Bronchiectasis is a chronic suppurative and inflammatory lung disease of diverse etiology characterized by pathological and irreversible dilatation of the bronchial tree. The impairment of the mucociliary clearance, which results from chronic airway inflammation, may cause long-term colonization or recurrent infection of bacteria, especially Pseudomonas aeruginosa (PA), while bacterial colonization and recurrent infection can aggravate airway inflammation. Sputum retention caused by the impairment of mucociliary clearance can result in mucous plugs, which in turn contribute to airflow obstruction and dyspnea.
Clinically, the major manifestations of bronchiectasis include chronic cough with purulent sputum, dyspnea, and fatigue, which can significantly diminish patients' quality of life. The frequency of exacerbations and decline in lung function may lead to a poor prognosis and a decrease in quality of life.
The purpose of bronchiectasis management is to reduce exacerbations, prevent complications, and improve the quality of life. Long-term instillation of antibiotics and steroids can reduce the concentration of bacteria in the airways, decrease sputum production, attenuate lung function decline, and reduce acute pulmonary exacerbations without nephrotoxicity or ototoxicity. Dexamethasone is one of the most common glucocorticoids that can inhibit the expression levels of inflammatory factors in the airway and reduce the secretion of airway mucus. Topical administration could also reduce the systemic side effects.