Bronchiectasis

What is bronchiectasis?

Bronchiectasis is derived from the Greek words:

Bronckos – airway

Ectasis – widening

It is a chronic lung condition, defined as the abnormal, irreversible dilatation of the bronchi,

where the elastic and muscular tissue is destroyed by acute or chronic inflammation and

infection. This damage impairs the natural drainage of bronchial secretions which can

become chronically infected resulting in mild to moderate airway obstruction. Unless

appropriately managed, the combination of infection and chronic inflammation, results in

progressive lung damage.

Depending on the aetiology, specific lobes or both lungs can be affected.

Although the site of damage, diagnosed by a high resolution computed tomography (HRCT)

scan, is the larger airways, it is likely that the disease manifests itself in the smaller airways,

which is not detected by an HRCT scan. Many patients may have experienced symptoms for

many years before a diagnosis is confirmed.

Bronchiectasis can be classified into the following forms morphologically (all three forms

may be present in the same patient):

Cylindrical bronchiectasis: bronchi are enlarged and cylindrical.

Varicose bronchiectasis: bronchi are irregular with areas of dilatation and

constriction.

Saccular or cystic: dilated bronchi form clusters of cysts. This is the most severe form

of bronchiectasis and is often found in patients with cystic fibrosis

Diagnostic features on HRCT scan include:

The internal diameter of a bronchus is wider than it’s adjacent pulmonary artery

The bronchial walls may be thicker due to sputum retention

The bronchi do not taper

Bronchi observed in the outer 1-2 cm of the lung fields

Conversely, it is possible to have evidence of bronchiectasis on HRCT without clinical

symptoms. This may be due to a process involving lung parenchyma with secondary fibrosis

and retraction of the structures supporting the airway. This is called traction bronchiectasis

and can be seen in patients with conditions such as interstitial lung disease.

Pathophysiology

Paul King is writing a section here

Prevalence of bronchiectasis

Bronchiectasis can affect anyone at any age but occurs more frequently in less affluent

communities and in Indigenous communities.

Prevalence data varies considerably throughout the world with a very high incidence in the

Indigenous populations of New Zealand and Australia. A study of Central Australian

Aboriginal children found a prevalence of 1,470/100,0001. In New Zealand, the reported

prevalence is 3.7 per 100,000 population, but this varies according to ethnicity (Twiss

2005)2.

In the United States, a 2005 study estimated a range from 4.2/100,000 in the 18-34 years

age group to 272/100,000 in those over 75 years of age3. More recent information has

shown 1106 cases per 100,000 population over an eight-year period4.

A study in the UK5 found prevalence in men was 227/100,000, and 309/100,000 in women

with prevalence highest in patients over 60 years of age.

Groups at risk include those with established lung disease such as chronic obstructive

pulmonary disease (COPD). Bronchiectasis has been identified in up to 50% of these

patients. It is likely that many people with chronic respiratory symptoms due to

bronchiectasis remain undiagnosed.

A family history of cystic fibrosis, Kartagener’s Syndrome and primary ciliary dyskinesia

(PCD) is important as these conditions share an autosomal recessive inheritance pattern and

therefore may increase the risk of bronchiectasis.

The prevalence of severe cystic bronchiectasis has decreased because of the introduction of

vaccination against childhood infections, improved socioeconomic conditions and the

availability of antibiotics, but in parts of the world where social conditions are poor and

health care less available bronchiectasis remains a much more common cause of morbidity

and mortality.

What causes bronchiectasis?

There are numerous causes for bronchiectasis. However, in approximately 50% of cases, an

underlying cause is not found.

The following conditions can cause chronic inflammation resulting from an abnormality of

anatomy, immunity or function:

repeated lung infections e.g. pneumonia, whooping cough, measles, tuberculosis,

adenovirus, influenza virus

primary or secondary immune deficiency e.g. immunoglobulin G subclass deficiency,

hypogammaglobulinaemia, lung and bone marrow transplantation, malignancy,

HIV/AIDS, Human T-Lymphotropic Virus 1 (HTLV1)

asthma and fungal allergy (Allergic bronchopulmonary aspergillosis or ABPA)

mucociliary dysfunction e.g. cystic fibrosis, primary ciliary dyskinesia, Young’s

syndrome, Kartagener’s syndrome

recurrent small volume aspiration e.g. gastro-oesophageal reflux, poor

dentition/recurrent oral infection

bronchial obstruction eg inhalation of foreign objects such as peanuts, tumour,

airway compression, lymph node

systemic inflammatory diseases e.g. rheumatoid arthritis, Sjögren’s syndrome,

inflammatory bowel disease, sarcoidosis

structural lung disease e.g. COPD, asthma, bronchiolitis, interstitial lung disease

