蔡敬怡　白岚　周雁

[摘要] 目的 探讨0.375%罗哌卡因用于老年患者超声引导下“三叶草法”腰丛阻滞的半数有效剂量（ED50）。 方法 选择2015年7月～2016年3月北京积水潭医院32例行择期下肢矫形骨科手术的老年患者进入本次研究，ASA分级为Ⅰ～Ⅲ级，在超声引导下行“三叶草法”腰丛神经阻滞。使用序贯法进行研究，初始剂量为0.375%罗哌卡因15 mL，若阻滞效果完全，下一例减少5 mL；否则，增加5 mL。运用Probit概率单位回归法研究0.375%罗哌卡因用于老年患者超声引导下“三叶草法”腰丛阻滞50%患者阻滞有效的剂量。 结果 0.375%罗哌卡因用于超声引导下老年患者“三叶草法”腰丛神经阻滞的ED50為23.12 mL，95%可信区间为18.6～28.1 mL。 结论 0.375%罗哌卡因用于老年患者超声引导下“三叶草法”腰丛阻滞的ED50为23.12 mL。

[关键词] 老年患者；三叶草法；腰丛神经；神经阻滞；半数有效剂量

[中图分类号] R614 [文献标识码] A [文章编号] 1673-7210（2016）12（a）-0085-04

The median effective dose of ultrasound guided "shamrock method" lumbar plexus block with 0.375% Ropivacaine in elderly patients

CAI Jingyi BAI Lan ZHOU Yan

Department of Anesthesia， Beijing Jishuitan Hospital， Beijing 100035， China

[Abstract] Objective To determine the median effective dose （ED50） of ultrasound-guided "shamrock method" lumbar plexus block with 0.375% Ropivacaine in elderly patients. Methods 32 cases of elderly patients were enrolled from July 2015 to March 2016 in Beijing Jishuitan Hospital， whom underwent the elective lower limb surgery. The patient ASA grade was classified as Ⅰ-Ⅲ grade. Every patient enrolled in the study will be underwent the ultrasound-guided lumbar plexus block using the "shamrock method". The sequential method was used in the study， and the initial dosage of 0.375% Ropivacaine was 15 mL. If the block effect was completed， 5 mL of 0.375% Ropivacaine would be decreased for the next case； otherwise， an increase of 5 mL was applied. Probit regression study method was used to calculate the ED50. Results ED50 of 0.375% Ropivacaine for ultrasound-guided lumbar plexus block with "shamrock method" in elderly patients was 23.12 mL， 95% confidence interval for the 18.6-28.1 mL. Conclusion The lowest dosage of 0.375% Ropivacaine in 50% of elderly patients to achieve the ultrasound-guided lumbar plexus block with "shamrock method" is 23.12 mL.

[Key words] Elderly patient； Shamrock method； Lumbar plexus； Nerve block； ED50

超声引导下“三叶草法”腰丛阻滞是将低频探头放置于患者髂嵴头侧位置以获取腰椎及椎旁结构的超声横断面影像，包括腰丛神经的超声影像。进针时以平面内技术进针，将针尖准确地定位在腰丛神经旁，并在超声影像下实时观察局麻药围绕神经的扩散[1]。局麻药的剂量是影响神经阻滞成功率的重要因素之一，临床上常使用较高的局麻药浓度和较大的容量，以达到完善的阻滞效果。但高注入剂量可能增加硬膜外扩散和全身毒性反应的风险，而低剂量的风险是有可能引起阻滞失败[2]。曾有研究测试0.5%罗哌卡因用于成人“三叶草法”腰丛阻滞的最低有效剂量为20.5 mL[3]，一般随年龄递增局麻药用量会减少，但老年患者超声引导下“三叶草法”腰丛阻滞的最适用量尚不清楚。……