The Pressure Change Inside and Outside of the Trachea during the Respiratory Cycle

概要

論文の詳細を見る
According to classic respiratory physiologoy, tracheal wall is expected to expand during inspiratory phase. However, in clinical cases under respiratory care, inspiratory dyspnea commonly seen in intrathoracic central airway obstruction. The direction of tracheal wall motion is dependent on the pressure difference in and outside of the trachea. Using intubated dogs connected to a mechanical ventilator, we measured intratracheal pressure, peritracheal pressure, and intrathoracic pressure simultaneously. The pressure difference was in the direction of tracheal constriction during the inpiratory phase. During the expiratory phase the pressure difference was in the direction of tracheal expansion. The peritracheal pressure changed in the same magnitude but at shifted levels with the intrathoracic pressure. The intratracheal pressure moved in phase with respiratory flow. These results show pressure relationships that are opposite from the classic physiology. The results from the present study support our clinical report that peak inspiratory flow rate is specifically reduced in intrathoracic central airway obstruction.