Excessive Dynamic Airway Collapse-A Case Report

Abstract

The normal airway lumen exhibits transient and partial narrowing during forceful expiration, which is known as ”dynamic airway collapse” (DAC). Excessive DAC (EDAC) results from transient and exaggerated invagination of the membranous posterior tracheobronchial wall, probably due to weakening of the intrinsic elastic tissues, and may impair ventilation and secretion clearance. In this report, we described a female who initially received endotracheal intubation because of severe pneumonia with respiratory failure, during which high cuff pressures and high levels of positive end-expiratory pressure were utilized. Despite having no known history of cigarette smoking, chemical exposure or underlying airway disorder, she subsequently developed frequent expiratory wheeze recalcitrant to inhalational bronchodilators, recurrent low-airway infections, and eventually difficult weaning from mechanical ventilation. Further surveys, including dynamic computed tomographic scan and bronchoscopy, revealed EDAC. The severity of her airway symptoms improved following the use of continuous positive airway pressure. In conclusion, EDAC clinically mimics common obstructive ventilatory disorders. Physicians should remain alert to this disorder, particularly when managing patients with refractory obstructive airway symptoms and difficult weaning.