Fu F, Chen X, Feng Y, Shen Y, Feng Z, Bein B
Department of Anaesthesia, Women's Hospital , School of Medicine, Zhejiang University, Xueshi Road 1, Hangzhou, Zhejiang 310006, China.
Br J Anaesth. 2014 Mar;112(3):506-13. doi: 10.1093/bja/aet383. Epub 2013 Nov 26.
Varying levels of female sex hormones during the menstrual cycle were found to influence the central nervous system. The goal of the present study was to investigate whether the median (50%) effective effect-concentration (EC50) of propofol inducing loss of consciousness (LOC) varies between the luteal and the follicular phases of the menstrual cycle.
Twenty-two patients (follicular phase) and 20 patients (luteal phase) undergoing gynaecological procedures under general anaesthesia were enrolled on the study. Anaesthesia was conducted with a target-controlled infusion (TCI) of propofol. The initial target effect-site propofol concentration (Ceprop) was 3.5 µg ml(-1) and was adjusted stepwise by 0.5 µg ml(-1) at 4 min intervals by an up-down sequential method to reach LOC. Anaesthesia was maintained with a propofol TCI guided by the bispectral index. The correlation between female sex hormones and predicted Ceprop at the time of LOC was analysed and emergence time from anaesthesia was recorded.
Propofol EC50 to induce LOC was higher in patients in the follicular phase than those in the luteal phase (4.17 vs 3.58 µg ml(-1), P<0.05). Progesterone correlated significantly with Ceprop at LOC. Emergence time was also longer in the follicular group than in the luteal group (6.5 vs 5.0 min, P<0.05).
During general anaesthesia, patients in the luteal phase of the menstrual cycle had a lower propofol EC50 for LOC and a shorter emergence time compared with those in the follicular phase. Differences in progesterone levels between menstrual phases may contribute to these anaesthetic effects. Registry number of clinical trial ChiCTR-RCH-12002755.
研究发现月经周期中不同水平的女性性激素会影响中枢神经系统。本研究的目的是探讨丙泊酚诱导意识丧失（LOC）的半数（50%）有效效应浓度（EC50）在月经周期的黄体期和卵泡期是否存在差异。
选取22例在全身麻醉下行妇科手术的患者（卵泡期）和20例患者（黄体期）纳入研究。采用丙泊酚靶控输注（TCI）进行麻醉。初始靶效应室丙泊酚浓度（Ceprop）为3.5μg/ml，通过上下序贯法每隔4分钟以0.5μg/ml的步长进行调整以达到LOC。以脑电双频指数引导丙泊酚TCI维持麻醉。分析女性性激素与LOC时预测的Ceprop之间的相关性，并记录麻醉苏醒时间。
卵泡期患者丙泊酚诱导LOC的EC50高于黄体期患者（4.17 vs 3.58μg/ml，P<0.05）。孕酮与LOC时的Ceprop显著相关。卵泡期组的苏醒时间也比黄体期组长（6.5 vs 5.0分钟，P<0.05）。
在全身麻醉期间，月经周期黄体期的患者与卵泡期患者相比，丙泊酚诱导LOC的EC50较低，苏醒时间较短。月经周期之间孕酮水平的差异可能导致这些麻醉效果。临床试验注册号：ChiCTR-RCH-12002755。
