0.2%罗哌卡因用于超声引导下学龄前儿童臂丛神经阻滞的半数有效容量研究

Study of median effective volume of 0.2%ropivacaine for ultrasound-guided brachial plexus block in children

目的用序贯法测定0.2%罗哌卡因用于超声引导下学龄前儿童臂丛神经阻滞的半数有效容量。方法选取首都医科大学附属北京儿童医院采用臂丛神经阻滞下行肱骨髁上骨折手术的学龄前儿童26例,其中男14例,女12例,体重10.1~28.4 kg,ASAⅠ~Ⅱ级,在超声引导下行臂丛神经阻滞,定位成功后注入0.2%罗哌卡因。采用Dixon序贯法进行试验,0.2%罗哌卡因起始容量为1 mL/kg,若阻滞效果完全,则下一例减少容量0.1 mL/kg;若阻滞不完全,则下一例增加容量0.1 mL/kg。采用Probit概率单位回归法计算超声引导下臂丛神经阻滞时,0.2%罗哌卡因的半数有效容量及其95%可信区间。结果行肱骨髁上骨折手术学龄前儿童经超声引导下臂丛神经阻滞时,0.2%罗哌卡因的半数有效容量为0.298 mL/kg,其95%可信区间为0.188~0.727 mL/kg。结论0.2%罗哌卡因在超声引导下学龄前儿童肱骨髁上骨折手术中臂丛神经阻滞的半数有效容量为0.298 mL/kg。

Objective To determine the median effective volume(EV50)of 0.2%ropivacaine for ultrasound-guided brachial plexus block(BPB)in children.Methods Twenty-six preschool children,14 males and 12 females,American Society of Anesthesiologists physical status Ⅰ~Ⅱ,weighing 10.1-28.4 kg,scheduled for humeral supracondylar fractures surgery sequentially received an ultrasound-guided BPB with 0.2%ropivacaine.The modified Dixon s up-and-down method was adopted in the test with the initial dose 1 mL/kg.Based on the outcome of the preceding block,a positive or negative block resulted in a 0.1 mL/kg reduction or increase in volume,respectively.The EV50 and 95%confidence interval(95%CI)of 0.2%ropivacaine were calculated by Probit Regression method.Results In the ultrasound-guided brachial plexus block in preschoolers with humeral supracondylar fractures surgery,the EV50 and 95%CI of 0.2%ropivacaine was 0.298 mL/kg and 0.188-0.727 mL/kg.Conclusion The EV50 of 0.2%ropivacaine for an ultrasound-guided brachial plexus block in preschool children with humeral supracondylar fractures surgery was 0.298 mL/kg.