0.375%罗哌卡因用于肥胖患者超声引导锁骨上臂丛神经阻滞的最低有效剂量

Minimum effective dose of 0. 375%ropivacaine for ultrasound-guided supraclavicular brachial plexus block in obesity patients

目的确定0.375%罗哌卡因用于肥胖和健康体重患者超声引导锁骨上臂丛神经阻滞的最低有效剂量（MED）。方法择期在超声引导锁骨上臂丛神经阻滞下行上肢手术患者60例,根据体重指数分为肥胖组和健康体重组,每组30例,ASA分级Ⅰ~Ⅱ级,均采用Dixon序贯法进行试验,第1例患者0.375%罗哌卡因起始剂量为30 m L,相邻剂量之间的比值为1.1。采用Probit概率单位回归法计算0.375%罗哌卡因用于肥胖及健康体重患者超声引导锁骨上臂丛神经阻滞的MED及其95%可信区间（95%CI）。结果 0.375%罗哌卡因用于肥胖患者超声引导锁骨上臂丛神经阻滞的MED为20.89 m L,95%CI为19.83~21.96 m L;健康体重MED为19.80 m L,95%CI为18.68~20.91 m L。结论 0.375%罗哌卡因用于肥胖和健康体重患者超声引导锁骨上臂丛神经阻滞的MED分别为20.89 m L和19.80 m L。

Objective To determine the minimum effective dose（ MED） of 0. 375% ropivacaine for ultrasound-guided supraclavicular brachial plexus block in obesity and healthy weight patients. Methods Sixty ASA Ⅰ ~Ⅱ patients scheduled for upper extremity surgery under ultrasound-guided supraclavicular brachial plexus block,were divided into obesity group and healthy body group based on body mass index with 30 cases each. The initial dose of0. 375% ropivacaine was 30 m L in the first patient and the ratio between the 2 successive doses was 1. 1. The MED and95% confidence interval（ CI） were calculated by up-and-down technique. Results The MED and 95% CI of 0. 375%ropivacaine for ultrasound-guided supraclavicular brachial plexus block were 20. 89 m L and 19. 83 ~ 21. 96 m L in the obesity patients,respectively. The MED and 95% CI of 0. 375% ropivacaine for ultrasound-guided supraclavicular brachial plexus block were 19. 80 m L and 18. 68 ~ 20. 91 m L in the healthy weight patients,respectively. Conclusion The MED of 0. 375% ropivacaine for ultrasound-guided supraclavicular brachial plexus block is 20. 89 m L in the obesity patients,and 19. 80 m L in the healthy weight patients.