Abstract
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.
Footnotes
- Correspondence: Peter C Rimensberger MD, Neonatal and Pediatric Intensive Care Unit, Department of Pediatrics, University Hospital of Geneva, Rue Willy Donzé 6, 1211 Geneva 14, Switzerland. E-mail: peter.rimensberger{at}hcuge.ch.
The authors have disclosed no conflicts of interest.
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