Pulmonary fibrosis and pneumoconiosis (eg, silicosis)

It is ideal to identify the cause of bronchiectasis where possible, as disease management

strategies may be appropriate. These strategies may be associated with reducing the

progression of bronchiectasis.

What are the symptoms of bronchiectasis?

The most common symptoms are:

Chronic cough

Sputum of various quantities

But some or all of the following symptoms may be present:

Recurring chest infections (exacerbations)

Haemoptysis

Chest pain

Shortness of breath/ wheeze

Lethargy and exercise limitation

Chronic sinus inflammation

Gastro-oesophageal reflux

Sputum

The normal lung produces approximately 50 millilitres of mucous per day to assist with the

functioning of the muco-ciliary escalator.

Mucous is called sputum when an excess amount is produced within the airways and needs

to be expectorated. The quantity, colour and texture are variable and can be an indicator of

an exacerbation.

To assist with the monitoring of the condition Murray et al developed a sputum colour

chart.

Murray et al. Sputum colour: a useful clinical tool in non-cystic fibrosis bronchiectasis. ERJ 2009;vol34:no2,361-364

This chart does not include the following sputum colours:

• Red due to fresh blood

• Brown due to old blood

• Grey/black from nicotine and pollution

Exacerbations can be associated with inflammation and an accumulation of neutrophils in

the sputum. During bacterial exacerbations new, or an increased number, of bacteria are

found in secretions and this is associated with the production of a key neutrophil

chemoattractant (LTB4), necessary to drive neutrophil influx. The release of LTB4 is very

dependent upon the bacterial load (which probably explains why patients can be

“colonised” by bacteria but remain well). As bacterial numbers rise the neutrophils in the

lung also rise, changing the colour of sputum.

Purulent sputum reflects neutrophil influx into the secretions. For this reason, the

purulence of sputum can be used as a guide to the presence of infection. It not only reflects

the likelihood of identifying bacteria but also the bacterial load, the inflammation and

damaging potential of the secretions.

Common microbial isolates from patients with bronchiectasis are:

Haemophilus influenza

Pseudomonas aeruginosa

Strepcoccus pneumoniae

Staphylococcus aureus

Aspergillus fumigatus

The presence of pseudomonas aeruginosa is associated with higher volumes of sputum,

more advanced disease on HRCT and a poorer quality of life.

Adult patients which the following symptoms should be investigated for bronchiectasis:

Chronic productive cough (particularly if there is no history of smoking)

Unexplained haemoptysis

Recurrent lower respiratory tract infections (particularly with slow recovery)

How is bronchiectasis diagnosed?

Comprehensive medical history taken by GP or respiratory physician including:

History of childhood infection or childhood respiratory symptoms

Family history of bronchiectasis, especially cystic fibrosis

Smoking history

Presence of symptoms to suggest a systemic inflammatory disorder (joint problems,

skin rash, muscle pain)

Duration and severity of symptoms

Frequency of infective exacerbations

Clinical examination:

Peripheral examination for signs of chronic lung disease e.g nail changes (clubbing)

occur in some forms of bronchiectasis

Cough quality, strength and sputum production

Signs to suggest a systemic inflammatory disorder (joints, skin, muscles, eyes)

Listening to the chest. Bronchiectasis is characterised by focal or generalised noises

(crepitations, wheeze, ‘squeaks’) heard with the stethoscope

HRCT

a high resolution CT scan establishes the diagnosis of bronchiectasis

a computerised tomography scan producing cross-section slice images

one scan has effective radiation dose equivalent to 400 chest x-rays

generally undertaken when patient is clinically stable

findings – bronchial wall dilation (internal lumen diameter greater than the diameter

of its adjacent pulmonary artery), failure of the bronchi to taper and visualisation of

bronchi in the outer 1-2cm of the lung fields

Chest x-ray

A baseline chest x-ray should be done for all patients

Repeat x-rays are only required if clinically indicated

Investigations for secondary causes

Spirometry (FEV1, FVC, PEF)

for the measurement of severity of disease

Presence of bronchodilator response (reversibility)

