Consumption and Intraoperative Controllability of Desflurane-A Randomized Trial Comparing Manually-Assisted (Perseus® A 500- Dräger) and Automated Control (Aisys® Cs2-GE) of End-Tidal Concentrations

Abstract

Purpose : As compared to conventional manually-assisted administration, the automated-control of end-tidal inhalation anaesthetic concentration (EtControl® Aisys® Cs2 - GE) allows for a reduction of halogenated gas consumption and an improvement of the target end-tidal fraction (Fet) controllability. However, recent real time decision support software may help anaesthesiologists to optimize manually-assisted halogenated agent delivery (VaporView®, Perseus A500® - Drager). The aim of this study was to compare these two delivery methods. Methods: This was a prospective randomized study comparing the consumption and controllability of Desflurane (Des) between the Vaporview® and Etcontrol® modes of administration in daily clinical practice conditions with a hypothesis of non-inferiority. The Vaporview® mode followed a protocol similar to the Etcontrol® mode for the wash in and wash out periods, and followed the Vaporview® curve to adjust the delivered Fraction (Fd) during the maintenance of the end-tidal fraction (Fe) at 0.5 l.min-1 fresh gas flow. Consumptions were measured by micrometric weighing of the vaporizer. Results: 58 patients were randomized. The Desflurane consumption in the Perseus Vaporview` group was 13.71 ml.hr-1 (95% CI: 13.02-14.41) versus 13.27 ml.hr-1 (95% CI: 12.30-14.24) in the reference Aisys Etcontrol® group, satisfying statistical criteria for non-inferiority. There were no significant differences either in time to reach MAC 1, or in the number of Fd/Fe adjustments per hour. Conclusions: Within clinical daily practice conditions, consumption of Desflurane with manually-assisted delivery (Drager Perseus Vaporview®) was not statistically different from automated control delivery (General Electrics Aisys EtControl®), with the same Fe kinetic profiles and ventilator adjustment requirements.