Assessing the clinical or pharmaco‐economical benefit of target controlled desflurane delivery in surgical patients using the Zeus® anaesthesia machine

Summary The Zeus® anaesthesia machine includes an auto‐control mode which allows targeting of end‐tidal volatile and inspired oxygen concentrations. We assessed the clinical benefits and economic impact of this target‐controlled anaesthesia compared with conventional manually controlled anaesthesia. Eighty patients were randomly assigned to receive desflurane either with a fresh gas flow set by the anaesthetist or in auto‐control mode. Drug delivery was adjusted to maintain bispectral index between 40–60 units and systolic arterial pressure under 15 mmHg above its pre‐induction value (upper limit) and over 90 mmHg (lower limit). Blood pressure was maintained in the desired range for 89% and 91% of the maintenance period for auto‐control and manual control respectively (p = 0.49). Bispectral index was in the desired range for 82% and 79% of the maintenance period, for auto‐control and manual control respectively (p = 0.46). Oxygen consumption was more than halved by the use of auto‐control mode, and mean (SD) desflurane consumption during surgery was 0.07 (0.04) vs 0.2 (0.07) ml.min−1 in auto‐control and manual control respectively (p