Bronchietasis

• defined as a pathological diagnosis typically confirmed by radiology.
• Defined as irreversible abnormal dilatation of the bronchial tree.
• It has a variety of underlying causes, with a common etiology of chronic inflammation.
• due to injury to the airways, which is typically associated with chronic and recurrent inflammation because of an abnormality of airway anatomy, immunity or function

 

Aetiologies 

• Idiopathic (Most Common)
• Impaired Host Defenses
  • Cystic Fibrosis (Most Common Cause In Children)
  • Primary Ciliary Dyskinesia, (Kartagener Syndrome, Young Syndrome)
  • Primary Immunodeficiency Disorder (Common Variable Immunodeficiency, Hypogammaglobulinaemia, Chronic Granulomatous Disease
  • HIV/AIDS
• Post-infective (Most Common Known Non-CF Cause In Adults)
  • Bacterial Pneumonia And Bronchitis, eg: S. Aureus, H. Influenzae, B. Pertussis
  • Mycobacterial Infection, eg: Tuberculosis, Mycobacterium Avium-Intracellulare Complex
• Allergic And Autoimmune
  • Allergic Bronchopulmonary Aspergillosis
  • Connective Tissue Disease, eg: Rheumatoid Arthritis 6, Sjögren Syndrome, Systemic Lupus Erythematosus
  • Inflammatory Bowel Disease
• Obstruction
  • Severe Obstructive Lung Disease: Asthma Or Chronic Obstructive Pulmonary Disease
    • 50% of patients with severe COPD will have co-existent bronchiectasis.
    • 15% had a co-existent diagnosis of asthma or COPD
    • is currently usually diagnosed by a chest high-resolution computed tomography (c-HRCT)
  • Neoplasm, eg:  Bronchial Carcinoid, Bronchogenic Carcinoma
  • Inhaled Foreign Bodies
• Congenital
  • Bronchial Tree Malformations, eg:  Mounier-Kuhn Syndrome, Williams-Campbell Syndrome, Pulmonary Sequestration, Bronchial Atresia
  • Alpha-1-Antitrypsin Deficiency
• Others
  • Chronic Aspiration
  • Traction Bronchiectasis Due To Diffuse Lung Disease, E.G. Pulmonary Fibrosis
  • Radiation-Induced Lung Disease
  • Post-Transplantation

 

Paediatric Causes:

• Idiopathic
• Cystic Fibrosis (CF)
  • most common In high-income countries
• • None-CF Conditions
    • primary immune deficiencies (PID)
    • chronic/recurrent aspiration
    • postinfectious entities
    • primary ciliary dyskinesia (PCD)
    • airways malformations

 

Suppurative lung disorders 

(https://www.pediatr-neonatol.com/article/S1875-9572(19)30522-4/fulltext)

• Protracted bacterial bronchitis (PBB)
  • isolated persistent wet cough
  • normal chest imaging (except for occasional peribronchial thickening)
  • resolving after 2–4 weeks of oral antibiotics

 

• Bronchiectasis
  • Presence of persistent or recurrent (>3) episodes of  chronic (>4 weeks) productive cough
  • sometimes with coarse crackles
  • digital clubbing
  • low-income populations have a higher incidence of pediatric bronchiectasis, generally of infectious origin, with early severe manifestations particularly amongst Australian, Pacific Islands and Alaskan native people

 

• Chronic suppurative lung disease (CSLD)
  • In between PBB and bronchiectasis, there is CSLD
  • defines patients with clinical symptoms of bronchiectasis without its radiographic features

 

Mnemonic: CAPT Kangaroo has Mounier-Kuhn

• C: cystic fibrosis or congenital cystic bronchiectasis (Williams-Campbell syndrome)
• A: allergic bronchopulmonary aspergillosis (ABPA)
• P: post-infectious (most common)
• T: tuberculosis (granulomatous disease)
• K: Kartagener syndrome
• M: Mounier-Kuhn syndrome

 

When to suspect bronchiectasis:

• immune deficiency.
• men with primary infertility, particularly when related to azospermia or immotile sperm.
  • milder form of CF
  • Young syndrome or primary ciliary dyskinesia/immotile cilia syndrome
• Patient presenting with chronic respiratory symptoms, cough and sputum production.
  • There is no absolutely accurate way to differentiate between chronic bronchitis, COPD and asthma and bronchiectasis (and indeed as noted all these conditions can co-exist with bronchiectasis)

 

Features that may suggest bronchiectasis in a patient presenting with chronic respiratory symptoms

