1.5 ml罗哌卡因用于小儿超声引导下正中神经阻滞半数有效配置浓度的研究

Median effective dilution concentration of 1.5 ml ropivacaine for ultrasound‑guided median nerve block in young children

目的Dixon序贯法测定1.5 ml罗哌卡因用于超声引导下正中神经阻滞的半数有效配置浓度(the median effec‑tive dilution concentration,EDC50)。方法选取拟于重庆医科大学附属儿童医院行狭窄性腱鞘炎手术的患儿,年龄1~3岁,ASA分级Ⅰ级或Ⅱ级,所有患儿均采用非气管插管全身麻醉复合正中神经阻滞麻醉。麻醉诱导后,在超声引导下行前臂正中神经阻滞,定位成功后注入1.5 ml罗哌卡因。采用Dixon序贯法,罗哌卡因起始浓度为0.2%,若阻滞成功,则下一例减少1个浓度梯度;若阻滞失败,则下一例增加1个浓度梯度,相邻浓度变化梯度为0.02%。记录患儿性别、ASA分级、年龄、体重、麻醉时间、正中神经直径、正中神经横截面积、术中是否使用补救药物、不良反应(如心动过缓、低血压、恶心、呕吐、瘙痒、呼吸抑制或气管痉挛等)发生情况,术后2、4、6、12 h随访并记录患儿改良加拿大东安大略儿童医院疼痛评分(modified Children's Hospital of Eastern Ontario Pain Scale,m‑CHEOPS)评估疼痛情况。采用中心等渗回归分析法计算罗哌卡因的EDC50和95%有效配置浓度(the 95%effective dilution concentration,EDC95)及其95%CI。结果共22例患儿纳入本研究。阻滞成功和阻滞失败的患儿性别比、ASA分级、年龄、体重、麻醉时间、正中神经直径与正中神经横截面积比较,差异均无统计学意义(P>0.05)。患儿的EDC50为0.11%(95%CI 0.09%~0.15%),EDC95为0.18%(95%CI 0.17%~0.26%)。所有患儿术中均无不良反应发生,术后2、4、6、12 h随访中m‑CHEOPS均<6分。结论单剂量1.5 ml罗哌卡因用于超声引导下正中神经阻滞患儿狭窄性腱鞘炎手术有效,1~3岁儿童的EDC50为0.11%(95%CI 0.09%~0.15%)、EDC95为0.18%(95%CI 0.17%~0.26%)。

Objective To determine the median effective dilution concentration(EDC_(50))of 1.5 ml ropivacaine for ultrasound-guided median nerve block by using a sequential method.Methods Children[American Society of Anesthesiologists(ASA)I or Ⅱ] aged 1-3 years who were scheduled for unilateral thumb sheath release surgery in Children's Hospital of Chongqing Medical University were enrolled.All children applied intravenous anesthesia combined with a median nerve block.After anesthesia in-duction,the ultrasound-guided median nerve block was applied.After localization,the total volume of ropivacaine was 1.5 ml and the test initial concentration was O0.2%according to the modified Dixon's up-and-down method.Based on the outcome of the preceding me-dian nerve block,a block of success or failure resulted in a 0.02%reduction or increase in concentration,respectively.Record the child's gender,ASA grade,age,weight,anesthesia time,median nerve diameter,and median nerve cross-sectional area,whether reme-dial medication is used during the surgery,whether there are any complications(such as bradycardia,hypotension,nausea,vomiting,itching,respiratory suppression,or tracheal spasm),and follow up at 2,4,6 h and 12 h after the surgery to record modified Children's Hospital of Eastern Ontario Pain Scale(m-CHEOPS).The EDC_(50),the 95%effective dilution concentration(EDC_(95)),and each 95%confidence interval(CI)of ropivacaine in ultrasound‑guided median nerve block was calculated with the centered isotonic regression meth‑od.Results Twenty‑two children scheduled for unilateral thumb sheath release surgery were enrolled.There were no significant dif‑ferences in sex ratio,ASA grade,age,weight,anesthesia time,median nerve diameter,and median nerve cross‑sectional area between the successful and failed patients(P>0.05).The EDC_(50) was 0.11%(95%CI 0.09%,0.15%),the EDC_(95) was 0.18%(95%CI 0.17%,0.26%),and no adverse events occurred.No adverse reactions occurred in all patients during the operation,and m‑CHEOPS were low‑er than 6 points at 2,4,6 h and 12 h postoperative follow‑up.Conclusions A single dose of 1.5 ml ropivacaine is an effective medication for ultrasound‑guided median nerve block in children undergoing unilateral thumb sheath release surgery.The EDC50 was 0.11%(95%CI 0.09%,0.15%)and the EDC_(95) was 0.18%(95%CI 0.17%,0.26%)in children aged 1‒3 years.