2. ā¢ Bronchiectasis refers to an irreversible airway dilation of lungs.
ā¢ It involves the lung in either a focal or a diffuse manner and that
classically has been categorized as cylindrical or tubular (the most
common form), varicose, or cystic.
3. Etiology
1) Focal bronchiectasis- refers to bronchiectatic changes in a
localized area of the lung.
Causes:-
ā¢ Obstruction of the airway-
i. Extrinsic- compression by adjacent lymphadenopathy or
parenchymal tumor mass.
ii. Intrinsic- due to an airway tumor or aspirated foreign body, a
scarred/stenotic airway, or bronchial atresia from congenital
underdevelopment of the airway
4. 2) Diffuse bronchiectasis- It is characterized by widespread
bronchiectatic changes throughout the lung.
Causes:-
a) Infection- bacterial, nontuberculous mycobacterial
b) Immunodeficiency-hypogammaglobulinemia, HIV infection.
c) Genetic causes-Cystic fibrosis,Ī±1 antitrypsin deficiency.
d) Autoimmune or rheumatologic causes- Rheumatoid arthritis, Sjogrenās
syndrome, inflammatory bowel disease
e) Immune mediated disease- Allergic bronchopulmonary aspergillosis
5. f) Miscellaneous- traction bronchiectasis from postradiation fibrosis
or idiopathic pulmonary fibrosis, recurrent aspiration.
g) Idiopathic
7. Pathogenesis and Pathology
ā¢ Vicious cycle hypothesis
ā¢ Susceptibility to infection and poor mucociliary clearance result in
microbial colonization of the bronchial tree.
ā¢ 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.
8. ā¢ Small-airway wall inflammation and larger airway wall destruction
as well as dilation, with loss of elastin, smooth muscle, and
cartilage.
ā¢ 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.
ā¢ The ongoing inflammatory process in the smaller airways results in
airflow obstruction.
9. ā¢ Mechanisms for noninfectious bronchiectasis include immune-
mediated reactions that damage the bronchial wall.
10. Clinical Manifestations
ā¢ Persistent productive cough.
ā¢ Sputum- thick, tenacious.
ā¢ Physical Examination-
- lung auscultation ļ Crackles and Ronchi.
- Clubbing of the digits.
12. CT- THORAX
ā¢ Chest computed tomography-imaging
modality of choice.
ā¢ CT findings include airway dilation
(detected as parallel ātram tracksā
or as the āsignet-ring signāāa cross-
sectional area of the airway with a
diameter at least 1.5 times that of
the adjacent vessel),
ā¢ Lack of bronchial tapering (including
the presence of tubular structures
within 1 cm from the pleural
surface),
ā¢ Bronchial wall thickening in dilated
airways, inspissated secretions (e.g.,
the ātree-in-budā pattern),
ā¢ Cysts emanating from the bronchial
wall (especially pronounced in cystic
bronchiectasis
14. Treatment
ā¢ Goals of treatment:-
1. Control of active infection.
2. Improvements in secretion clearance and bronchial hygiene so
as to decrease the microbial load within the airways.
3. Minimize the risk of repeated infections.
15. ANTIBIOTIC TREATMENT
ā¢ Antibiotics targeting the causative or presumptive pathogen
should be administered in acute exacerbations, usually for a
minimum of 7ā10 days.
ā¢ For NTM (usually MAC)- Macrolide combined with rifampin and
ethambutol.
16. BRONCHIAL HYGIENE
ā¢ Approaches used to enhance secretion clearance in bronchiectasis
include:-
i. Hydration and mucolytic administration
ii. Aerosolization of bronchodilators
iii. Hyperosmolar agents (e.g., hypertonic saline)
iv. Chest physiotherapy.
18. REFRACTORY CASES
ā¢ Resection of a focal area of suppuration.
ā¢ In advanced cases, lung transplantation can be considered.
19. Complications
ā¢ Recurrent infections can result in injury to superficial mucosal
vessels, with bleeding and, in severe cases, life-threatening
hemoptysis.
20. Prevention
(1) Administration of an oral antibiotic (e.g., ciprofloxacin) daily for 1ā2
weeks per month.
(2) Use of a rotating schedule of oral antibiotics.
(3) Administration of a macrolide antibiotic daily or three times per week.
21. (4) Inhalation of aerosolized antibiotics (e.g., tobramycin inhalation
solution) on a rotating schedule (e.g., 30 days on, 30 days off ),
with the goal of decreasing the microbial load without eliciting the
side effects of systemic drug administration.
(5) Intermittent administration of IV antibiotics for patients with
more severe bronchiectasis and/or resistant pathogens.
22. (6) Bronchial hygiene- promote secretion clearance and decrease
the microbial load in the airways.