METHODS: Intraoperative mTc-MEP amplitudes, mTc-MEP area under the curves (AUC), and anesthetic and physiological measurements were collected retrospectively from the records of 108 consecutive patients undergoing elective spinal surgery. Pharmacological parameters of interest included propofol and opioid concentration, ketamine and noradrenaline infusion rates. Physiological parameters recorded included mean arterial pressure (MAP), bispectral index (BIS), heart rate, hemoglobin O 2 saturation, temperature, and Et co2 . A forward selection procedure was performed using multivariable mixed model analysis.
RESULTS: Data from 75 (69.4%) patients were included. MAP and BIS were significantly associated with mTc-MEP amplitude ( P < .001). mTc-MEP amplitudes increased by 6.6% (95% confidence interval [CI], 2.7%-10.4%) per 10 mm Hg increase in MAP and by 2.79% (CI, 2.26%-3.32%) for every unit increase in BIS. MAP ( P < .001), BIS ( P < .001), heart rate ( P = .01), and temperature ( P = .02) were significantly associated with mTc-MEP AUC. The AUC increased by 7.5% (CI, 3.3%-11.7%) per 10 mm Hg increase of MAP, by 2.98% (CI, 2.41%-3.54%) per unit increase in BIS, and by 0.68% (CI, 0.13%-1.23%) per beat per minute increase in heart rate. mTc-MEP AUC decreased by 21.4% (CI, -38.11% to -3.98%) per degree increase in temperature.
CONCLUSIONS: MAP, BIS, heart rate, and temperature were significantly associated with mTc-MEP amplitude and/or AUC. Maintenance of BIS and MAP at the high normal values may attenuate anesthetic effects on mTc-MEPs.
方法:术中mTc-MEP振幅,mTc-MEP曲线下面积(AUC),从108例接受择期脊柱手术的连续患者的记录中回顾性收集麻醉和生理测量结果。感兴趣的药理学参数包括异丙酚和阿片类药物浓度,氯胺酮和去甲肾上腺素输注率。记录的生理参数包括平均动脉压(MAP),脑电双频指数(BIS),心率,血红蛋白O2饱和度,温度,和Etco2。使用多变量混合模型分析进行正向选择程序。
结果:纳入了75例(69.4%)患者的数据。MAP和BIS与mTc-MEP振幅显著相关(P<.001)。mTc-MEP振幅增加6.6%(95%置信区间[CI],MAP每增加10mmHg2.7%-10.4%),BIS每增加一个单位2.79%(CI,2.26%-3.32%)。MAP(P<.001),BIS(P<.001),心率(P=0.01),和温度(P=0.02)与mTc-MEPAUC显著相关。MAP每增加10mmHg,AUC增加7.5%(CI,3.3%-11.7%),BIS每单位增长2.98%(CI,2.41%-3.54%),每分钟心跳增加0.68%(CI,0.13%-1.23%)。温度每升高一度,mTc-MEPAUC降低21.4%(CI,-38.11%至-3.98%)。
结论:地图,BIS,心率,和温度与mTc-MEP振幅和/或AUC显着相关。将BIS和MAP维持在高正常值可能会减弱对mTc-MEP的麻醉作用。