不同方式给予右美托咪定对腰丛联合坐骨神经阻滞下老年患者单侧下肢手术中镇静和血流动力学的影响

目的：探讨不同方式给予右美托咪定对腰丛联合坐骨神经阻滞下老年患者下肢手术中镇静和血流动力学的影响。方法单侧下肢手术老年患者80例，年龄60～85岁，ASA分级Ⅰ～Ⅲ级，随机分为四组（每组20例）：右美托咪定诱导量0．5μg／kg，静脉输注15 min，0．3μg／（kg·h）维持（D1组）；右美托咪定按0．5μg／（kg·h）剂量持续输注至术毕（D2组）；咪达唑仑诱导量0．015 mg／kg，静脉输注15 min，0．1 mg／（kg·h）维持（M组）及等量生理盐水组（C组）。在麻醉前（T0）、静脉给药即刻（T1）、静脉给药15 min（T2）、30 min（T3）和术毕（T4）时各时间点分别测定MAP、HR、SpO2和脑电双频指数（BIS）值，并进行OAA／S镇静评分。结果与C组和T0比较，镇静评分在D1和M组的T2、T3、T4和D2组的T4时间点较低，BIS值在D1和M组的T2、T3、T4及D2组的T3、T4时间点较低（P ＜0．05）；与D1组和T0时间点比较，MAP在C和M组的T2、T3、T4及D2组的T2时间点升高（P ＜0．05）；与C、M组和T0时间点比较，HR在D1组的T2、T3、T4和D2组的T3、T4时间点降低（P＜0．05）。结论对于腰丛联合坐骨神经阻滞下行下肢手术的老年患者，给予一定诱导剂量后持续输注右美托咪定可使患者较快达到镇静状态，且血流动力学平稳。

Effects of different dexmedetomidine administrations on sedation and hemodynamics during com-bined lumbar plexus and sciatic nerve blocks in elderly patients undergoing unilateral lower limb surgery

Objective To investigate the effects of different dexmedetomidine administrations onsedation and hemodynamics during combined lumbar plexus and sciatic nerve blocks in elderly patients un dergoing unilateral lower limb surgery.Methods Eighty ASAⅠor Ⅲ patients,aged 60 ~85 years,re ceived lower limb surgery and were randomly divided into four groups（n =20 in each group）.Patients re ceived 0.5 μg/kg of dexmedetomidine induction for 15 min and 0.3 μg/（kg·h）of dexmedetomidine forcontinuous infusion in group D1 ,0.5 μg/（kg·h）of continuous dexmedetomidine infusion in group D2,0.015 mg/kg of midazolam induction for 15 min and 0.2 mg/（kg·h）of continuous midazolam infusion ingroup M,and equal volume of normal saline in group C.The mean arterial pressure（MAP）,heart rate（HR）,SpO2 ,OAA/S scores and bispectral index（BIS）values were recorded before the anesthesia（T0 ）,atthe time of intravenous administration（T1 ）,15 min after intravenous administration（T2 ）,30 min after in travenous administration（T3 ）and the end of operation（T4）.Results Compared with group C at T0 ,OAA/S scores were lower in group D1 and group Mat the time of T2 ,T3 and T4 and group D2 at the timeof T4（P 〈0.05）.BIS values were lower in group D1 and group Mat the time of T2 ,T3 and T4 and groupD2 at the time of T3 and T4 （P 〈0.05）.Compared with group D1 at T0,MAP was increased in group C andgroup Mat the time of T2 ,T3 and T4 and group D2 at the time of T2 （P 〈0.05）.Compared with group Cand group Mat T0,HR was decreased in group D1 at the time of T2 ,T3 and T4 and group D2 at the time ofT3 and T4 （P 〈0.05）.Conclusion Certain doses of dexmedetomidine induction followed by continuousinfusion can provide rapid sedation and stable hemodynamics in elderly patients undergoing lower limb sur gery during combined lumbar plexus and sciatic nerve blocks.