Review Question - QID 105823

This patient's clinical presentation is consistent with a diagnosis of chronic bronchitis. Pulmonary function tests in patients with chronic bronchitis would be expected to show decreased FEV1, decreased FEV1/FVC ratio, increased total lung capacity (TLC), and normal diffusing capacity (DLCO).

Chronic bronchitis, along with emphysema, is a common form of COPD. By definition, chronic bronchitis involves the presence of a productive cough for greater than 3 months per year for at least 2 consecutive years. These patients are often termed "blue bloaters" due to their cyanotic appearance secondary to hypoxia. Chronic bronchitis is characterized by excessive mucus production with airway obstruction due to hyperplasia of mucus-producing glands. Goblet cell metaplasia and peribronchial inflammation are also present. In contrast to emphysema, the pulmonary capillary bed is undamaged.

Heath et al. summarize the management of chronic bronchitis in the primary care setting. Inhaled ipratropium and sympathomimetics are first-line treatments. Oral steroids are reserved for patients who do not demonstrate improvement after receiving inhaled agents. Antibiotics, smoking cessation, and supplemental oxygen are other beneficial management options.

Lee et al. report on the results of a systematic review of the role of prophylactic antibiotic therapy in COPD and, more specifically, chronic bronchitis. They find that prophylactic antibiotics significantly reduce the frequency of COPD and chronic bronchitis exacerbations.

Illustration A depicts the differing pathophysiology between chronic bronchitis and emphysema. Illustration B shows a chest radiograph from a chronic bronchitis patient; note the increased bronchovascular markings secondary to chronic inflammation, bilaterally hyperlucent lungs of large volume, flattened hemidiaphragms with widened costophrenic angles, horizontal ribs, and a narrow mediastinum.

Incorrect Answers:
Answer 1: DLCO is normal in chronic bronchitis; a decreased DLCO is more consistent with a diagnosis of emphysema.
Answer 3: Decreased FEV1 and Normal FEV1/FVC is characteristic of a restrictive lung disease, which can manifest with a normal FEV1/FVC ratio due to a similar reduction in both values.
Answer 4: Reduced lung capacity and increased or normal FEV1 and FEV/FVC is more consistent with restrictive lung disease.
Answer 5: Entirely normal lung function would not be expected in such a patient who exhibits profound clinical manifestations of chronic bronchitis over several years.