Spirometry should be repeated at least annually

Sputum sample (microbiology and culture)

identify the presence of bacteria or organisms in the sputum

include mycobacterial culture

persistent Staphylococcus aureus may indicate ABPA or CF

Surveillance of sputum microbiology helps guide antibiotic therapy

Pathology

Immunodeficiency screening – IgG. IgA, IgM and IgG levels (derived from a venous

blood sample)

Connective tissue and vasculitis screening – rheumatoid factor, antinuclear

antibodies, antineutrophil cytoplasmic antibodies

Identifying ABPA – Aspergillus in sputum, total IgE, Aspergillus RAST, Aspergillus precipitins (IgG)

Vaccine responses

Immune deficiency may be identified by an impaired vaccine response

Bronchoscopy

Indicated when – response to treatment is poor, HRCT indicative of mycobacterial infection or disease is localised (to exclude obstruction)

Exhaled nasal nitric oxide

Indicated if considering primary ciliary dyskinesia Ciliary tests should be considered in adults with a history of chronic upper

respiratory tract infections or otitis media

Sweat test

To exclude cystic fibrosis

What are the treatment options and goals?

Treatment for bronchiectasis aims to:

Decrease frequency and severity of exacerbations

Decrease symptoms (such as cough and fatigue)

Improve quality of life

Improve exercise tolerance

Maintain or improve lung function

Prolong survival

Treatment options include:

Antibiotics:

either oral, intravenous or nebulised

to attempt eradication of airway isolates

to treat exacerbations

as a long-term maintenance for suppression of chronic colinisation

Airway clearance program:

A daily routine, prescribed by a physiotherapist trained in airway clearance

techniques, to help move sputum out of the lungs, to decrease the risk of infection.

It may include:

: breathing exercises (ACBT and autogenic drainage)

: positive expiratory pressure devices (e.g.Flutter, Pari PEP)

: inhalation of saline via a nebuliser

: positioning (GAD, modified GAD)

see physiotherapy section for more information

Exercise program:

A prescribed exercise program is important to enhance airways clearance and for

general well-being. It should include moderate to high intensity aerobic exercises

and strength training exercises.

see physiotherapy section for more information

Bronchodilators (such as Ventolin, Asmol, Bricanyl, Symbicort)

prescribed, when appropriate, to dilate the airways

bronchodilators can also improve the cilial beat, which may assist with airways

clearance

see medication section for the correct use of these devices

Surgery

may be considered in patients with localised disease that have not responded to

treatment

Removing an obstructing tumour or foreign body

bronchial artery embolization is indicated with massive haemoptysis

in severe cases, lung transplantation may be considered

The treatment of co-morbidities, such as sinusitis and gastro-oesophageal reflux, is covered

in the relevant sections.

Recognising an exacerbation

Prompt and appropriate treatment for exacerbations is required but management depends

on recognising the nature of the episodes.

The diagnosis of a bacterial infection is made when a combination of symptoms exist.

The presence of three or more of the following symptoms in one day (in particular related to

sputum and cough) for at least two consecutive days is a guideline for patients for the

diagnosis of an exacerbation:

increased quantity of sputum

change in sputum colour

increased cough

increased lethargy

increased dyspnoea

increased sinus discharge

new or increased haemoptysis

fever

It is desirable for patients to have an action plan, including a prescription for an appropriate

antibiotic, to commence when the above criteria for an exacerbation are met.

Living with bronchiectasis

Bronchiectasis is a chronic lung condition which is irreversible. It is therefore important for

patients to be educated in ways to improve and/or maintain their quality of life.

This can be achieved by:

adherence to a prescribed daily airways clearance routine

an action plan, including an antibiotic script at home which can be implemented with

symptoms of an exacerbation

adherence to prescribed medications

smoking cessation

maintenance of regular influenza and pneumonia vaccinations*

consuming a well-balanced diet

consumption of adequate fluids (unless on fluid restrictions)

exercise, singing, dancing and laughter all help to clear mucus

regular exercise or physical activity, which may include attendance at a pulmonary

rehabilitation program if necessary

regular reviews – doctors’ visits, spirometry and physiotherapy

*The Cochrane review on influenza vaccination for patients with COPD described that

"inactivated influenza vaccination has a clinically important and significant effect on

influenza-related exacerbations, and probably an effect on the total of exacerbations in

COPD patients" (Poole 2006).

