Bronchitis (Chronic)

– An obstructive pulmonary disorder characterized by a chronic and recurrent productive cough.

Causes and Incidence

Bronchial irritants (e.g., cigarette smoke) in conjunction with a genetic predisposition are thought to be the chief cause. No firm data are available on the prevalence of this disease, although many pulmonologists report more cases among older adults, and the incidence is higher in heavily polluted areas.

Disease Process

Chronic irritation leads to hypersecretion and hypertrophy of the bronchial mucous glands and an increase in the size and number of goblet cells. These cells invade the terminal bronchioles, damaging cilia, increasing sputum and bronchial congestion, and narrowing the bronchial lumen. As the disease progresses, leukocytes invade the secretions, aggravating the edema and eventually causing tissue necrosis. Granulated squamous epithelium replaces ciliated epithelium and fibroses, leading to tissue scarring, stenosis, and airway obstruction and a severe ventilation-perfusion imbalance.

Symptoms

Chronic bronchitis may be asymptomatic for years. A productive cough and exertional dyspnea are typical presenting signs. The cough becomes increasingly progressive and the sputum production copious; several attacks a year are common. Chest retractions, wheezing, tachypnea, and cyanosis may also be present.

Potential Complications

Cor pulmonale, pulmonary hypertension, right ventricular hypertrophy, and respiratory failure are common complications.

Diagnostic Tests

Clinical evaluation
Any of the above manifestations; history of chronic lung irritation (e.g., smoking, occupational exposure).

Radiology
Increased markings, hyperinflation.

Pulmonary function
Residual volume increased, forced vital capacity and forced expiratory volume decreased; compliance and diffusion normal.

Arterial blood gases
PaO2 decreased, PaCO2 increased.

Sputum
Culture of multiple microorganisms and neutrophils.

Treatments

Surgery – None.

Drugs
Antiinfective drugs for any infection; bronchodilators to reduce dyspnea; corticosteroids to reduce inflammation; flu and pneumonia vaccines for prophylaxis.

General
Removal of irritant; chest physiotherapy to loosen secretions; vaporizer and increased fluids to liquefy secretions; oxygenation for hypoxia; consistent exercise to improve ventilatory and cardiac function.

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