Obstructive pulmonary diseases - Chronic bronchitis

Chronic bronchitis defined clinically by

Defined clinically by a persistent cough with sputum for at least 3 consecutive months in at least 2 consecutive years in the absence of other identifiable causes.

Pathogenesis of chronic bronchitis First part (4)

1. Cigarette smoke or other irritants →

2. Hypertrophy and hyperplasia of submucosal mucous glands in the trachea and bronchi →

3. Mucus hypersecretion in large airways →

4. Coughing/ does not cause airflow obstruction

Pathogenesis of chronic bronchitis Second part (4)

1. Cigarette smoke or other irritants

   1. More goblet cells in the bronchioles = mucus production

   2. Inflammation of bronchioles (macrophages, neutrophils, lymphocytes)

2. Mucus plugs, Edema, fibrosis = AIRFLOW OBSTRUCTION

A patient with chronic bronchitis has an increased risk for pulmonary infections. Why? (3)

Smoking causes:

1. More and thicker mucus

2. Squamous metaplasia

3. Paralyzes cilia

Reid index chronic bronchitis

Increased (> 0.4)

Histology of chronic bronchitis

1. Squamous metaplasia

2. Gland hypertrophy

Consequence of chronic bronchitis (2)

1. Excess mucous production

2. Small airway obstruction

Symptoms of chronic bronchitis (6)(1)

1. Cough with sputum

2. Dyspnea

3. Hypoxemia -> Low O2

4. Hypercapnia -> High CO2

5. Cyanosis

6. Wheezing

Many will also have emphysema