Bronchiectasis refers to the congenital/acquired irreversible airway dilation that involves the bronchi/bronchioles in either a focal or a diffuse manner. It is a pulmonary disease related to chronic infections in the background of inability of respiratory mucosa to clear the infections and impaired ciliary function. It is chronic disease with high morbidity and mortality

1. Bronchiectasis
Denis Katatwire
MMED1-Internal Medicine

2. Outline
i. Introduction
ii. Epidemiology
iii. Aetiology
iv. Pathogenesis
v. Clinical presentation
vi. Diagnosis.
vii. Treatment

3. Introduction
• Bronchiectasis refers to the congenital/acquired irreversible
airway dilation that involves the bronchi/bronchioles in either
a focal or a diffuse manner and that classically has been
categorized as:
i. Cylindrical or Tubular (the most common form)
ii. Varicose, or cystic.

4. Epidemiology
• Varies greatly with the underlying etiology.
• E.g., in CF often develop significant clinical bronchiectasis in
late adolescence or early adulthood, although atypical
presentations of CF in adults in their 30-40’s are also possible.
In contrast, bronchiectasis resulting from MAC infection
classically affects nonsmoking women older than age 50 years.
• Incidence of bronchiectasis increases with age.
• F>M
• More in those with disadvantaged socio-economic status

5. Cont…
• Highly prevalent where TB is prevalent: associated extrinsic
compression of the airway by enlarged granulomatous lymph
node and/or from development of intrinsic obstruction as a
result of erosion of a calcified lymph node through the airway
wall (e.g., broncholithiasis)
• Increased incidence in those with malnutrition

6. Aetiology
• Bronchiectasis can arise from infectious or noninfectious
causes.
• Up to 25–50% of cases the causes can not be identified
(idiopathic)
• Clues to the underlying aetiology are often provided by the
pattern of lung involvement.
i. Focal bronchiectasis = in a localized area of the lung and
can be a consequence of obstruction of the airway—either
extrinsic (e.g., due to compression by adjacent
lymphadenopathy or parenchymal tumor mass) or intrinsic
(e.g., due to an airway tumor or aspirated foreign body, a
scarred/stenotic airway, or bronchial atresia from
congenital underdevelopment of the airway).

7. Cont…
ii. Diffuse bronchiectasis =widespread changes throughout
the lung and often arises from an underlying systemic or
infectious disease process and cigarette/tobacco smoking.
• More of Central airways involvement: allergic
bronchopulmonary aspergillosis (ABPA)which an immune-
mediated process, also cartilage deficiency due
tracheobronchomegaly (Mounier-Kuhn syndrome) and
Williams-Campbell syndrome.

8. Cont…
• More upper lung fields involvement: cystic fibrosis (CF) and
postradiation fibrosis.
• Lower lung fields involvement: chronic recurrent aspiration
(e.g., due to esophageal motility disorders like those in
scleroderma), end-stage fibrotic lung disease (e.g., traction
bronchiectasis from idiopathic pulmonary fibrosis), or
recurrent immunodeficiency-associated infections (e.g.,
hypogammaglobulinemia).
• Predominantly Midlung fields MAC infections dyskinetic/
immotile cilia syndrome = Kartagener’s syndrome.

9. Pathogenesis
• The most widely cited mechanism of infectious bronchiectasis
is the “vicious cycle hypothesis,” in which susceptibility to
infection and poor mucociliary clearance result in microbial
colonization of the bronchial tree.
• The ensuing host response, immune effector cells
(predominantly neutrophils), neutrophilic proteases (elastase),
reactive oxygen intermediates (eg, hydrogen peroxide
[H2O2]), and inflammatory cytokines, creates transmural
inflammation, mucosal edema, cratering, ulceration, and
neovascularization in the airway

10. Cont…
• Some organisms, such as Pseudomonas aeruginosa, exhibit a
particular propensity for colonizing damaged airways and
evading host defense mechanisms.
• Impaired mucociliary clearance can result from inherited
conditions such as CF or dyskinetic cilia syndrome, and it has
been proposed that a single severe infection (e.g., pneumonia
caused by Bordetella pertussis or Mycoplasma pneumoniae)
can result in significant airway damage and poor secretion
clearance.

