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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