Dynamic lung inflation during high frequency oscillation in neonates.

The effects of high frequency oscillation (HFO) on dynamic lung inflation were examined in 22 neonates ventilated for respiratory disease. HFO was combined with conventional ventilation and a series of frequencies from 2-25 Hz was tested. Dynamic lung inflation was measured using a jacket plethysmograph which was converted to a measure of alveolar pressure using the compliance of the respiratory system obtained during conventional ventilation. The results showed an increase in dynamic lung inflation with frequency such that volume increased by 0.4 ml for each increase of 10 Hz. Alveolar pressure increased by 1.2 cm H2O for each increase of 10 Hz. Dynamic lung inflation also increased with increased volumes of oscillation.