1. Diagnosis of asthma that is unresponsive to usual management
2. Digital clubbing (this is rare in COPD and asthma)
3. Lack of a significant smoking history
   1. less than an average of 20 cigarettes per day for 10 years) in a person with suspected COPD
4. History of recurrent and/or severe pneumonia including tuberculosis
5. Presence of ‘unusual organisms’ in sputum
   1. (eg. Aspergillus, atypical/nontuberculous mycobacteria, Pseudomonas aeruginosa, Escherichia coli, Klebsiella pneumoniae)
6. Childhood associated with significant environmental and social disadvantage*

 

Diagnosis and assessment

• High-resolution CT is the most accurate modality for diagnosis.
• Plain chest X-ray
  • may demonstrate large airway dilatation
  • not sensitive
  • a normal chest X-ray does not exclude bronchiectasis
  • does not provide an accurate measure of the extent of disease or any associated interstitial damage
  • “tram-track sign,” a dilated airway with thickened walls that are parallel to one another (similar to a tram track)

Chest high-resolution CT scan

• allows an assessment of a number of features of airway anatomy including diameter, wall thickness and the presence or absence of normal tapering.
• HRCT be performed when a patient is clinically stable and not in the setting of an acute exacerbation to avoid temporary airway dilatation that may resolve on subsequent studies
• Re: radiation
  • HRCT has an effective radiation dose of up to 8 mSv
    • equivalent of 400 plain chest X-rays
    • 3.6 years of background radiation
  • This is of particular importance for children and younger adults where the effective radiation dose and the lifetime implications associated with cancer induction are higher.
  • Before ordering a c-HRCT in children and younger adults, specialist input is encouraged to ensure the potential risk of the radiation exposure is balanced by any possible benefit.

 

Spirometry

• spirometry findings can vary and even be normal in the early stages of disease.
• useful in assessing severity of disease, monitoring progression and predicting prognosis (particularly in adults) it cannot be used to exclude or confirm a diagnosis of bronchiectasis

Nnot always associated with evidence of airflow obstruction

• restrictive (reduction in both FEV1 and FVC with normal or elevated FEV1/FVC ratio) or mixed obstructive/restrictive pattern may often seen.
• Spirometry based stratification of bronchiectasis severity based on the COPDX Plan:

Severity     % predicted FEV1

Mild                    60–80%

Moderate          40–59%

Severe               <40%

 

Investigating for secondary causes

• Full blood count
• Immunoglobulin classes IgG, IgA, IgM, and IgG subclasses
• Sputum culture including mycobacterial culture
  • serological tests for Aspergillus and total IgE level in adults, especially if there is a history of wheeze/asthma
  • Test for primary ciliary dyskinesia in children
• A sweat test: Test for cystic fibrosis transmembrane conductance regulator gene mutations
• Bronchoscopy for foreign body or airway abnormality and to obtain specimens for culture of respiratory pathogens, including mycobacteria
• Barium swallow
• Additional immunological tests – total IgE level in children, neutrophil function tests and lymphocyte subsets, and antibody responses to protein and polysaccharide antigens
• Test for primary ciliary dyskinesia in adults
• HIV and HTLV153 serology

 

Management of bronchiectasis in primary care

1. Aim:
   1. monitoring of severity
   2. reducing progression and complications
   3. early treatment of acute exacerbations
   4. minimising disability

 

1. Ongoing management may include:
   1. management of acute exacerbations
   2. pneumococcal and influenza vaccination
   3. treatment of nontuberculous mycobacteria
   4. long term oral and inhaled antibiotics
   5. physiotherapy/exercise training/pulmonary rehabilitation
   6. palliative care
   7. surgery and transplantation.

MDT

• respiratory physician
• Physiotherapist
• palliative care and mental health team
• respiratory nurse.

 

The role of antibiotics

• While bacteria and fungi are often found in the sputum of people with bronchiectasis, their role in disease development, acute exacerbations and progression is variable
• In some cases they may be contributors to airway inflammation, damage and the progression of bronchiectasis (the ‘vicious cycle’ hypothesis)
• However, such organisms may also be commensals, colonising damaged airways but not contributing to acute exacerbations or progressive airway damage.
• Decisions regarding the use of antimicrobials must therefore be based on an individual patient’s response in addition to the results of airway microbiology.

