ANALYSIS OF THE GAS-EXCHANGE SYSTEM DYNAMICS DURING HIGH-FREQUENCY VENTILATION

High-frequency ventilation (HFV) as a form of artificial respiration has attracted interest in recent years as a means of reducing the risk of barotrauma in clinical applications. This paper explores the high-frequency dynamics of the gas exchange system in order to obtain mathematical models that allow optimization studies. A model for the dynamic relation between tracheal flow and CO//2 tension is obtained from experimental data which, in combination with existing models relating tracheal flow to pleural or alveolar pressure, allows optimization of the input flow waveform for a given level of CO//2 elimination rate. The developed relation between CO//2 elimination rate and input was verified by experimentally measured arterial CO// 2 tension.