Elsevier

Medicine

Volume 40, Issue 5, May 2012, Pages 267-272
Medicine

Bronchiectasis
Bronchiectasis

https://doi.org/10.1016/j.mpmed.2012.02.003Get rights and content

Abstract

Bronchiectasis is defined as irreversible, abnormal dilatation of one or more bronchi, with chronic airway inflammation, associated chronic cough and sputum production, recurrent chest infections and airflow obstruction. The diagnosis of bronchiectasis is made clinically and confirmed by high-resolution computed tomography (HRCT) of the chest. Patients with a diagnosis of bronchiectasis should be referred to a specialist unit for investigation and management. This article deals with non-cystic fibrosis (CF) bronchiectasis. Bronchiectasis is a common structural endpoint that can be reached by several pathological routes from foreign body obstruction to post-infectious damage (tuberculosis), genetic defects (cystic fibrosis), abnormal host defence (ciliary dyskinesia and hypogammaglobulinaemia) and autoimmune disease (rheumatoid arthritis and ulcerative colitis). About half of all cases are called idiopathic since no known underlying cause is identified following detailed investigation. These patients typically have bilateral, predominantly lower lobe disease, and chronic rhinosinusitis. The underlying pathogenesis of bronchiectasis is not known. Innate and adaptive immune mechanisms have been implicated. There appear to be two stages to the disease process: an initial insult followed by a continuing inflammatory process encompassing recurrent infection and progressive lung damage. Abnormalities in immune regulation may predispose to bronchiectasis, both at the time of the initial insult that sets off the disease and during the on-going inflammatory process that ends in progressive lung damage. Immunogenetic evidence suggests a link between the extent of natural killer (NK) cell activation and disease susceptibility. Further evidence for adaptive immune mechanisms includes a genetic association with HLA-DR1, DQ5 and increased susceptibility to idiopathic bronchiectasis.

Section snippets

Definition

Bronchiectasis is a common structural endpoint with many causes, ranging from foreign body obstruction to post-infectious damage (tuberculosis), genetic defects (cystic fibrosis), abnormal host defence (ciliary dyskinesia and hypogammaglobulinaemia) and autoimmune disease (rheumatoid arthritis and ulcerative colitis). There is irreversible abnormal dilatation of one or more bronchi, with chronic airway inflammation, associated chronic cough and sputum production, recurrent chest infections and

Epidemiology

The prevalence of bronchiectasis is not known.1, 2 High-resolution computed tomography (HRCT) has led to increased detection, particularly in patients who in the past might have been undiagnosed or classified as chronic obstructive pulmonary disease (COPD). One study found that 50% of patients with a diagnosis of COPD had evidence of bronchiectasis on HRCT thorax.4 HRCT allows a diagnosis of bronchiectasis in mild cases. Severe bronchiectasis is becoming less common in developed countries,

Pathophysiology

The bronchial airways are weakened by destruction of elastic and muscle layers, leading to abnormal dilatation; this allows mucus to accumulate and favours bacterial infection. The damaged epithelium lacks ciliated cells, which precludes the effective removal of excess mucus. This structural damage promotes chronic microbial colonization and predisposes to recurrent bacterial infections.1, 2

The Reid classification categorizes bronchiectasis according to pathological and radiological appearance:

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Causes of bronchiectasis

Bronchiectasis appears to be a structural endpoint with many different causes and associations (Table 2).1, 2, 3 However, in about half of all cases no underlying cause is found.12 These patients typically have bilateral, predominantly lower lobe disease, chronic rhinosinusitis, profound tiredness and difficulty concentrating; they are more commonly female and present with chronic cough and sputum production in adult life.

Clinical features

Symptoms: patients with mild disease may be asymptomatic except during clearly defined exacerbations. The most common symptoms are chronic cough and daily sputum production (typically tenacious and mucopurulent), intermittent haemoptysis, foetor and pleuritic chest pain (usually associated with infective exacerbations), breathlessness, and wheeze. Tiredness with poor concentration, low-grade fever and chronic rhinosinusitis are also clinical features of the disease. Exacerbations, caused by

Diagnosis

The diagnosis is usually clinical, confirmed with HRCT of the chest.

Investigations

Investigations should aim to confirm the diagnosis, identify any treatable cause of the bronchiectasis and optimize management to reduce the frequency and severity of exacerbations and lung damage (Table 3).1, 2

Chest radiographs are insensitive at detecting bronchiectasis (at about 50%) making HRCT chest the investigation of choice. HRCT is 97% sensitive at detecting disease. Chest radiographs may show ‘tramlines’, indicating thickened airways, ‘ring shadows’, and segmental or lobar collapse.

Management

The goal of treatment is to prevent or slow down progressive lung damage. This entails treating any predisposing medical conditions, controlling symptoms, reducing the frequency and severity of infective exacerbations, and dealing with complications early. If bronchiectasis is suspected clinically, or confirmed by HRCT, the patient should be referred for further investigation and specialist management.

Every patient should have a self-management plan for exacerbations and intercurrent

Physiotherapy

Physiotherapy is fundamental in the management of bronchiectasis, to reduce the severity and progression of disease. All patients should be taught techniques that promote airway clearance on a daily basis. These include:

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    postural drainage

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    active cycle-of-breathing techniques

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    cough augmentation (using flutter valves)

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    exercise regimens (to prevent general deconditioning).

During acute infective exacerbations, the physiotherapist assists in clearing tenacious sputum.

Airflow obstruction should be

Underlying conditions

The identification and treatment of predisposing medical conditions is important. For example, treating reflux if there is evidence of recurrent aspiration. CVID or hypogammaglobulinaemia is the most common immune deficiency linked to bronchiectasis and these patients benefit from intravenous immunoglobulin therapy, administered every 3 weeks under the guidance of a clinical immunologist. There are no specific treatments for primary ciliary dyskinesia. Attention should focus on the importance

Acute infective exacerbation

Patients present with increased sputum volume, breathlessness, cough, malaise, and pleuritic chest pain. Antibiotic therapy should be altered based on microbiological results. Common bacterial pathogens causing infective exacerbations are H. influenzae, H. parainfluenzae and S. pneumoniae (Table 1). First-line therapy, if there is no history of P. aeruginosa, should be 14 days’ treatment with β-lactam antibiotics (amoxicillin) or, where β-lactamase-producing strains are suspected, co-amoxiclav.

Prophylactic therapy

Prophylactic antibiotics should be considered in patients with frequent relapses necessitating courses of oral antibiotics (more than six per year), or hospital admissions for intravenous antibiotics (more than twice a year), or patients who relapse within 1 month of appropriate intravenous antibiotic therapy without an explanation.21 Initially, these patients should be investigated to establish if there is an underlying cause. This might include HRCT, lung function tests, sputum microscopy,

Eradication therapy for P. aeruginosa

P. aeruginosa is associated with a poorer prognosis in bronchiectasis, with more rapid decline in lung function.22 In view of this, some units attempt to eradicate P. aeruginosa at first isolation to prevent chronic colonization. It remains to be seen if this approach is beneficial. In our unit, patients are initially treated with a 2-week course of ciprofloxacin, assuming that the organism is sensitive. If P. aeruginosa is recultured following this, the patient is admitted for a 10-day course

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