Obstructive pulmonary disease

Chronic bronchitis

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PubMed search: chronic bronchitis [title] lungs copd

Elliot Weisenberg, M.D.
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Cite this page: Weisenberg E. Chronic bronchitis. website. Accessed October 4th, 2023.
Definition / general
  • Diagnosis: persistent cough with sputum for 3 months in 2 consecutive years without other apparent explanation (eMedicine)
  • Chronic disease of large airways, variable inflammation
Clinical features
  • Simple chronic bronchitis: cough but no physiologic evidence of airway obstruction
  • Chronic asthmatic bronchitis: hyperreactive airways with intermittent bronchospasm and wheezing
  • Obstructive bronchitis: often have associated emphysema, small airway disease
  • Causes: 4× - 10× more common in smokers, chronic irritation and infections may contribute
  • Other causes and contributors are air pollution including passive cigarette smoke, marijuana smoke and occupational dust exposure
  • Tobacco interferes with ciliary action, directly damages airway epithelium and inhibits ability of white blood cells to clear bacteria; infections maintain but do not initiate chronic bronchitis
  • Often diagnosed at time of acute respiratory illness (Prim Care Respir J 2010;19:371)
  • More infections, purulent sputum, hypercapnia, hypoxia than emphysema; clinically called "blue bloaters"
  • May cause secondary pulmonary vascular hypertension, cor pulmonale, congestive heart failure, death due to respiratory acidosis and coma, congestive heart failure and pneumothorax
  • Reid index: ratio of thickness of mucus gland layer to thickness of wall between epithelium and cartilage; normal is 0.4, increased in chronic bronchitis
Gross description
  • Boggy mucosa with excessive mucinous secretions, pus, prominence of bronchial mucosal pits overlying the orifices of bronchial mucous glands
Microscopic (histologic) description
  • Early: hypersecretion of mucus in large airways with hypertrophy of submucosal glands in tracheobronchial tree
  • Later: increase in goblet cells in small airways contributes to excessive mucus production and airway obstruction
  • Increased percentage of bronchial wall is occupied by submucosal mucous glands, as measured by Reid index; this directly correlates with sputum production, variable dysplasia, squamous metaplasia, bronchiolitis obliterans
  • Chronic inflammatory infiltrates range from absent to prominent
Microscopic (histologic) images

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Mucosal glandular hyperplasia

Mucosal glandular hyperplasia

Chronic inflammatory infiltrate

Chronic inflammatory infiltrate

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