A Review of Experimental and Theoretical Studies of High Frequency Ventilation

Abstract

High frequency ventilation (HFV) is a new mode of mechanical ventilation in which the ventilatory rates are higher and the tidal volumes considerably smaller than those observed during spontaneous breathing. Using this technique, investigators from a number of centers have shown that it is possible to maintain eucapnia even when the tidal volumes (VD) are less than the anatomic dead space (VD). These results are clearly in conflict with traditional concepts of gas exchange which are based on the principle that adequate alveolar ventilation is possible only if VT is greater than VD. In an attempt to further our understanding of the mechanisms, by which HFV is effective, we have developed a theoretical model of gas mixing during HFV and we have performed experiments in hardware models, animals and humans to determine the effect of variables thought to be important during HFV. The purpose of this paper is to summarize some of our theoretical and experimental results relating to the mechanisms of gas exchange during HFV.KeywordsTidal VolumeVolume Flow RateOscillatory FlowAirway OpeningHigh Frequency VentilationThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.