Abstract
Background and Aims: Nasal high frequency oscillatory ventilation (nHFOV) has been proposed to combine the advantages of oscillatory pressure waveform and of non-invasive interface. We studied the effect of oscillation amplitude and inspiratory time on the pressure transmission and stroke volume delivered through different nasal prongs.
Methods: A bench model of nHFOV was built connecting SM3100A oscillator tubings via two differently sized nasal prongs, to a neonatal lung model carrying mechanical properties of recovering RDS. A standard circuit with no nasal prongs was used as control. Tidal volume (Tv), oscillatory pressure ratio (?Pdist/△Pprox) and ventilation (DCO2) were measured across a range of amplitudes and with inspiratory time (IT) set at 33% and 50%. Measurements were performed with a low-dead space hot wire anemometer coupled with a pressure transducer, specifically validated for neonatal ventilation.
Results: Tv, Pdist/△Pprox and DCO2 were 83%, 40% and 71%, respectively, of those provided with the control circuit. No differences were noticed between small and large prongs. Tv and △Pprox were linked by a quadratic relationship and Tv plateaus for amplitude values > 65 cmH2O. △Pdist/△Pprox shows the same tendency. Same results were obtained with both types of prongs and with increasing IT. On the whole, mean Tv was higher with IT at 50% than at 33% (2.4 mL vs 1.4 mL;p < 0.001).
Conclusions: Changing oscillation amplitude significantly affect ventilation during nHFOV and this effect seems greater than that obtained by varying the frequency. 50% IT always provides an higher Tv delivery and ventilation.
Log in or create a free account to read this content
Gain free access to this article, as well as selected content from this journal and more on nature.com
or
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
De Luca, D., Piastra, M. & Conti, G. Effect of Amplitude and Inspiratory Time in a Bench Model of Non-Invasive High Frequency Oscillatory Ventilation Through Nasal Prongs. Pediatr Res 70 (Suppl 5), 507 (2011). https://doi.org/10.1038/pr.2011.732
Issue date:
DOI: https://doi.org/10.1038/pr.2011.732
