右美托咪定对颈椎前路手术运动诱发电位监测的影响

摘要

Objective To evaluate effect of dexmedetomidine for motor evoked potential monitoring during cervical spine surgery.Methods 90 patients undergoing single segment anterior cervical decompression were randomly assigned to a high-dose group,a low-dose group and a control group.The high-dose group was given a dosage of 1 μg/kg dexmede to midineat 10 minutes before the induction,while the low-dose group was given 0.5μg/kg dexmedetomidine and the control group received only the same dosage of saline injection.The amplitude and latency of motor evoked po-tential(MEP)was measured in three groups after drug administration,and the difference in amplitude and latency be-tween the three groups was compared.At the same time,the effective extraction rate of MEP after cervical decompres-sion was recorded and compared between the three group.Results The high dosage of dexmedetomidine significantly decreased the amplitude of MEP and prolonged the latency,with statistically significance when compared with the con-trol group.By contrast,the low dosage of dexmedetomidine had little influence on the amplitude and latency of MEP when compared with the control group.After the decompression of the cervical spine,the high dosage of dexmedetomi-dine resulted in the decrease of the effective extraction rate of ME while the low dose had little effect on the effective extraction rate of MEP.Conclusion Different dosage of dexmedetomidine will affect the MEP monitoring during spinal surgery.The high dosage causes the decreased of amplitude,the prolonged of latency and the decreased of effective ex-traction rate.Therefore,the dosage of dexmedetomidine should be maintained at 0.5~1.0 g/kg during anesthesia induc-tion,which will avoid the false-negative result of MEP and improve the accuracy of monitoring during surgery.%目的 评价麻醉药物右美托米啶对颈椎手术术中运动诱发电位检测的影响.方法 90例行单节段颈椎前路减压手术患者被随机分为高剂量用药组、低剂量用药组和对照组,每组30例.其中高剂量组诱导前10min给予1μg/kg右美托咪定负荷剂量泵注,低剂量组给予0.5μg/kg右美托咪定负荷剂量泵注,而对照组仅给予同剂量生理盐水泵注.药物泵注后,测量三组患者运动诱发电位(motor evoked potential,MEP)波幅和潜伏期,并比较三组之间的波幅和潜伏期改变是否有差异.同时,记录颈椎减压后MEP的有效引出率,比较不同浓度的右美托咪定是否对MEP的有效引出率有影响.结果 高剂量右美托咪定的负荷使用显著降低了MEP的波幅,延长了潜伏期,与对照组相比差异具有统计学意义(P<0.05);而低剂量的负荷使用对 MEP的波幅和潜伏期影响较小,与对照组相比差异无统计学意义(P>0.05).颈椎减压后高剂量右美托咪定导致MEP的有效引出率下降,而低剂量对 MEP的有效引出率影响较小,与对照组相比差异性较小.结论 不同剂量的右美托咪定会对脊柱手术术中MEP的监测产生影响,尤其是大剂量时会导致MEP的波幅下降,潜伏期延长和有效引出率显著下降,因此右美托咪定诱导应维持在0.5~1μg/kg之间,从而避免MEP监测假阴性的产生,提高术中MEP监测的准确性.