Respiratory · Year 1 · from Respiratory
Case 3: Bronchiectasis with Pseudomonas Colonization
Case Presentation
A 45-year-old woman with a history of recurrent pneumonias since childhood presents with chronic productive cough that has worsened over the past month. She produces approximately 50 mL of purulent, foul-smelling sputum daily. She reports intermittent hemoptysis (blood-streaked sputum) and has had three hospitalizations in the past year for respiratory infections requiring IV antibiotics. On examination, she has digital clubbing and scattered crackles over the lower lung fields bilaterally. Vital signs are stable with oxygen saturation 94% on room air.
Sputum culture grows Pseudomonas aeruginosa, the same organism isolated on multiple previous cultures. High-resolution CT chest shows bilateral lower lobe bronchial wall thickening, bronchial dilation (bronchi larger than accompanying pulmonary artery - "signet ring sign"), and lack of bronchial tapering toward the periphery, consistent with bronchiectasis. Pulmonary function tests show FEV1 62% predicted, FVC 78% predicted, FEV1/FVC 0.62, indicating obstructive physiology.
Bronchiectasis is defined as permanent abnormal bronchial dilation from chronic infection and inflammation. A vicious cycle develops: initial airway injury impairs mucociliary clearance, allowing bacterial colonization, which triggers chronic inflammation, causing further airway damage and worsening clearance. Pseudomonas aeruginosa is particularly problematic because it forms biofilms in damaged airways and is difficult to eradicate.
The patient's management includes twice-daily airway clearance therapy with a flutter valve device, nebulized hypertonic saline to improve secretion clearance, chronic suppressive therapy with inhaled tobramycin (alternating months on/off) given her chronic Pseudomonas colonization and frequent exacerbations, and azithromycin three times weekly for its anti-inflammatory and immunomodulatory effects. Her exacerbation frequency decreases from 3-4 per year to 1-2 per year with this regimen.
Key Learning Points
- Bronchiectasis is permanent bronchial dilation from chronic infection/inflammation
- The "vicious cycle" involves impaired clearance, bacterial colonization, inflammation, and further damage
- Pseudomonas aeruginosa colonization is associated with more rapid decline and frequent exacerbations
- CT findings include "signet ring sign" (dilated bronchus larger than artery) and lack of bronchial tapering
- Management includes airway clearance, mucolytics, and often chronic suppressive antibiotics