The Effects of Dexmedetomidine on Intraoperative SSEP and MEP in Spinal Surgery

ZHU Juan; ZHU Minghui; HE Fan

Abstract：Objective To observe the effects of dexmedetomidine on intraoperative SSEP and MEP in spinal surgery. Methods Sixty patients scheduled for spinal surgery under general anesthesia were divided randomly and equally into the propofol group ( Group P) and the combined propofol and dexmedetomidine group ( Group D) . Patients in Group P only received propofol infusion ( plasma target concentration 2. 0~3. 5 μg/mL at induction and 2. 5~3. 5 μg/mL for maintainance) , patients in Group D received intravenous infusion of 0. 5 μg/kg dexmedetomidine 10min before propofol infusion. BIS was monitored and maintained at 45 ~55. MAP, HR, BIS, SSEP and MEP were recorded before induction of anaesthesia, 5 min, 30 min and 2 hr after tracheal intubation. Results The BIS values decreased, the latency of P38 and N45 prolonged, and the amplitudes of P38 and N45 were significantly depressed at T1, T2 and T3 compared to those at T0 (P<0. 05). The amplitude of P38 and N45 was lower and the latencty of P38 and N45 was longer in Group P than that in Group D (P<0. 05). There was no case that failed to detect the wave of MEP intraoperatively in this study. Conclusion Dexmedetomidine would not affect intraoperative SSEP and MEP monitoring in spinal surgery.