Hall David L, Weaver Joel, Ganzberg Steven, Rashid Robert, Wilson Stephen
Section of Primary Care, The Ohio State University College of Dentistry, Columbus, Ohio 43218-2357, USA.
Anesth Prog. 2002 Spring;49(2):56-62.
This single-blind controlled clinical study characterized the effects of 30-70% nitrous oxide (N2O) and 0.2-0.8% sevoflurane conscious sedation on quantitative electroencephalographic (EEG) readings of 22 healthy dental students as measured by the bispectral index (BIS). The study verified the 2 previously published BIS/N2O investigations showing no correlation between N2O dosage up to 70% and BIS. Observer's Assessment of Alertness and Sedation scores (OAA/S), however, correlated well with increasing doses of N2O from approximately 35 to 70%. A near linear dose-response relationship was established between OAA/S and end tidal (ET) sevoflurane concentrations of 0.4-0.7%. Only at the highest level of end tidal sevoflurane recorded, 0.7%, was statistically significant BIS depression seen. Subjects evaluated the acceptability of the sedative effect of the 2 gases, showing a slight preference for N2O. Comparable partial anterograde amnesia and sedation (OAA/S) were produced by both agents in administered concentrations of 40-70% N2O and 0.6-0.8% sevoflurane. Female subjects exhibited better memory and significantly less amnesia than males. No statistically significant changes occurred in any of the monitored vital signs. EMG readings demonstrated a statistically significant difference from control values only at the highest, 0.7%, ET concentration of sevoflurane. BIS does not appear useful for evaluating the level of nitrous oxide sedation in the dental setting but may have some value in assessing depth of sedation at deeper levels of sevoflurane sedation.
这项单盲对照临床研究,通过脑电双频指数(BIS)测量了30%-70%氧化亚氮(N₂O)和0.2%-0.8%七氟醚清醒镇静对22名健康牙科专业学生定量脑电图(EEG)读数的影响。该研究证实了之前发表的2项关于BIS/N₂O的调查,表明高达70%的N₂O剂量与BIS之间没有相关性。然而,观察者警觉与镇静评分(OAA/S)与N₂O剂量从约35%增加到70%有很好的相关性。在OAA/S与0.4%-0.7%的呼气末(ET)七氟醚浓度之间建立了近乎线性的剂量反应关系。仅在记录到的最高呼气末七氟醚水平(0.7%)时,才观察到具有统计学意义的BIS降低。受试者评估了这两种气体镇静效果的可接受性,结果显示对N₂O略有偏好。在40%-70%的N₂O和0.6%-0.8%的七氟醚给药浓度下,两种药物产生了相当的部分顺行性遗忘和镇静作用(OAA/S)。女性受试者比男性表现出更好的记忆力和明显更少的遗忘。所有监测的生命体征均未发生具有统计学意义的变化。肌电图读数仅在最高的呼气末七氟醚浓度(0.7%)时与对照值有统计学意义的差异。BIS似乎对评估牙科环境中氧化亚氮镇静水平没有用处,但在评估更深水平的七氟醚镇静深度时可能有一定价值。