Comparison of two inspiratory: expiratory ratios during high frequency oscillation

Abstract

Routinely maintained longer expiratory than inspiratory times during high frequency oscillation should be discouraged.

High-frequency oscillatory ventilation: What large-animal studies have taught us!

“…A tidal volume of 4.4 ± 1.2 mL/kg was delivered at an I:E of 1:1, delta pressure of 60 cm H 2 O, and rate of 4 Hz. These findings were similar to those observed in other smaller animal models (30)(31)(32). It is interesting to speculate that at the capability of current adult oscillators with delta pressures of 90 cm H 2 O and rates of 3 Hz, tidal volumes of ≥6 mL/kg would be delivered during HFO in this 30-kg lavage injury sheep model.…”

Conventional Mechanical Ventilation Versus High-frequency Oscillatory Ventilation for Congenital Diaphragmatic Hernia

“…Pillow et al showed in a rabbit model, alveolar pressure matched airway opening pressure at I:E ratios of 1:1 but fell when the I:E ratio was reduced to 1:2 indicating a less efficient form of ventilation 20 . Indeed in infants, Dimitriou et al demonstrated that increasing the I:E ratio from 1:2 to 1:1 was associated with a significantly lower PaCO 2 and higher tidal volume 21 . In addition, Alexander and Milner in infants demonstrated using a jacket plethysmograph, there was no gas trapping when the I:E ratio was increased from 1:2 to 1:1 using the Sensor Medics 22 .…”

The effects of inspiratory to expiratory ratio on ventilation and oxygenation during high frequency partial liquid ventilation in a rabbit model of acute lung injury

“…In HFO, I：E ratio did not significantly affect gas exchange or hemodynamics [27,28]. In infants with respiratory distress syndrome, PaCO2 at a I：E ratio of 1：1 was lower than at 1：2 [29].…”