选择性脊神经后根切断术中背根神经刺激监测的麻醉深度控制

Optimal anesthesia depth for direct dorsal rootlet stimulation during selective posterior rhizotomy

目的探讨选择性脊神经后根切断术(selective posterior rhizotomy,SPR)中脊髓背根电刺激检查过程中适宜的麻醉深度。方法选择全麻下接受SPR术的痉挛性脑瘫患者20例,观察术中患者接受脊神经后根电刺激检查过程中,不同麻醉深度(A点:患者BIS<60;B点:BIS值在60～69;C点:BIS值在70～80;D点:BIS>80)对电刺激阈值(electroshock threshold,ST)及脊髓背根电刺激检查对患者循环的影响,以及脊髓背根电刺激是否可导致患者出现抬头、呛咳、上肢活动等反应情况。结果 A点时,患者ST值最高,其脊髓背根电刺激过程中患者循环波动明显,需加大电刺激强度或降低麻醉深度方能完成检查过程;B点和C点患者接受电刺激检查过程中循环相对稳定,ST值均在0.2～0.6mA,两组间比较差异无统计学意义,此两组患者多无需调整麻醉深度即可顺利完成电刺激检查过程;D点时,患者在接受电刺激检查过程中不能耐受,循环波动显著,且多发生抬头、呛咳、上肢活动等反应。结论随着电刺激强度增加可引起患者的循环波动,因而SPR手术中需要合适的麻醉深度,以在保证患者舒适的同时避免过强电刺激引发不良反应,虽然存在个体差异,但开始实施电刺激时患者适宜的BIS值在60～75。

Objective To evaluate optimal anesthesia depth for direct dorsal rootlet stimulation with intraoperative electrophysiological monitoring during selective posterior rhizotomy. Methods Twenty patients with spastic cerebral palsy scheduled for selective posterior rhizotomy were enrolled into the study. All patients received direct dorsal rootlet stimula- tion with intraoperative electrophysiological monitoring at different anesthesia depth （BIS values under 60 as point A, BIS values between 60 and 69 as point B, BIS values between 70 and 80 as point C, and BIS values over 80 as point D）. Elec- troshock threshold （ST）, patients hemodynamic values and their response to the stimulations were recorded to evaluate the optimal anesthesia depth. Results ST values at point A were the highest among all the patients. Patients hemodynamic values at this point changed remarkably during direct dorsal rootlet stimulation, and ST values must be augmented or re- duce the anesthesia depth to finish the intraoperative electrophysiological monitoring. Hemodynamic values at point B and C kept stable during direct dorsal rootlet stimulation, ST values were between 0.2 mA and 0.6 mA, and there was no signif- icant difference at point B and C. Intraoperative electrophysiological monitoring finished successfully without anesthesia depth modulation in these two groups. At point D, patients couldn＇t tolerate the direct dorsal rootlet stimulation. Head rais- ing, cough and limb movement were common during the intraoperative electrophysiological monitoring, anesthesia depth must be turned down. Conclusions During intraoperative electrophysiological monitoring, direct dorsal rootlet stim- ulation may lead to different responses, so proper anesthesia depth is needed to ensure the patients comfort and to avoid the excessive stimulation intensity. For BIS values, the optimal anesthesia depth for direct dorsal rootlet stimulation during selective posterior rhizotomy should be between 60 and 75, but individual differences must be considered.