 

Acute exacerbations

acute exacerbation can be defined as two or more of:

• increasing cough
• shortness of breath
• increasing volume/purulence of sputum
• An unexplained significant (>10%) reduction in FEV1 or FVC over days or weeks
• a patient who is not unwell or at risk of sudden deterioration
• The choice of antibiotic should be based on the most recent sputum culture.
  • If this result is negative or not available, commencing treatment with
    • amoxicillin-clavulanate or doxycycline
• The course of therapy should be prolonged (at least 10 days).
• Early follow up (within 4 days) and regular review is required to ensure response and to consider inpatient management early if there is deterioration.
• While the rate of response varies, most patients would be expected to begin to improve within 7 days, although it can take up to 4 weeks to return to a baseline state.

 

Features of an acute exacerbation that need inpatient management

1. Fever >38°C
2. Hypotension (systolic BP <90 mmHg or diastolic BP
3. <60 mmHg)
4. Respiratory rate ≥30/minute
5. Previous need for noninvasive ventilation/ICU
6. Failure to improve after 7 days of oral therapy
7. Hypoxia (new onset of oxygen saturation ≤93% on room air)
8. Confusion
9. Severe disease (FEV1 <40% predicted)
10. Limited home and social supports or difficulty ensuring follow up/review
11. Substantial disability (new onset of being unable to meet self care needs)

 

Long term and other antibiotic dosing strategies

1. patients with frequent exacerbations (three or more per year), a trial of long term antibiotic therapy may be considered
2. regular ‘tune ups’

• regular and intermittent use of intensive antibiotic therapy (typically intravenous) in stable patients.
• commonly used in CF, are supported by little evidence
• not routinely recommended for non-CF bronchiectasis.

1. intensive and prolonged antibiotic treatment with the aim of eradicating Pseudomonas aeruginosa when it is first isolated.
   1. aggressive treatment of P. aeruginosa outside the setting of an acute exacerbation in non-CF bronchiectasis has not been shown to be effective.

 

Inhalational and other therapies

• Inhalational therapy for bronchiectasis can be divided into agents typically used in asthma and COPD, inhalational antibiotics and those used to enhance sputum clearance.
• Given the existence of overlap syndromes it is not surprising that many patients may benefit from management relating to asthma or COPD.
• If there is felt to be co-existant
  • asthma (demonstrated by wheeze and a significant >12% and 200 mL increase in FEV1 with bronchodilators) or
  • COPD (emphysema seen on c-HRCT or significant smoking history)

then a trial of short and long acting beta agonists, anticholinergics and/or inhaled corticosteroids with assessment of response many be warranted.

• Inhalational antibiotics
  • have often been used in bronchiectasis.
  • nebulised gentamicin for 12 months in patients with non-CF bronchiectasis who have chronic sputum bacterial colonisation and at least two acute exacerbations per year has been shown to reduce sputum bacterial colonization

 

Mucolytics 

• bromhexine
• acetyl cysteine
• hyperosmolar agents including hypertonic (6–7%) saline and mannitol.

 

Vaccinations

• Children and adults with bronchiectasis should have enhanced influenza and pneumococcal vaccination schedules
• there is little evidence specifically relating to bronchiectasis and the benefit of pneumococcal and influenza vaccination, the risk of concomitant infection in patients with pre-existing lung disease would support their use in all patients.

 

Physiotherapy and pulmonary rehabilitation

• Physiotherapy to enhance sputum clearance has been a longstanding mainstay of management and there is evidence it improves cough, exercise tolerance and, in children, lung function.
• Given the risk of silent aspiration, head-down sputum clearance techniques are now discouraged.

 

Domiciliary long term oxygen therapy

• In patients with significant disability or a severe reduction in FEV1 (<40% predicted) regular clinical review should include an assessment of suitability for domiciliary oxygen therapy.

 

Prognosis

• approximately 10% of adults with non-CF bronchiectasis will die within 5–8 years of diagnosis with this being directly attributed to their lung disease in over half.
• Factors associated with poorer prognosis include tobacco smoking, Gram negative organisms (especially Escherichia coli and P. aeruginosa) and aspergillus on sputum culture and greater impairment in FEV1 and FVC

 

Management in primary care

• When to refer:
  • all cases should be discussed with specialist
• Vaccinations:
  •  influenza and pneumococcal
  • Atypical mycobacterial disease: macrolide
  • Inhalation and other therapies
• Physiotherapy and pulmonary rehabilitation
• Domiciliary long term oxygen therapy:
  • If FEV1 < 40% predicted then can apply for home oxygen
• Surgery and transplantation:
  • pt aged < 65yo with severe disease and few or no comorbidities should be assessed for suitability.
  • Median survival > 5yrs
• Palliative care:
  • Benzos