RESUMO
In order to study the changes of airflow characteristics in dependent regions of lower respiratory tract in patients with acute respiratory distress syndrome (ARDS), a three-dimensional model of human lower respiratory tract was established based on CT images, and the positions of airway closure in dependent regions were selected. The transient airflow in lower respiratory tract was numerically simulated based on computational fluid dynamics (CFD) technology. The variation trends of airflow velocity, surface pressure and wall shear stress in lower respiratory tract after partial airway closure were obtained. The pathophysiological changes in the development of ARDS were understood, which could guide the strategy of mechanical ventilation and avoid the occurrence of ventilator-associated lung injury.