11. Cont…
• The presence of the microbes incites continued chronic
inflammation, with consequent damage to the airway
wall, continued impairment of secretion and microbial
clearance, and ongoing propagation of the infectious-
inflammatory cycle.
• Moreover, it has been proposed that mediators released
directly from bacteria can interfere with mucociliary clearance

12. Cont…
• Classic studies of the pathology of bronchiectasis from the
1950s demonstrated significant small-airway wall
inflammation and largerairway wall destruction as well as
dilation, with loss of elastin, smooth muscle, and cartilage.
• It has been proposed that inflammatory cells in the small
airways release proteases and other mediators, such as
reactive oxygen species and proinflammatory cytokines, that
damage the larger-airway walls… chronic inflammation
destroy the elastin and cartilage which causes dilation and
weakening of the bronchial walls

13. Cont…
• Furthermore, the ongoing inflammatory process in the smaller
airways results in airflow obstruction.
• It is believed that antiproteases, such as α1 antitrypsin, play
an important role in neutralizing the damaging effects of
neutrophil elastase and in enhancing bacterial killing.
• In addition to emphysema, bronchiectasis has been observed
in patients with α1 antitrypsin deficiency.

14. Cont…
• Proposed mechanisms for noninfectious bronchiectasis
include immune-mediated reactions that damage the
bronchial wall (e.g., those associated with systemic
autoimmune conditions such as Sjögren’s syndrome and
rheumatoid arthritis).
• Traction bronchiectasis refers to dilated airways arising from
parenchymal distortion as a result of lung fibrosis (e.g.,
postradiation fibrosis or idiopathic pulmonary fibrosis).

15. Clinical features
• Most common clinical presentation = persistent productive
cough with ongoing production of thick, mucopurulent
tenacious sputum.
• Hemoptysis
• Dyspnoea
• Wheezing (bases of the lung)
• Chest pain

16. Physical findings
• Cachexia
• Crackles and wheezing on lung auscultation
• ??Clubbing of the digits = sometimes.
• Mild to moderate airflow obstruction is often detected on
pulmonary function tests, overlapping with that seen
at presentation with other conditions, such as COPD. Acute
exacerbations of bronchiectasis are usually characterized by
changes in the nature of sputum

17. Diagnosis
• Suggestive hx of persistent chronic cough and sputum
production
• Physical exam paying attention to the Respiratory system
exam
• Sputum for Gram stain, culture and sensitivity, AFB, GeneXpert
• Bronchoalveolar lavage (BAL) fluid sample
• FBP
• Spirometry: reduced or normal FVC, low FEV1 and low
FEV1/FVC ratio
• Imaging
i. CXR
ii. CT Chest
iii. Bronchoscopy

18. Radiology
• CXR: non specific however presence of “tram tracks” can be
seen
• Chest CT = more specific for bronchiectasis = imaging modality
of choice for confirming the diagnosis. CT findings include
airway
i. Dilation (detected as parallel “tram tracks” or as the
“signet-ring sign”
ii. lack of bronchial tapering
iii. Bronchial wall thickening in dilated airways, inspissated
secretions (e.g., the “tree-in-bud” pattern), or cysts
emanating from the bronchial wall (especially pronounced
in cystic bronchiectasis)

21. Rx
• Rx of infectious bronchiectasis is directed at the control of
active infection and improvements in secretion clearance and
bronchial hygiene so as to decrease the microbial load within
the airways and minimize the risk of repeated infections.
• Antibiotic therapy: targeting the causative or presumptive
pathogen (with H. influenzae and P. aeruginosa isolated
commonly) should be administered in acute exacerbations,
usually for a minimum of 7–10 days.
• MAC strains are the most common NTM pathogens, and the
recommended regimen of a macrolide combined with
rifampin and ethambutol.

