CAJ | 학술논문

目的：评价右美托咪定局部用药对罗哌卡因椎旁神经阻滞半数有效浓度（ EC50）的影响。方法拟在椎旁神经阻滞下行单侧乳腺肿块区段切除术女性患者48例，年龄20～64岁，BMI＜24 kg∕m2，ASA分级Ⅰ或Ⅱ级，采用随机数字表法分为2组（ n＝24）：罗哌卡因组（ R组）和罗哌卡因混合右美托咪定组（ RD组）。采用B超联合神经刺激仪引导定位，行术侧T4椎旁神经阻滞，分别局部注射罗哌卡因（ R组）或罗哌卡因与20μg右美托咪定混合液（ RD 组）20 ml，罗哌卡因初始浓度0．35％，按序贯法确定下一例罗哌卡因浓度，相邻浓度比值为1．2。采用Dixon?Massey法确定罗哌卡因EC50及其95％可信区间（95％CI）。结果 R组和 RD组罗哌卡因 EC50（95％CI）分别为0．27％（0．23％～0．30％）和0．22％（0．18％～0．25％）。与R组比较，RD组罗哌卡因EC50降低了19％。结论局部应用小剂量右美托咪定可对罗哌卡因椎旁神经阻滞产生显著的强化作用。
목적：평개우미탁미정국부용약대라고잡인추방신경조체반수유효농도（ EC50）적영향。방법의재추방신경조체하행단측유선종괴구단절제술녀성환자48례，년령20～64세，BMI＜24 kg∕m2，ASA분급Ⅰ혹Ⅱ급，채용수궤수자표법분위2조（ n＝24）：라고잡인조（ R조）화라고잡인혼합우미탁미정조（ RD조）。채용B초연합신경자격의인도정위，행술측T4추방신경조체，분별국부주사라고잡인（ R조）혹라고잡인여20μg우미탁미정혼합액（ RD 조）20 ml，라고잡인초시농도0．35％，안서관법학정하일례라고잡인농도，상린농도비치위1．2。채용Dixon?Massey법학정라고잡인EC50급기95％가신구간（95％CI）。결과 R조화 RD조라고잡인 EC50（95％CI）분별위0．27％（0．23％～0．30％）화0．22％（0．18％～0．25％）。여R조비교，RD조라고잡인EC50강저료19％。결론국부응용소제량우미탁미정가대라고잡인추방신경조체산생현저적강화작용。
Objective To evaluate the effect of dexmedetomidine administered locally on the median effective concentration ( EC50 ) of ropivacaine for paravertebral nerve block ( PVNB) . Methods Forty?eight ASA physical status Ⅰ or Ⅱ female patients, aged 20-64 yr, with body mass index<24 kg∕m2 , scheduled for elective unilateral segmental mastectomy under PVNB, were randomly divided into 2 groups ( n=24 each) using a random number table: ropivacaine group ( group R) and ropivacaine mixed with dexmedetomidine group ( group RD) . PVNB was performed at T4 on the operated side guided by ultrasound and nerve stimulator. Ropivacaine 20 ml and a mixture of ropivacaine and 20 μg dexmedetomidine 20 ml were injected locally in group R and group RD, respectively. The concentration of ropivacaine was determined by up?and?down sequential allocation. The initial ropivacaine concentration was set at 0. 35%, and the ratio between the two successive concentrations was 1. 2. The EC50 and 95%confidence interval of ropivacaine were calculated using Dixon?Massey method. Results The EC50 ( 95%confidence interval) of ropivacaine was 0.27% (0.23%-0.30%) and 0.22% (0.18%-0.25%) in group R and group RD, respectively. Compared with group R, the EC50 of ropivacaine was significantly decreased by 19% in group RD. Conclusion Small dose of dexmedetomidine administered locally can significantly enhance the efficacy of PVNB with ropivacaine.