Department of Anaesthesiology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei, China; MoE Key Laboratory for Biomedical Photonics, Collaborative Innovation Center for Biomedical Engineering, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei, China.
Br J Anaesth. 2020 Oct;125(4):548-559. doi: 10.1016/j.bja.2020.07.012. Epub 2020 Aug 15.
Circadian differences in the induction, maintenance, or emergence from volatile anaesthesia have not been well studied.
The minimal alveolar concentration (MAC) for preventing movement in response to a painful stimulus, MAC for loss of righting reflex (MAC), and MAC for recovery of righting reflex (MAC) in C57BL/6J male mice with isoflurane or sevoflurane exposure were measured during either the light or dark phase. Time to onset of loss of righting reflex (Time) and recovery of righting reflex (Time) upon exposure to 1 MAC of isoflurane or sevoflurane were determined. EEG was also monitored in the light and dark phase under isoflurane or sevoflurane exposure. The noradrenergic toxin N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4) was used to deplete noradrenergic neurones in the locus coeruleus to explore the impact of norepinephrine on these measurements.
MAC, Time, and MAC did not show light- or dark-phase-dependent variations for either isoflurane or sevoflurane exposure. However, MAC was higher and Time was shorter in the dark phase than in the light phase for both isoflurane and sevoflurane exposure. The EEG delta wave power was higher but theta wave power was lower in the light phase than that in the dark phase during the rest state and emergence of anaesthesia. These light- and dark-phase-dependent changes in emergence were abolished in DSP-4-treated mice.
Our data show that circadian differences exist during emergence but not during induction or maintenance of sevoflurane or isoflurane anaesthesia. The locus coeruleus noradrenergic system may contribute to these differences.
昼夜节律对挥发性麻醉剂的诱导、维持或苏醒的影响尚未得到充分研究。
在 C57BL/6J 雄性小鼠中，用异氟醚或七氟醚暴露，在光照或黑暗期测量预防对疼痛刺激产生运动的最低肺泡浓度（MAC）、失去翻正反射的 MAC（MAC）和恢复翻正反射的 MAC（MAC）。测定暴露于 1 MAC 异氟醚或七氟醚时失去翻正反射的时间（Time）和恢复翻正反射的时间（Time）。在光照和黑暗期监测异氟醚或七氟醚暴露下的脑电图（EEG）。使用 N-（2-氯乙基）-N-乙基-2-溴苯甲胺（DSP-4）作为去甲肾上腺素能毒素，耗竭蓝斑中的去甲肾上腺素能神经元，以探讨去甲肾上腺素对这些测量的影响。
MAC、Time 和 MAC 均未显示异氟醚或七氟醚暴露的光或暗期依赖性变化。然而，异氟醚和七氟醚暴露时，黑暗期的 MAC 较高，Time 较短。在休息状态和麻醉苏醒期间，光相的 EEG 德尔塔波功率较高，但 theta 波功率较低。在 DSP-4 处理的小鼠中，这些与光暗周期相关的苏醒变化被消除。
我们的数据表明，在七氟醚或异氟醚麻醉苏醒期间存在昼夜节律差异，但在诱导或维持期间没有差异。蓝斑去甲肾上腺素能系统可能对这些差异有贡献。
