Abstract
A saber-sheath trachea is a type of tracheal deformity characterized by coronal narrowing and sagittal widening of the intrathoracic trachea. In this case report, we describe a 76-year-old man with a history of chronic obstructive pulmonary disease (COPD) and repeated episodes of type 2 respiratory failure that responded poorly to inhaled long-acting β2 agonists, long-acting muscarinic antagonists, and corticosteroids. The patient was admitted to our hospital due to a COPD exacerbation. Chest computed tomography (CT) demonstrated marked coronal shortening and narrowing, sagittal widening of the intrathoracic trachea, and bronchiolitis. The tracheal index (TI) was less than two-thirds. Continuous positive airway pressure (CPAP) therapy resolved the type 2 respiratory failure, effectively improving the TI in the dilated coronal trachea. Considering the percentage of low-attenuation areas, airway trapping was observed in CT images. This case report demonstrated that CPAP therapy may improve the narrowing of the central and peripheral airways.