Tom Bryson Department of Anaesthesia, Liverpool Women's Hospital, Liverpool L8 7SS, UK.
Br J Anaesth. 2013 Apr;110(4):561-6. doi: 10.1093/bja/aes464. Epub 2013 Jan 4.
Automated control of end-tidal inhalation anaesthetic concentration is now possible. The EtControl™ module of an Aisys Carestation Anaesthetic machine digitally adjusts fresh gas flow and plenum vaporizer output to achieve a target end-tidal concentration.
We evaluated EtControl in clinical practice by measuring volatile agent consumption and the need for user input. We compared these values with contemporaneous controls using manual control of fresh gas flow rates.
A total of 321 patients were anaesthetized with EtControl and 168 with manual control of fresh gas flow. The mean [95% confidence interval (CI)] sevoflurane usage for cases of 20-40 min duration was 14 (13-16) ml h(-1) with EtControl and 30 (26-35) ml h(-1) with manual control. For cases of the same duration, the mean (95% CI) desflurane consumption was 27 (21-33) ml h(-1) with EtControl and 45 (29-62) ml h(-1) with manual control. The average number of keypresses per case was 6.5 with EtControl and 13.6 during manual control of fresh gas flow.
Automatic implementation of low-flow anaesthesia using EtControl allows the user to set and maintain a desired end-tidal volatile concentration while using less volatile agent.
现在可以实现呼气末吸入麻醉浓度的自动控制。Aisys Carestation 麻醉机的 EtControl™模块通过数字方式调节新鲜气流和汇流腔蒸发器的输出，以达到目标呼气末浓度。
我们通过测量挥发性药物的消耗和用户输入的需求，在临床实践中评估了 EtControl。我们将这些值与使用手动控制新鲜气流速率的同期对照进行了比较。
共有 321 例患者使用 EtControl 进行麻醉，168 例患者使用手动控制新鲜气流进行麻醉。持续时间为 20-40 分钟的情况下，EtControl 的七氟醚平均（95%置信区间）用量为 14（13-16）ml/h，手动控制的为 30（26-35）ml/h。对于相同持续时间的病例，EtControl 的地氟醚平均（95%置信区间）消耗量为 27（21-33）ml/h，手动控制的为 45（29-62）ml/h。EtControl 每例的平均按键次数为 6.5 次，手动控制新鲜气流时为 13.6 次。
使用 EtControl 自动实施低流量麻醉可以让用户在使用更少挥发性药物的同时设置并维持所需的呼气末挥发性浓度。
