体感诱发电位监测在脊柱外科手术应用中的影响因素

目的分析体感诱发电位(SEP)监测在脊柱外科手术应用中的影响因素,探讨其预测指标,初步建立SEP指标波幅差值异常变化时出血量及平均动脉压的预测模型。方法回顾性分析接受多节段椎板切除减压手术的86例患者的SEP监测资料,以SEP波幅差值异常变化作为SEP受影响的指标,与性别、年龄、身高、体质量、平均动脉压范围、出血量、手术时间、皮下针电极导线长度、电磨钻应用情况、气磨钻应用情况、电动手术床电源接通情况等11个指标进行Pearson或Spearman相关分析及多元线性回归,筛选影响SEP的相关因素。结果 SEP指标(波幅差值P40/N50)和出血量(P0.05)、平均动脉压波动范围(P0.05)、电磨钻使用情况(P0.05)、气磨钻使用情况(P0.05)、电动手术床电源接通情况(P0.05)5个因素存在相关关系,而与性别(P0.05)、年龄(P0.05)、身高(P0.05)、体质量(P0.05)、手术时间(P0.05)、皮下针电极导线长度(P0.05)不具有相关关系。平均动脉压50 mm H(1 mm Hg g=0.133 k Pa)或在50 mm Hg左右波动时,以及出血量较多且1 249 m L时,SEP的波幅将明显发生变化,接近甚至会低于基线水平,与术中脊髓、神经损伤表现相似。结论出血量、平均动脉压范围、电磨钻使用情况、气磨钻使用情况和电动手术床电源接通情况是SEP指标(P40/N50)的影响因素。

Aplication of somatosensory evoked potential monitoring in spinal surgery: analysis of influential factors

Objective To analyze the factors influencing application of the somatosensory evoked potential(SEP) monitoring during spine surgery,explore the predictive index,and initially establish the prediction model of bleeding volume and mean arterial pressure when SEP amplitude changes abnormally. Methods SEP monitoring data of 86 patients undergoing the multisegmental laminectomy for decompression were analyzed retrospectively. Abnormal changing of the SEP amplitude deviation as the affected SEP index was analyzed with the gender,age,height,body weight,mean arterial pressure range, bleeding volume,operation time,wire length of hypodermic needle electrode,application of electric grinding drill,application of gas grinding drill,and surgical bed(whether being connected with electric power or not) by Pearson or Spearman correlation analysis,and the risk factors for SEP were selected by multiple linear regression analysis. Results Statistically significant linear relationships were demonstrated between the SEP index(the abnormal difference of P40/N50 amplitude) and the bleeding volume(P<0.05),the range of mean arterial pressure fluctuation(P<0.05),application of electric grinding drill(P<0.05),application of gas grinding drill(P<0.05),or the electric surgical bed whether was connected with electric power or not (P<0.05),respectively. Statistical significant linear relationships were not demonstrated between the SEP index(the abnormal difference of P40/N50 amplitude) and sex,age,height,body weight,operation time,or the wire length of percutaneous needle electrode(all P>0.05),respectively. The amplitude of the SEP would significantly change including close to or even lower than the baseline level when mean arterial pressure was less than 50 mmHg(1 mmHg=0.133 kPa) or at around 50 mmHg or bleeding volume more than 1 249 mL which was similar to the performance of intraoperative spinal cord or nerve injury. Conclusion The bleeding volume,range of mean arterial pressure,use or no use of electric grinding drill,use or no use of gas drill and whether the electric surgical bed is connected with electric power are influential factorsfor the abnormal changes of SEP index(P40/N50).