2001 OPEN FORUM Abstracts
Comparisonof Bird VIP Gold Ventilator in Conventional Volume Mode to Dräger Babylog 8000+In Volume Guarantee Mode, A Bench Study
E.Collins, RRT; V. Faciane, BSRRT; L Abbruzzese, RRT; Providence Hospital, Anchorage, Alaska
Background:The role of ?Volutrauma? in neonatal lung injury has received increased interest.Two ventilators studied offer different approaches to a volume-targeted breath.VIP Gold offers conventional volume ventilation with a decelerating flow. Babylog8000+ offers pressure limited breaths (TCPL) (PSV) that adjust the pressuretarget to accomplish the selected tidal volume when ?Volume Guarantee? is active.Understanding how these modes function in various clinical settings is vitalto their appropriate use.
Objective: To investigatethe volume delivery of two ventilators to changes in Compliance and Resistance.
Design/ Methods: Usingan IngMar neonatal test lung, both ventilators were set to achieve a desiredexpiratory tidal volume at a compliance of 1.0 ml/cm. Compliance was changedto .5, 1.5 2.0; returned to 1.0 ml/cm and the resulting tidal volume and PIPrecorded for 30 breaths. The process was repeated with a 2.5mm Et tube and a3.5mm Et tube. The Babylog was set in Assist/Control TCPL with Volume Guarantee.The VIP Gold was set in Assist/Control volume mode with decelerating flow. Bothventilators used the same standard disposable heated wire circuit (Allegiance)and Fisher/Paykel 750 heated humidifier. Target tidal volumes were 5, 10, and15 ml.
Results: Both ventilatorsdelivered variable expiratory tidal volumes when compliance was changed. (Seefigure below) The Dräger Babylog 8000+ delivered large fluctuations in expiratorytidal volumes. The VIP Gold had less fluctuation in tidal volume but did notreturn entirely to the set tidal volume. Maximum overshoot: Dräger Babylog 150%;VIP Gold 37%. Changes in resistance did not change the expiratory tidal volumesignificantly for either ventilator.
Conclusion: Changesin compliance resulted in significant changes to actual measured expiratorytidal volume. Such sudden compliance changes could occur in response to surfactanttherapy, when an Et tube is repositioned or a pnuemothorax is recognized. Volumeovershoot with the Dräger Babylog may be attributed to the TCPL mode. A compliancechange could result in a larger volume delivery before the ventilator re-adjuststhe pressure target. VIP Gold volume changes may be attributed to circuit compliancechange. Both ventilators monitor delivered tidal volume at the wye. The resultsof the bench test warrant further study.