右旋美托咪啶增强局麻药对坐骨神经的阻滞作用

目的：随机、双盲观察右旋美托咪啶对局麻药行腘窝处坐骨神经阻滞麻醉效能的影响.方法：60例行单侧大隐静脉曲张手术的病人,随机分为右旋美托咪啶联合局麻药组（DL组）和0.9％氯化钠溶液联合局麻药组（SL组）2组,每组30例.采用超声引导行患侧胭窝坐骨神经分叉处阻滞和股神经、闭孔神经阻滞.DL、SL 2组坐骨神经阻滞用药分别为0.5mL（50μg）右旋美托咪啶或0.5 mL 0.9％氯化钠溶液＋2％利多卡因9.5 mL＋0.75％罗哌卡因10 mL,共20 mL.记录2组患侧的腓肠外侧皮神经、腓肠神经、腓浅神经、腓深神经、足底外侧神经、足底内侧神经的感觉起效时间和胫神经、腓总神经的运动起效时间;感觉、运动持续时间.结果：DL组腓肠神经、腓浅神经、足底外侧神经、足底内侧神经感觉起效时间显著短于SL组,两组比较差异有统计学意义（P＜0.05）;DL组腓肠外侧皮神经、腓深神经与SL组感觉起效时间差异无统计学意义（P＞0.05）;DL组胫神经、腓总神经运动起效时间显著短于SL组（P＜ 0.05）;DL组感觉、运动持续时间显著长于SL组（P＜0.05）.结论：右旋美托咪啶增强局麻药行坐骨神经阻滞时的麻醉效能.

Dexmedetomidine enhances the efficacy of local anesthetics on sciatic nerve block

Objective： A randomized and double-blinded observation anesthesia efficacy of dexmedetomidine on local anesthetics for popliteal sciatic nerve block. Methods： Sixty patients who undergone unilateral great saphenouse vein surgery were randomly divided into two groups： Group DL and Group SL （n=30）. Ultra- sound-guided sciatic nerve block proximal to the neural bifurcation at the popliteal fossa combined with femoral and obturator nerve block were performed in all patients. The sciatic nerve was blocked with 2% lidocaine 9.5 mL and 0.75% ropivacaine 10 mL combined with 0.5 mL （50 ~tg） dexmedetomidine or 0.5 mL saline in Group DL and Group SL respectively, totally 20 mL. The sensory onset time of lateral sural cutaneous nerve （CN）, sural nerve （SN）, superficial peroneal nerve （SPN）, profundum peroneal nerve （PPN）, lateral plantar nerve （LPN） and medial plantar nerve （MPN） were recorded; the motor onset time of tibial nerve and common peroneal nerve were recorded; furthermore,the duration of sensory and motor block were recorded. Results： The sensory onset time of SN, SPN, LPN and MPN in Group DL were significantly faster than those in Group SL （P〈0.05）, where- as the sensory time of CN and SPN were not different between the two groups （P〉0.05）; the motor onset time of tibial nerve and common peroneal nerve in Group DL were significantly faster than those in Group SL （P〈0.05）; the duration of sensory and motor block were significantly faster in Group DL than those in Group SL （P〈0.05）. Conclusion： Dexmedetomidine enhances the anesthesia efficacy of local anesthetics on sciatic nerve block.