Which of the following is a major complication of chronic bronchitis?
**Core Concept**
Chronic bronchitis is a type of chronic obstructive pulmonary disease (COPD) characterized by persistent inflammation and irritation of the bronchial tubes, leading to excessive mucus production and coughing. This condition is often associated with smoking and long-term exposure to air pollutants.
**Why the Correct Answer is Right**
The major complication of chronic bronchitis is respiratory failure. This occurs due to the progressive destruction of the bronchial walls and airway obstruction, leading to impaired gas exchange and reduced lung function. As the disease progresses, patients may experience worsening shortness of breath, decreased exercise tolerance, and increased risk of respiratory infections. Chronic bronchitis also increases the risk of pulmonary hypertension, which further exacerbates respiratory failure.
**Why Each Wrong Option is Incorrect**
**Option A:** Pneumothorax is not a direct complication of chronic bronchitis, although it may occur in patients with advanced COPD due to lung bullae rupture.
**Option B:** Pulmonary embolism is not a typical complication of chronic bronchitis, although patients with COPD may be at increased risk of thromboembolic events due to chronic hypoxia and immobility.
**Option C:** Asthma is a different pulmonary condition characterized by reversible airflow obstruction, airway hyperresponsiveness, and eosinophilic inflammation. While both conditions involve airway obstruction, they have distinct pathophysiological mechanisms.
**Clinical Pearl / High-Yield Fact**
Chronic bronchitis often presents with a persistent cough productive of thick, yellow or green mucus, which can be a diagnostic clue. Patients may also experience wheezing, chest tightness, and shortness of breath, especially with exertion.
**Correct Answer:** C. Respiratory failure.