Bronchiectasis

Bronchiectasis

Definition
Abnormal dilatation of the bronchi, which may be focal or diffuse

pathogenesis

Recurrent infections
Dilatation of the bronchi
Chronic colonization by pathogenic microorganisms
Accumulation of pus
Impaired drainage of bronchial secretions
Destruction of the bronchial wall
Severe inflammation

Pathology

Dilated bronchi, with destruction of the cartilage, muscle and elastic tissue of their wall, transmural inflammation and pus filled lumen. Chronic inflammation and fibrotic changes in the surrounding lung

Aetiology

Congenital causes Cystic fibrosis Primary ciliary dyskinesia Immunoglobulin deficiency Acquired causes Tuberculosis Severe pneumonia Allergic bronchopulmonary aspergillosis

Aetiology

Primary ciliary dyskinesiaCongenital dysfunction of the ciliaRetention of secretions & recurrent infectionsSperms are immotile leading to infertilityOne half have Kartagener’s syndrome (bronchiectasis, sinusitis, and transposition of the viscera)

Aetiology

Immunoglobulin deficiency Occurs in diseases like; X-linked hypogammagloulinemia, common variable immunodeficiency, and IgA deficiency Recurrent bronchopulmonary infections and bronchiectasis

Aetiology

Tuberculosis Most common cause worldwide Directly destroys bronchi Indirectly through bronchial obstruction by lymph nodes

Aetiology

Severe pneumonia Childhood pneumonia (commonly complicating whooping cough & measles) Suppurative pneumonia in adults (necrotizing and destructive) Recurrent pneumonia (in an obstructed bronchus)

Clinical features

Symptoms Cough: chronic, productive of copious purulent sputum. Haemoptysis: mild, mixed with sputum. Or massive (from dilated bronchial artery). Or alone in dry bronchiectasis. Dyspnoea & wheezing: (in extensive disease), because of bronchial obstruction by thick secretion & bronchial collapse General symptoms: lassitude, anorexia, weight loss, and low grade fever.



Clinical features
Acute exacerbations are characterized by: in cough in sputum amount and purulence in dyspnoeaFeverPleuritic chest pain

Clinical features

Signs: Clubbing of fingers is common Chest examination: a. Crepitation: numerous coarse crepitations on the affected side b. Rhonchi: due to airway obstruction c. Signs of collapse: ( in case of bronchial obstruction)

Clinical features

Complications: Respiratory failure Cor pulmonale and right heart failure Amyloidosis Metastatic abscess (like brain abscess)

Investigations

Imaging: Chest radiograph: the majority of chest XR are abnormal but non-specific. more specific features include: tram-line tracts & ring shadows.

Investigations

Imaging: Severe bronchiectasis appears as large cystic spaces

Investigations

Imaging: CT scan: (esp. high resolution CT) is the imaging modality of choice. It shows thickened and dilated bronchi

Investigations

Bacteriological examination of the sputum: Sputum Gram stain & culture during exacerbation Usual pathogens: Haemphilus influenzae Pseudomonas aeruginosa Streptococcus pneumoniae Klebsiella pneumoniae Moraxella cattarhalis

Investigations

Investigations to define the underlying cause: Sweat ion electrophoresis (cystic fibrosis) Assessment of ciliary function (primary ciliary dyskinesia) Serum immunoglobulin level (immunoglobulin deficiency) Bronchoscopic examination (bronchial obstruction)

Treatment

1. Antibiotic therapy 2. Chest physiotherapy 3. Inhaled bronchodilators and corticosteroids 3. Surgical therapy

Treatment

Antibiotic therapy Antibiotic therapy during acute exacerbation should include drugs that cover the possible underlying microorganisms and guided by sputum culture. Mild cases: oral amoxicillin-clavulinate or a macrolide. More severe cases: flouroquinolons such as levofloxacin or ciprofloxacin are the drugs of choice. Alternatives include third generation cephalosporines like ceftazidime Frequent exacerbations: intermittent regular courses continuous suppressive treatment with oral antibiotics (usually azithromycin through its anti-inflammatory effect).

Treatment

Physiotherapy Postural drainage and chest percussion to keep the airways empty of secretions Reduces the amount of cough and sputum and reduces exacerbation.

Treatment

Inhaled bronchodilators and corticosteroidsInhaled  agonists or anticholenergics enhance airway patency to facilitate drainage and improve breathlessness.Inhaled corticosteroids are used for patients with distressing cough and wheezing


Prevention
Childhood immunization against whooping cough, measles and tuberculosis Adequate treatment of respiratory infections Early treatment of bronchial obstruction

Cystic fibrosis

Definition
Cystic fibrosis (CF) is the most common autosomal recessive disease. It occurs as a result of a mutation in the gene that codes for chloride channel (called cystic fibrosis transmembrane conductance regulator (CFTR)). CFTR controls ion transport across epithelial membrane

Pathology

The genetic defect causes: Increased Na and Cl content in sweat Increase sodium and water resorption from the respiratory epithelium resulting in: thick viscid secretions, chronic bacterial infection and ciliary dysfunction leading to bronchiectasis. Thick biliary and pancreatic secretions obstruct their ducts and result in malabsorption.

Clinical features

Bronchiectasis develops in childhood with progressive lung damage that ultimately ends with respiratory failure. Most affected men are infertile due to failure of development of vas deferens. Fat malabsorption results in steatorrhoea and malnutrition. Diabetes mellitus develops in 25% of cases due to pancreatic islet cell damage.

Investigations

The diagnosis is: Suspected clinically supported by Finding high sweat electrolyte and genetic testing for CFTR mutation. Sputum culture results: Staphylococcus aureus in childhood resistant strains of Pseudomonas aeruginosa and Burkholderia cepacia (chronic colonization)

Treatment

The management of CF lung disease is that of severe bronchiectasis. During exacerbation, antibiotics are given in combinations to cover resistant Gram negative bacilli, particularly Pseudomonas aeruginosa; given intravenously for prolonged periods.


Treatment
Long term treatments which were proved useful in improving symptoms and reducing the frequency of exacerbations include: Prophylactic inhaled antibiotics (like tobramycin) as suppressive therapy for patients with chronic pseudomonas colonization. Nebulized recombinant human DNAas to reduce sputum viscosity. Nebulized normal saline twice daily. Treatment with oral CFTR correctors and potentiaters (lumacaftor/ivacaftor).