Chronic Bronchitis

Definition:
- Chronic sputum production, usually accompanied by chronic cough
- Most days for 3 months of year
- 2/more consecutive years
(when not due to a specific disease e.g. TB)

Pathogenesis:
Chronic irritation
Cigarette smoke & air pollution
 = Death of ciliated cells
 = Reduced mucociliary action

 = Increased mucous production
 = 2ry infection

 = Inflammation & fibrosis

Partially reversible on x Smoking

Classification
1) Simple chronic bronchitis

 - cough, no obstruction
2) Chronic asthmatic bronchitis

 - bronchospasm & wheezing
3) Obstructive chronic bronchitis 

 - COPD

Pathology

Thickened walls, increased size in mucous glands & fibrosis

Increased no of goblet cells = increased mucin production

Squamous metaplasia of respiratory epithelium

Effects
Physical obstruction

• Thickened wall

Submucous gland hyperplasia
Measured in Reid index
Normal = 0.14 - 0.36 (mean = 0.26)
Chronic Bronchitis = 0.41 - 0.79 (mean = 0.59)

• Mucus accumulation

Increased production

 - From increased goblet cells & mucous gland size
Impaired clearance

 - From loss of ciliated epithelium & thicker mucus