Bronchiectasis and Its Causes

Study Notes

Bronchiectasis Overview

Bronchiectasis involves abnormal widening of the bronchi, leading to chronic airway infections, sputum production, and progressive lung damage.
Tuberculosis is the most common cause of bronchiectasis worldwide.

Etiology and Pathology

Localized bronchiectasis can arise from pus accumulation due to obstruction by factors like tumorous growths or foreign bodies.
Bronchiectatic cavities may be lined with various types of epithelium; chronic inflammation causes scarring and damage to the lung architecture.

Clinical Features

Physical signs can be unilateral or bilateral; absence of secretions results in normal findings.
Large sputum volumes may cause coarse crackles, while blocked airways lead to diminished breath sounds.
Advanced disease may present with scarring and bronchial breathing; rhonchi may be evident.

Investigations

Chest X-ray shows 50% sensitivity; features include ‘ring shadows’, ‘tramlines’, and consolidation around thickened airways.
High-Resolution CT (HRCT) is the investigation of choice with 97% sensitivity, detailing airway dilatation and bronchial wall thickening.
Sputum microbiology includes microscopy and organism cultures, along with immunoglobulin testing and lung function assessments.

Specialized Investigations

CFTR mutation screening for cystic fibrosis.
Assessment of pneumococcal vaccine response; low antibody response indicates immunodeficiency.
Bronchoscopy, nasal nitric oxide testing, and ciliary beat frequency analysis may be conducted for further identification of underlying issues.
Vasculitis screen if associated with connective tissue diseases.

Management Strategies

Physiotherapy to promote bronchial secretions drainage is essential.
Antibiotic therapy typically includes co-amoxiclav, macrolides, and tetracyclines.
Pseudomonas infections may necessitate targeted antibiotics like ciprofloxacin or intravenous anti-pseudomonal β-lactams.

Surgical Treatment

Surgical resection is limited to select cases of bronchiectasis, especially if progressive lung damage is evident.

Cystic Fibrosis (CF) Association

CF, an autosomal recessive genetic disorder, leads to bronchiectasis primarily due to CFTR gene mutations affecting chloride channels.
CF is prevalent among Caucasians, with a carrier rate of 1 in 25 and incidence rates of about 1 in 2500 births.
Dehydration of airway epithelium promotes chronic infections and ciliary dysfunction.

Clinical Features in CF

Patients typically present with normal lungs at birth, but infections can lead to bronchiectasis in childhood, often caused by Staphylococcus aureus.
As CF progresses, colonization by Pseudomonas aeruginosa becomes common, exacerbating lung damage.

Management of CF

Effective management of lung disease in CF mirrors treatment for severe bronchiectasis, emphasizing daily physiotherapy.
Intravenous antibiotics are often required for resistant infections.
Supportive care includes nutritional management, pancreatic enzyme supplementation, and diabetes management.

Novel Therapies in CF

Advancements in CF treatment include small molecules targeting CFTR defects.
Ivacaftor is effective for the G551D mutation, improving lung function and normalizing sweat tests.
Combination therapies may offer additional benefits for patients with other CFTR mutations.

Description

This quiz explores bronchiectasis, a condition characterized by abnormal bronchi dilation and chronic airway infections. Participants will learn about the etiology, pathology, and various causes of bronchiectasis, with a focus on the global prevalence of tuberculosis. Test your knowledge on this important respiratory condition.