Write a short note on bronchiectasis.

Definition

Permanent, abnormal, irreversible DILATATION AND DESTRUCTION of the bronchi, from chronic inflammation destroying the elastic and muscular wall components.

The engine is the "VICIOUS CYCLE" (Cole's hypothesis): an insult impairs mucociliary clearance → bacterial colonisation → chronic neutrophilic inflammation with proteases and elastase → further wall damage and dilatation → worse clearance. Breaking this cycle is the aim of all treatment.

Aetiology

Types: cylindrical (commonest, mildest), varicose, and cystic (saccular) — the most severe, classically post-tuberculous.

Clinical Features

• CHRONIC PRODUCTIVE COUGH with COPIOUS PURULENT SPUTUM — often foul-smelling, characteristically worse on waking and on changing posture
• Sputum separates into three layers on standing
• HAEMOPTYSIS in up to 50%; occasionally massive from hypertrophied bronchial arteries
• Recurrent infections, breathlessness, fatigue and weight loss
• Signs: CLUBBING, COARSE LOW-PITCHED INSPIRATORY CRACKLES that do NOT clear with coughing, wheeze, and in advanced disease cor pulmonale
• Colonising organisms: *H. influenzae* (commonest), *S. pneumoniae*, *Moraxella*, and *PSEUDOMONAS AERUGINOSA*, whose isolation marks more severe disease and worse prognosis

Investigations

• HIGH-RESOLUTION CT — the DIAGNOSTIC investigation (gold standard):
• "SIGNET RING SIGN" — internal bronchial diameter exceeds the accompanying artery
• Lack of normal tapering; visible bronchi within 1 cm of the pleura
• "TRAM-TRACK" thickened parallel walls; mucus plugging and "tree-in-bud" nodularity
• DISTRIBUTION is a clue: upper lobe — post-tuberculous, cystic fibrosis, ABPA; lower lobe — post-infective, aspiration, immunodeficiency; central — ABPA; right middle lobe and lingula — non-tuberculous mycobacteria
• Chest X-ray — insensitive; "tram-lines" and ring shadows; often normal in mild disease
• SPUTUM culture (bacterial, mycobacterial with AFB and CBNAAT, fungal) — repeatedly
• Spirometry — usually obstructive
• Investigate the CAUSE: immunoglobulins and IgG subclasses, *Aspergillus* IgE and total IgE, sweat chloride and CFTR testing, nasal nitric oxide and ciliary studies, alpha-1 antitrypsin, rheumatoid serology, HIV, and bronchoscopy where disease is localised

Management

• 1. AIRWAY CLEARANCE — the cornerstone, and the most under-prescribed treatment.
• Daily physiotherapy with postural drainage, active cycle of breathing, positive expiratory pressure and oscillating devices
• nebulised hypertonic saline. This is what breaks the vicious cycle and must be taught properly and done lifelong.

2. Antibiotics

• Exacerbations: a prolonged course (typically 14 days) guided by previous cultures; cover *Pseudomonas* where isolated
• Long-term macrolide (azithromycin) prophylaxis for ≥ 3 exacerbations per year — exclude non-tuberculous mycobacterial infection first, and monitor QT and hearing
• Nebulised antibiotics for chronic *Pseudomonas*; eradication therapy on first isolation

3. Treat the cause — immunoglobulin replacement, steroids and antifungals in ABPA, antitubercular therapy, removal of a foreign body, treatment of reflux.

4. General: smoking cessation, vaccination, pulmonary rehabilitation, bronchodilators where there is obstruction, nutrition. Inhaled corticosteroids are not routinely indicated unless asthma or COPD coexists.

5. Complications

• MASSIVE HAEMOPTYSIS — resuscitate, position the BLEEDING SIDE DOWN, correct coagulopathy, tranexamic acid, and BRONCHIAL ARTERY EMBOLISATION — the treatment of choice
• Surgical resection for localised disease with severe symptoms or recurrent haemoptysis
• Transplantation in advanced disease