Pendelluft effect on gas exchange in high-frequency ventilation

The pendelluft effect on gas transport and exchange in high-frequency ventilation was investigated using a simple computational model in which the pendelluft zone extending over lower airways consists of two branches in asynchronous motion. Calculations were carried out for the case in which the respiration is modulated by the pendelluft mode with amplitude ratio ranging from 0 to 2. The results show that increased regional tidal volume and sloshing of flow markedly improves the gas exchange rate, suggesting that gas exchange comparable to that in ordinary respiration is available in high-frequency ventilation.