J024054 Gas redistribution in respiratory bronchioles during the high frequency oscillatory ventilation

Abstract

High frequency oscillatory ventilation (HFOV) is an artificial respiration technique characterized with a low tidal volume and a high frequency. The present study aims to consider the effects of its ventilation frequency on the gas exchange in respiratory bronchioles. The geometrical model of the respiratory bronchioles was created on basis of Weibel's data. The flow in a dichotomous model was numerically studied with a sinusoidal inflow and flow-compliance-based pressure outlet conditions. The results demonstrated a significant dependency of gas redistribution on the ventilation frequency. Higher frequency of ventilation caused shallower but deeper penetration of an inhaled air from the central part of the airway. The volume of a gas replacement per second, assessed as integration of inwardly penetrated flow, had maximal at the ventilation frequency of 15 Hz. These results suggests the importance of adjustment of ventilation frequency for achieving efficient gas replacement in HFOV.