Bronchiectasis

 

• Background

  Pathophysiology

  • Persistent dilation (ectasis) of bronchi due to damage from infection and inflammation.
  • The inflamed, thick-walled, collapsible airways reduce the flow of air and mucous, causing airway obstruction and creating a stagnant pool for recurrent infections to develop.
  • Pathological sub-types are cylindrical (large bronchi and mucus plugging), varicose (alternating dilation and constriction), and cystic (aka saccular). The latter is more severe and linked to CF.

  Causes

  • Infection: frequent and/or severe childhood lung infections, allergic bronchopulmonary aspergillosis, TB.
  • Asthma
  • Immunodeficiency: HIV, immunoglobulin deficiency.
  • Congenital disease: CF, primary ciliary dyskinesia, α-1 antitrypsin deficiency.
  • Gastric aspiration.
  • Obstruction: foreign body, tumour, lymphadenopathy.
  • Autoimmune: RA, Sjogren's, ankylosing spondylitis, SLE, IBD.

  Prevalence

  • 1/400 overall, 1/100 in those aged >70.

• Signs and symptoms

  Can be episodic and/or chronic.

  Symptoms:

  • Cough with voluminous green/yellow sputum, and sometimes specks of blood.
  • Haemoptysis, which in 'dry' bronchiectasis (usually TB) occurs in the absence of sputum.
  • SOB and pleuritic chest pain.
  • Systemic symptoms: fever, weight loss.

  Signs:

  • Coarse, early-inspiratory crackles.
  • Squeaks (high pitch), rhonchi (low pitch), and wheeze.
  • Clubbing

• Investigations

  Bloods:

  • FBC: ↑WBC in infection, ↑RBC if hypoxemic, ↑eosinophils in aspergillosis.
  • ↑CRP in infection.

  Imaging:

  • CXR is often abnormal but non-specific. Shows tram lines (reflecting the absence of normal bronchial tapering), and tubular opacities.
  • High-res CT is required for diagnosis. Shows bronchial dilatation ± wall thickening, mucus-plugged small airways, and fluid-filled cysts.

  Lung tests:

  • Lung function tests: ↓FEV1, ↓FEV1/FVC.
  • Sputum culture: Pseudomonas aeruginosa (25%), H. influenzae, Strep. pneumo, and Staph. aureus are common. Repeated Staph. aureus suggests underlying CF or aspergillosis.
  • Bronchoscopy is only used for suspected foreign body inhalation or obstruction.

  Investigate cause:

  • Serum α-1 antitrypsin.
  • CF sweat test.
  • Immunodeficiency: HIV test, immunoglobulin levels.
  • Rheumatoid factor.
  • Aspergillus IgE and skin prick testing.
  • Sputum pH or swallow study if chronic aspiration suspected. Often used in children.
  • Ciliary function should be tested if no other cause is found and/or there have been chronic problems since childhood. Check exhaled nasal nitric oxide (low in primary ciliary dyskinesia) and follow up with bronchial biopsy with electron microscopy if positive.

  Monitoring:

  • Pulmonary function testing at least annually.
  • Regular sputum MC+S to check changing sensitivities.
  • Repeat imaging not needed unless there is a clinical indication.

• Management

  General measures

  • Smoking cessation.
  • Flu and pneumococcal vaccines.
  • Pulmonary rehab.

  Specific treatment

  Antibiotics

  Therapeutic antibiotics:

  • Longer courses (≥14 days) and sometimes higher doses are needed than in patients without bronchiectasis.
  • MC+S of sputum should always be done.
  • Empirical options: amoxicillin is 1st line, or quinolone if colonized with Pseudomonas.

  Prophylactic antibiotics:

  • Offer to those with frequent exacerbations.
  • Can be nebulized in kids, or in adults colonized with Pseudomonas.
  • Azithromycin is often used, and it also has anti-inflammatory effects.

  Sputum clearance

  • Chest physio for sputum clearance e.g. 30 minutes, 3 times daily.
  • Postural drainage.
  • Nebulised hypertonic saline aids sputum clearance by increasing its hydration. Use bronchodilators before giving as it can cause chest tightness.

  Other medical options

  • Inhaled bronchodilators for those with reversibility (a minority). Options: salbutamol or ipratropium PRN, tiotropium regularly.
  • O2 therapy or non-invasive ventilation for those with respiratory failure.
  • BTS advises against steroids, mucolytics, and leukotriene receptor antagonists.

  Surgery

  • Resection of affected lobe or lung in refractory disease confined to specific area.
  • Lung transplant if FEV1 <30% predicted.

• Complications

  • Respiratory failure.
  • Pneumothorax
  • Lung abscesses and empyema.
  • Cor pulmonale.
  • Massive hemoptysis. Treat with bronchial artery embolisation.