Removing the Active Exhalation Phase from High Frequency Oscillatory Ventilation

Introduction: High frequency ventilation allows clinicians to treat patients when conventional ventilation is not sufficient. Various mechanical methods are used to achieve high frequency ventilation and these differences can have clinical significance. For example, the difference between passive and active exhalation is very significant when comparing the High Frequency Oscillatory Ventilator (HFOV) with the High Frequency Jet Ventilator (HFJV). The HFOV diaphragm creates an oscillatory pressure wave with both positive and negative pressures and gas flows (active ventilation). HFJV uses a flow interrupter to create high frequency pulse “breaths” without generating any negative pressure …