右旋美托咪啶对全麻患者脑电双频谱指数及靶控输注异丙酚用量的影响

Dexmedetomidine decreases propofol requirements during generalized anaesthesia: effect on bispectral index

目的 观察新型α2 肾上腺素受体激动剂右旋美托咪啶对全麻患者脑电双频谱指数 (BIS)及靶控输注 (TCI)异丙酚用量的影响。方法 选择全麻下行甲状腺次全切除术的年轻患者 30例 (ASAⅠ～Ⅱ级 ) ,将其随机双盲分为两组 :D组 (n =15 ) :右旋美托咪啶 0 4 μg/kg,用生理盐水稀释成 5ml静脉泵注 (5min) ,C组 (对照 ,n=15 ) :生理盐水 5ml,方法同D组 ,监测其BIS ,HR ,MAP ,SpO2 。结果 ①两组患者一般情况基本相同 ,麻醉前BIS分别为 92± 1和 90± 2 ;②D组给予右旋美托咪啶后BIS出现进一步下降 ,由 5 1± 2降至 4 2± 16 ,C组则仍为 5 1± 3,无明显变化。D组减少异丙酚的Ct值 ,由 (3 6± 0 5 ) μg/ml减少至 (2 8± 1 3) μg/ml,可使BIS恢复 ,C组维持不变 ;异丙酚的用量D组比C组减少 8%～ 14 % (P <0 0 5 ) ;③D组使用右旋美托咪啶后HR明显减慢 ,由 (78 2± 13 0 )次 /min减为 (6 4 4± 8 8)次 /min ;MAP无明显变化 ;④术后苏醒期D组患者呼吸恢复时间 ,睁眼时间及拔管时间与C组相似 (P >0 0 5 ) ,患者拔管时烦躁的现象明显减少。结论 右旋美托咪啶可产生明显镇静效应 ,能使BIS进一步降低 。

Objective To evaluate the influence of dexmedetomidine(Dex) on the bispectral index(BIS) and its potential dose-sparing effect on propofol. Methods Thirty adult patients of ASA class Ⅰ～Ⅱ who were scheduled for elective thyroidectomy were monitored with BIS, HR, MAP and pulse oximeter monitors continuously before and during anesthesia. Results Administration of Dex resulted in a decrease in the BIS from (51±2) to (42±16)(P<0.01), which allowed a reduction of propofol target concentration from(3.6±0.5)μg/ml to(2.8±1.3)μg/ml(P<0.01) to maintain the BIS. During subsequent surgery, propofol requirement was reduced by 8%～14%(P<0.05) in the Dex group. Conclusion The increase in anaesthetic depth induced by Dex can be measured with bispectral EEG analysis and allows reduction of propofol dose for maintanence of same depth of anaesthesia.