chronic bronchitis

Introduction

Cough with sputum for 3 or more months/year for 2 or more consecutive years. Patients with chronic bronchitis are the blue bloaters of COPD.

Etiology

• cigarette smoking (most common cause)
• occupational exposure & air pollution contribute to exacerbations
• chronic bronchitis with multiple exacerbations of acute bronchitis in never smokers & in younger patients may be due to bronchiectasis

Epidemiology

onset > 50 years of age

Pathology

• ratio of bronchial mucous glands to bronchial wall thickness (Reid index) is increased
• development of cor pulmonale is common
• nocturnal oxygen desaturation
  • common
  • correlates with an increase in pulmonary artery pressure

Clinical manifestations

• cough productive of sputum
• tend to appear cyanotic
• generally overweight
• infections exacerbate symptoms
• dyspnea is moderate to marked

Diagnostic procedures

• Pulmonary function testing:
  • increased pCO2
  • decreased pO2
  • DLCO normal or slightly decreased
  • FEV1 is decreased & FEV1/FVC decreased in most but not all patients
  • total lung capacity is normal or slightly increased
  • residual volume is normal or slightly increased
• sleep study if sleep apnea is suspected
  • polycythemia or cor pulmonale despite daytime pO2 > 60 mm Hg

Radiology

• chest X-ray shows increased markings

Differential diagnosis

• bronchiectasis (never smokers, younger patients)
• emphysema: FEV1/FVC is low (all patients)
• asthma: reversible airway obstruction
• tracheobronchomalacia:
  • dynamic collapse of the airway during expiration (bronchoscopy)

Management

see COPD

More general terms

• chronic obstructive pulmonary disease (COPD)
• bronchitis

More specific terms

• eosinophilic bronchitis

Additional terms

• features of chronic bronchitis vs pulmonary emphysema
• Reid index