He Lin, Wang Xuan, Zheng Shan
Department of Anaesthesiology, Children's Hospital of Fudan University, Shanghai, China.
Department of Surgery, Children's Hospital of Fudan University, Shanghai, China.
Paediatr Anaesth. 2018 Nov;28(11):1043-1049. doi: 10.1111/pan.13503. Epub 2018 Oct 3.
We investigated the minimal alveolar concentration (MAC) of sevoflurane associated with the occurrence of isoelectric electroencephalogram in 50% of children under steady-state conditions (MAC IE). The MAC IE was determined in 100% oxygen and with the addition of 50% nitrous oxide or after the injection of fentanyl.
Seventy-two children (ASA I or II, age 3-8 years) undergoing elective surgery were allocated to one of three groups: in 100% oxygen (group O ), in 50% oxygen and 50% nitrous oxide (group N O), or in 100% oxygen with a bolus of 3 μg/kg fentanyl (group FENTANYL). The state of isoelectric EEG was considered as significant when a burst suppression ratio of 100% lasted for >1 minute. The MAC IE was determined by the Dixon's up-and-down method after a 15-minute period with a stable endtidal concentration of sevoflurane. The concentration of sevoflurane was determined by the electroencephalogram of the previous patient: increase of 0.2% if isoelectric EEG were absent or decrease of 0.2% if isoelectric EEG were present.
The MAC IE in group O (MAC IE ) was 5.30 (5.12-5.48)% (median [95% CI]). The MAC IE in group N O (MAC IE ) was 5.83 (5.67-5.99)%. The MAC IE in group FENTANYL (MAC IE ) was 5.37 (5.21-5.53)%, which was close to MAC IE .
The MAC IE of sevoflurane calculated in 100% O was 5.30% in children. Addition of 50% N O modestly increased MAC IE of sevoflurane, while 3 μg/kg fentanyl had no effect on MAC IE of sevoflurane.
我们研究了在稳态条件下50%儿童出现等电位脑电图时七氟醚的最低肺泡浓度（MAC）（MAC IE）。MAC IE是在100%氧气中并添加50%氧化亚氮或注射芬太尼后测定的。
72例择期手术的儿童（ASA I或II级，年龄3 - 8岁）被分为三组之一：100%氧气组（O组）、50%氧气和50%氧化亚氮组（N₂O组）或100%氧气加3μg/kg芬太尼推注组（芬太尼组）。当爆发抑制率100%持续超过1分钟时，等电位脑电图状态被视为有意义。在七氟醚呼气末浓度稳定15分钟后，采用Dixon上下法测定MAC IE。七氟醚浓度根据前一位患者的脑电图确定：如果没有等电位脑电图则增加0.2%，如果有等电位脑电图则降低0.2%。
O组的MAC IE（MAC IEₒ）为5.30（5.12 - 5.48）%（中位数[95%CI]）。N₂O组的MAC IE（MAC IEₙ₂ₒ）为5.83（5.67 - 5.99）%。芬太尼组的MAC IE（MAC IEբₑₙₜₐₙᵧₗ）为5.37（5.21 - 5.53）%，与MAC IEₒ接近。
在儿童中，100%O₂中计算出的七氟醚MAC IE为5.30%。添加50%N₂O适度增加了七氟醚的MAC IE，而3μg/kg芬太尼对七氟醚的MAC IE没有影响。
