Updated: 8/20/2020

Chronic Bronchitis

0%
Topic
Review Topic
0
0
N/A
N/A
Questions
8
0
0
0%
0%
Evidence
6
0
0
0%
0%
Videos / Pods
2
Topic
Introduction
  • chronbronDefined as expectoration for > 3 months for > 2 consecutive years
  • Pathophysiology
    • overproduction of mucus due to inflammation
    • central and peripheral airways involved
    • results in hyperplasia of bronchiolar mucus glands and fibrosis of terminal bronchioles
    • ciliary dysfunction
  • Causes
    • smoking
      • chronic irritation promotes hyperplasia of mucus glands and increases mucus production
      • toxicity of smoke destroys ciliated epithelium and replaces with squamous cells which ultimately reduces mucus clearance 
    • cystic fibrosis
      • loss of CFTR function results in increased viscosity of mucus and decreased mucus clearance
Presentation
  • Symptoms
    • dyspnea
    • productive cough
  • Physical exam 
    • wheezing and crackles on auscultation
    • prolonged expiration
    • classic pursed lip breathing
    • "blue bloater" (end-stage)
      • chronic alveolar hypoxia leads to pulmonary hypertension
        • edematous due to right heart failure (end-stage)
      • cyanosis of skin
Evaluation
  • Labs
    • ABG during exacerbation shows hypoxemia and may show acute respiratory acidosis
      • hypoxemia can stimulate increased erythropoetin production by the kidneys 
        • can see polycythemia with prolonged hypoxemia
    • chronic respiratory acidosis 
  • Chest radiograph 
    • cardiomegaly (horizontally oriented)
    • increased bronchial markings (due to mucus)
  • Clinical diagnosis confirmed by lung biopsy (rarely indicated)
    • ↑ Reid index  
      • gland layer > 50% of total diameter of bronchial wall
        • bronchial wall measured from the surface epithelium to the beginning (but not including) the cartilaginous rings
    • patch squamous metaplasia
    • neutrophil infiltration
  • Pulmonary function tests
    • hallmark is obstruction 
    • ↓ FEV / FVC  
      • similar to emphysema
    • ↑ TLC (less than emphysema)
Treatment
  • Conservative
    • smoking cessation
    • home oxygen
  • Pharmacological
    • bronchodilators and inhaled steroids
      • for long-term maintenance
    • systemic steroids and antibiotics
      • for acute exacerbations
    • roflumilast
      • for severe disease
Complications
  • Pulmonary hypertension 
    • chronic alveolar hypoxia results in pulmonary vasoconstriction
      • right side ventricular hypertrophy and failure (cor pulmonale)
      • distended neck veins
      • hepatomegaly

Please rate topic.

Average 4.5 of 15 Ratings

Questions (8)
Evidence (6)
VIDEOS & PODCASTS (3)
EXPERT COMMENTS (6)
Private Note