Comparison
of Bird VIP Gold Ventilator in Conventional Volume Mode to Dräger Babylog 8000+
In Volume Guarantee Mode, A Bench Study
E.Collins, RRT; V. Faciane, BS
RRT; 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. Babylog
8000+ offers pressure limited breaths (TCPL) (PSV) that adjust the pressure
target to accomplish the selected tidal volume when ?Volume Guarantee? is active.
Understanding how these modes function in various clinical settings is vital
to their appropriate use.
Objective: To investigate
the volume delivery of two ventilators to changes in Compliance and Resistance.
Design/
Methods: Using
an IngMar neonatal test lung, both ventilators were set to achieve a desired
expiratory tidal volume at a compliance of 1.0 ml/cm. Compliance was changed
to .5, 1.5 2.0; returned to 1.0 ml/cm and the resulting tidal volume and PIP
recorded for 30 breaths. The process was repeated with a 2.5mm Et tube and a
3.5mm 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. Both
ventilators used the same standard disposable heated wire circuit (Allegiance)
and Fisher/Paykel 750 heated humidifier. Target tidal volumes were 5, 10, and
15 ml.
Results: Both ventilators
delivered variable expiratory tidal volumes when compliance was changed. (See
figure below) The Dräger Babylog 8000+ delivered large fluctuations in expiratory
tidal volumes. The VIP Gold had less fluctuation in tidal volume but did not
return entirely to the set tidal volume. Maximum overshoot: Dräger Babylog 150%;
VIP Gold 37%. Changes in resistance did not change the expiratory tidal volume
significantly for either ventilator.
Conclusion: Changes
in compliance resulted in significant changes to actual measured expiratory
tidal volume. Such sudden compliance changes could occur in response to surfactant
therapy, when an Et tube is repositioned or a pnuemothorax is recognized. Volume
overshoot with the Dräger Babylog may be attributed to the TCPL mode. A compliance
change could result in a larger volume delivery before the ventilator re-adjusts
the pressure target. VIP Gold volume changes may be attributed to circuit compliance
change. Both ventilators monitor delivered tidal volume at the wye. The results
of the bench test warrant further study.
OF-01-202
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