Given the wide overlap between COPD and bronchiectasis, where up to 50% of patients with

COPD have coexistent bronchiectasis (Patel 2004), it is arguably justified that until new

evidence to the contrary exist, patients with bronchiectasis should be routinely vaccinated.

However influenza vaccinations are not without risks and adverse events although mostly

minor, may be serious (Wong 2005). Thus, in the absence of good evidence for the benefits

of annual routine influenza vaccination, individual preferences and risk factors for increased

adverse events should be considered.

Hydration and humidification

What is the prognosis?

To improve prognosis, it is important that patients are educated in the disease and have an

understanding of the preventative measures described above.

Most people with bronchiectasis have a good outlook. A regular airway clearance routine

and an early response to exacerbations with antibiotics is generally a pathway to

maintaining good health. Lung function and quality of life are more likely to decline in those

who don’t look after themselves. In many cases, mortality can be reduced by medical care,

vaccination and improved nutrition.

The outlook, where bronchiectasis is secondary to another condition, may have a worse

prognosis.

Factors associated with poorer prognosis include:

tobacco smoking

gram negative organisms (Escherichia coli and Pseudomonas aeruginosa)

aspergillus in sputum

poor FEV1 and FVC

compromised immunity

Two tools are currently available for the assessment of morbidity and mortality in patients with non-CF bronchiectasis.

1. FACED score

This assessment of severity tool uses the following criteria:

FEV1 Age Chronic colonisation Extension Dyspnoea

2. Bronchiectasis Severity Index

A strong predictor of morbidity and mortality is the Bronchiectasis Severity Index (www.bronchiectasisseverity.com) which predicts one and four year morbidity and mortality (Chalmers et al 2014).

This assessment of severity tool uses the following criteria:

BMI #

%FEV1 Predicted

Previous Hospital Admission

Has the patient been hospitalised with a severe exacerbation in the past 2 years?

Number of exacerbations in previous year

MRC Breathlessness Score **

Pseudomonas Colonisation (chronic colonisation is defined by the isolation of

pseudomonas aeriginosa in sputum culture on 2 or more occasions, at least 3

months apart in a 1 year period)

Colonisation with other organisms (chronic colonisation is defined by the isolation of

potentially pathogenic bacteria in sputum culture on 2 or more occasions, at least 3

months apart in a 1 year period)

Radiological severity

# Body Mass Index (BMI) = weight (kg) ÷ height2 (m)

Normal BMI values range from 20 to 25.

BMI can provide valuable information regarding the patient’s nutritional status – a low BMI

is not desirable in chronic respiratory disease.

Referral to a dietician may be required if:

BMI < 20 = underweight. BMI > 30 = obese.

**MRC Breathlessness Score

1 Not troubled by breathlessness except on strenuous exercise

2 Short of breath when hurrying or walking up a slight hill

3 Walks slower than contemporaries on level ground because of breathlessness, or has to stop for breath when walking at own pace

4 Stops due to breathlessness after walking 100m

5 House bound due to breathlessness, or breathless on dressing or undressing

Bronchiectasis Severity Score (calculated from results of the above criteria)

0- 4 Mild Bronchiectasis1 year outcomes: 0 - 2.8 % mortality rate, 0 - 3.4 % hospitalisation rate4 year outcomes: 0 - 5.3 % mortality rate, 0 - 9.2 % hospitalisation rate

5 – 8 Moderate Bronchiectasis1 year outcomes: 0.8 - 4.8 % mortality rate, 1.0 - 7.2 % hospitalisation rate4 year outcomes: 4 % - 11.3 % mortality rate, 9.9 - 19.4 % hospitalisation rate

9 + Severe Bronchiectasis1 year outcomes: 7.6 % - 10.5 % mortality rate, 16.7 - 52.6 % hospitalisation rate4 year outcomes: 9.9 - 29.2 % mortality, 41.2 - 80.4 % hospitalisation rate