High-Frequency Percussive Ventilation: Pneumotachograph Validation and Tidal Volume Analysis

摘要

INTRODUCTION: High-frequency percussive ventilation (HFPV) is an increasingly used mode of mechanical ventilation, for which there is no proven real-time means of measuring delivered tidal volume (VT). OBJECTIVE: To validate a pneumotachograph for HFPV and then exploit flowsensor data to describe the behavior of both low-frequency and high-frequency breaths. METHODS: Sensor performance was gauged during changes in high-frequency and low- frequency rate and ratio, mean airway pressure, oxygen concentration, heated or heated-humidified gas flow, and endotracheal tube diameter. Glass bottle (adiabatic VT) and test lung (adiabatically derived low-frequency VT) based adiabatic conditions provided both an initial source for analog signal calibration and an accepted standard comparator to flow-sensor measurement of high-frequency and low-frequency (flow-sensor-derived) VT, respectively. RESULTS: Pneumotachography proved accurate and precise over an array of tested settings and conditions when analyzing both high-frequency and low-frequency breaths.