TY - JOUR T1 - New Generation Neonatal High Frequency Ventilators: Effect of Oscillatory Frequency and Working Principles on Performance JF - Respiratory Care SP - 363 LP - 370 DO - 10.4187/respcare.03048 VL - 60 IS - 3 AU - Serge Grazioli AU - Oliver Karam AU - Peter C Rimensberger Y1 - 2015/03/01 UR - http://rc.rcjournal.com/content/60/3/363.abstract N2 - BACKGROUND: Several new generation neonatal ventilators that incorporate conventional as well as high frequency ventilation (HFOV) have appeared on the market. Most of them offer the possibility to use HFOV in a volume-targeted mode, despite absence of any preclinical data. With a bench test, we evaluated the performances of 4 new neonatal HFOV devices and compared them to the SensorMedics HFOV device. METHODS: Expiratory tidal volumes (VT) were measured for various ventilator settings and lung characteristics (ie, modifications of compliance and resistance of the system), to mimic several clinical conditions of pre-term and term infants. RESULTS: Increasing the frequency proportionally decreased the VT for all the ventilators, although the magnitude of the decrease was highly variable between ventilators. At 15 Hz and a pressure amplitude of 60 cm H2O, the delivered VT ranged from 3.5 to 5.9 mL between devices while simulating pre-term infant conditions and from 2.6 to 6.3 mL while simulating term infant conditions. Activating the volume-targeted mode in the 3 machines that offer this mode allowed the VT to remain constant over the range of frequencies and with changes of lung mechanical properties, for pre-term infant settings only while targeting a VT of 1 mL. CONCLUSIONS: These new generation neonatal ventilators were able to deliver adequate VT under pre-term infant, but not term infant respiratory system conditions. The clinical relevance of these findings will need to be determined by further studies. ER -