23. Bronchial hygiene
• Enhancing secretion clearance in bronchiectasis:
i. Hydration and mucolytic administration: mucolytic
dornase (DNase) is recommended routinely in CF-related
bronchiectasis but not in non-CF bronchiectasis due to lack
of efficacy and potential harm in the non-CF population
ii. Aerosolization of bronchodilators
iii. Hyperosmolar agents (e.g., hypertonic saline)
iv. Chest physiotherapy (e.g., postural drainage, traditional
mechanical chest percussion via hand clapping to the chest,
or use of devices such as an oscillatory positive expiratory
pressure flutter valve or a high-frequency chest wall
oscillation vest).

24. Anti-inflammatory therapy
• Has benefit in bronchiectasis and may improve dyspnea,
decreased need for inhaled β-agonists, and reduced sputum
production.
• Inhaled/Oral glucocorticoids.
• Do not significantly improve lung function or bronchiectasis
exacerbation rates have been observed
• ABPA: prolonged course of treatment with the oral antifungal
agent itraconazole and oral corticosteroids

25. Refractory cases
• Surgery can be considered, with resection of a focal area of
suppuration.
• In advanced cases, lung transplantation if the patient is a
candidate

26. Complications
• Recurrent respiratory infections
• Microbial resistance due to prolonged/repeated antibiotic use
• Toxicity from repeated antibiotics use
• Hemorrhage into bronchial tree resulting into hemoptysis
• Cor pulmonale
• Lung abscess

27. Bronchiectasis exacerbation
• Increased sputum over baseline, thicker sputum, low grade
fever, increased of shortness of breath and pleuritic chest
pain.
• Most of these patients will need to be admitted
• Most commonly due to acute bacterial infections
• Of concern is P. aeruginosa infection which can be lethal

28. Rx of exacerbation
• O2 therapy titrated to 90%
• Routine labs, sputum cultures for Pseudomonas, Mycoplasma
• Broad spectrum antibiotics: if CF, assume Pseudomonas
• Beta agonists bronchodilators
• Chest physiotherapy, Pulmonary toilet (can use
spirometry)/bronchial hygiene
• Expectorants can be given

29. Prognosis
• Outcomes of bronchiectasis vary widely with the underlying
etiology and may also be influenced by the frequency of
exacerbations and (in infectious cases) the specific pathogens
involved.

30. Prevention
• Vaccination of patients with chronic respiratory conditions
(e.g., influenza and pneumococcal vaccines)
• Reversal of an underlying immunodeficient state (e.g., by
administration of gamma globulin for immunoglobulin-
deficient patients)
• Smoking cessation.
• After resolution of an acute infection in patients with
recurrences (e.g., ≥3 episodes per year), the use of
suppressive antibiotics to minimize the microbial load and
reduce the frequency of exacerbations has been proposed,
although there is less consensus with regard to this approach
in non-CF-associated bronchiectasis than there is in patients
with CF-related bronchiectasis.

31. Cont…
• Possible suppressive treatments include
i. Administration of an oral antibiotic (e.g., ciprofloxacin) daily
for 1–2 weeks per month
ii. Use of a rotating schedule of oral antibiotics (to minimize
the risk of development of drug resistance)
iii. Administration of a macrolide antibiotic daily or three times
per week (with mechanisms of possible benefit related
to non-antimicrobial properties, such as anti-inflammatory
effects and reduction of gram-negative bacillary biofilms)

32. Cont…
iv. inhalation of aerosolized antibiotics [e.g., tobramycin
inhalation solution (TOBI)] by select patients on a rotating
schedule (e.g., 30 days on, 30 days off) with the goal of
decreasing the microbial load without encountering
the side effects of systemic drug administration
v. Intermittent administration of IV antibiotics (e.g., “clean-
outs”) for patients with more severe bronchiectasis and/or
resistant pathogens. In addition, ongoing, consistent
attention to bronchial hygiene can promote secretion
clearance and decrease the microbial load in the airways.

33. References
• Harrison's Principles of Internal Medicine; 18Th Edition
• UpToDate