右美托咪定对老年患者罗哌卡因胸椎旁阻滞半数有效浓度的影响  

Effect of dexmedetomidine on the medium effective concentration of ropivacaine for thoracic paravertebral block in aged patients

作　　者：叶伟光[1] 王天龙[1] 

机构地区：[1]首都医科大学宣武医院麻醉科,北京100053

出　　处：《国际麻醉学与复苏杂志》2016年第11期964-967,共4页International Journal of Anesthesiology and Resuscitation

摘　　要：目的评价右美托咪定（dexmedetomidine，Dex）对老年患者超声引导下胸椎旁阻滞罗哌卡因半数有效浓度（median effective concentration，EC。）的影响。方法选择胸腔镜下行肺叶切除术老年患者60例，年龄65～79岁，ASA分级Ⅱ、Ⅲ级，拟在超声引导下行胸椎旁阻滞。采用随机数字法分为两组（每组30例）：对照组（C组）和Dex组（D组）。C组神经阻滞用药仅为罗哌卡因；D组神经阻滞用药为罗哌卡因和0．75μg／kgDex的混合液。罗哌卡因初始浓度为0．5％，相邻浓度比值为1．2，若阻滞效果评定为优良，则下一例采用低一级浓度；若阻滞效果评定为差，则下一例采用高一级浓度。采用Probit概率单位回归法计算两组罗哌卡因胸椎旁阻滞的EC50及其95％置信区间（confidence interval，CI）。结果C组超声引导下罗哌卡因的EC50为0．42％，95％CI为0．40％。0．45％；Dex组罗哌卡因的EC50为0．35％，95％CI为0．32％～0．37％。结论Dex可降低罗哌卡因椎旁阻滞的EC50。Objective To investigate effect of dexmedetomidine （Dex） on the medium effective concentration （EC50） of ropivacaine for ultrasound-guided thoracic paravertebral block. Methods Sixty ASA 11 or m patients, aged 65-79 y, scheduled for lobectomy under video-assisted thoracoscopic surgery, requiring ultrasound-guided thoracic paravertebral block, were randomly assigned into 2 groups （n=30）： control group （group C） and Dex group （group D）. Paravertebral block was performed by using only ropivacaine in group C. In group D the mixture of ropivacaine and 0.75 μg/kg Dex was injected for the block. The initial concentration of ropivacaine was 0.5% and the ratio between the two successive concentrations was 1.2. If the block was effective, the next patient received a lower dose of ropivacaine, or if ineffective, a higher dose was given to the next patient. The EC50 and 95% confidence interval （CI） of ropivacaine were determined by using probit regression method. Results The EC50 of ropivacaine was 0.42% and 95%CI was 0.40%-0.45% in group C,The EC50 of ropivacaine was 0.35% and 95%CI was 0.32%-0.37% in group D. Conclusions The combined use of Dex can decrease the EC50 of ropivacaine for ultrasound-guided thoracic paravertebral block.

关 键 词：老年 右美托咪定 椎旁阻滞 

分 类 号：R614[医药卫生—麻醉学]