus serology.

Figure1

High resolution computed tomography scan of chest of a young non-smoking woman with mild bronchiectasis. White arrows indicate airway dilation and lack of tapering

How is it managed?

The evidence base for management is contentious, but expert consensus advocates advising patients who smoke to quit. Treat acute exacerbations with short courses (<4 weeks) of antibiotics targeted to likely organisms such as Pseudomonas aeruginosa, Haemophilus influenza, or Mycobacterium avium-intracellulare; or on basis of the results of sputum culture. Consider prolonged use of antibiotics (>4 weeks)14; although the criteria for doing so are not well established, we believe this might be beneficial in patients who often relapse (more than six times per year) or show progressive decline of lung function. The effectiveness of continuous mucolytics, anti-inflammatory agents, and bronchodilators is not clear but can be considered on individual basis.15 Physical therapy techniques that improve bronchial clearance of mucus are widely used, yet there is little evidence to support or refute them.16

Key points

  • Bronchiectasis may be easily missed because its clinical features may overlap with more common conditions, such as asthma, chronic obstructive pulmonary disease, rhinosinus disease, gastroesophageal reflux, and common upper and lower airway infections

  • General practitioners in the UK have one or two patients, on average, with bronchiectasis in their practice

  • Diagnosis is based on daily production of mucopurulent phlegm and chest imaging that shows dilated and thickened airways; high resolution computed tomography of the lung is the optimum diagnostic procedure

  • The diagnosis of bronchiectasis should lead to investigation and treatment of possible causes and associated conditions

  • Treat acute exacerbations promptly with short courses (less than four weeks) of antibiotics

Notes

Cite this as: BMJ 2010;341:c2766

Footnotes

  • This is a series of occasional articles highlighting conditions that may be commoner than many doctors realise or may be missed at first presentation. The series advisers are Anthony Harnden, university lecturer in general practice, Department of Primary Health Care, University of Oxford, and Richard Lehman, general practitioner, Banbury. If you would like to suggest a topic for this series please email us (easilymissed.bmj{at}bmjgroup.com).

  • Contributors: NHTH and TvdM both did the research and revision; NHTH wrote the first version. NHTH is guarantor.

  • Funding: No additional funding.

  • Competing interests: All authors have completed the Unified Competing Interest form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare (1) no support from any company for the submitted work; (2) no relationships with any companies that might have an interest in the submitted work in the previous 3 years; (3) their spouses, partners, or children have no financial relationships that may be relevant to the submitted work; and (4) no non-financial interests that may be relevant to the submitted work.

  • Provenance and peer review: Not commissioned; externally peer reviewed.

  • Patient consent not required (patient anonymised, dead, or hypothetical).

References