Patient triggered ventilation using a flow triggered system.

The role of patient triggered ventilation (PTV) for the newborn was assessed using a new patient triggered ventilator, the Draeger Bablylog 8000, which incorporates significant improvements in both ventilator performance and the triggering system. Thirty three infants, median gestational age 30 weeks and postnatal age 2.5 days, were entered into the study to compare blood gases obtained during conventional and patient triggered ventilation. Oxygenation did not improve with PTV in the group overall but increased significantly (median change 7%) in infants greater than 28 weeks' gestation. Arterial carbon dioxide tension (PaCO2) decreased during PTV in the majority of infants (median reduction 7%), this was not related to the gestational or postnatal age, but was greatest in infants previously on a low conventional ventilation rate. Blood gases (both PaO2 and PaCO2) deteriorated in infants requiring the highest inspired oxygen concentration. We conclude that patient triggered ventilation is most useful in infants with mild respiratory distress.