数量化脑电图监测手术切皮时的镇痛强度

Quantitative electroencephalogram monitoring the depth of anesthesia during skin incision

为评价数量化脑电图（ＥＥＧ）反映镇痛强度的准确性，作者对６５例ＡＳＡⅠ级腹部手术患者，快速静脉诱导气管插管后，机械通气。麻醉维持：Ｏ２－Ｎ２Ｏ（１：２）－七氟醚吸入，切皮前不追加长效肌松药，监测ＴＯＦ。随机分为三组：七氟醚呼气末浓度分别为１％（Ⅰ组）、１．５％（Ⅱ组）、２％（Ⅲ组），至少维持１５ｍｉｎ。应用数量化脑电图监测手术切皮前、后３分钟脑电图（Ｆｐ１－Ａ１，Ｆｐ２－Ａ２）和平均动脉压（ＭＡＰ）、心率（ＨＲ）的变化以及患者的切皮反应改变。结果显示，切皮前数量化ＥＥＧ随七氟醚呼气末浓度增加，波谱边缘频率（ＳＥＦ）、中频率（ＭＦ）、双谱指数（ＢＩＳ）明显降低（Ｐ＜０．０１），δ波比率（δＲ）明显升高（Ｐ＜０．０１），ＭＡＰ仅Ⅰ组和Ⅲ组之间差异有显著意义（Ｐ＜０．０５），ＨＲ三组之间差异无显著意义。切皮反应者的ＳＥＦ、ＭＦ、ＢＩＳ明显高于无反应者，δＲ明显低于无反应者（Ｐ＜０．０１）。反应者切皮前、后的ＭＡＰ和ＨＲ变化差明显大于无反应者（Ｐ＜０．０１）。作者认为，ＥＥＧ数量化指标ＳＥＦ和ＢＩＳ能较准确地反映切皮前七氟醚镇痛强度，血流动力学与七氟醚呼气末浓度无相关性，因此不能反映切皮前七氟醚镇痛强度。

We investigated the EEG parameter changes of skin incision during different depth of sevoflurane/nitrous oxide analgesia.65 ASA physical status Ⅰ patients (aged 34±12yr) scheduled for elective abdominal surgery were studied. The tracheal of each patient was intubated and the lungs were ventilated. Patients were randomly assigned to one of three groups. Anesthesia was maintained with 1%(group Ⅰ n =25),1 5%(groupⅡ n =20) or 2% (groupⅢ n =20) end tidal sevoflurane concentration in 66% nitrous oxide.Each of the concentration levels was maintained for at least 15 minutes before surgical incision. The EEG electrodes were placed on each patient in a front oparietal montage (Fp1 A1, Fp2 A2) referred to Cz. EEG was recorded during 3 min period before incision.Hemodynamic variables were also monitored. Inadequate anesthetic depth was defined as patient movement in response to a 5 cm skin incision.The ventilation was controlled to maintain normocapnia (P ET CO 2 5±0 04kPa).The data were analysed using ANOVA, liner correlation analysis and t test.A significant difference between EEG parameters( SEF,BIS,) and skin incision responsive rate were found among the three concentration groups( P <0 01).There were no difference of hemodynamics among the three groups. Patients who moved at incision also had significantly higher SEF, BIS leveles compared to non movers( P <0 01).Quantitative EEG determinants were correlated well with the end tidal sevoflurane concentration and were a useful predictor of patient movement in response to skin incision during sevoflurane/nitrous oxide anesthesia.