Department of Anesthesia and Pain Management, University of Toronto, Toronto, Ontario, Canada.
Reg Anesth Pain Med. 2011 May-Jun;36(3):266-70. doi: 10.1097/AAP.0b013e318217a6a1.
Ultrasound (US) guidance, in some instances, can increase the success rate and reduce the onset and procedure times for peripheral nerve blockade compared with traditional nerve localization techniques. The presumptive mechanism for these benefits is the ability to accurately inject local anesthetic circumferentially around the target nerve. We aimed to determine whether ensuring circumferential spread of local anesthetic is advantageous for US-guided popliteal sciatic nerve block.
Sixty-four adult patients undergoing US-guided popliteal sciatic block for elective foot and ankle surgery were randomly assigned to 1 of 2 groups, circumferential or single-location injection. Using a short-axis nerve view and out-of-plane needle approach, the needle tip was advanced to the posterior external surface of the sciatic nerve. A 30-mL local anesthetic admixture (1:1 lidocaine 2%/bupivacaine 0.5% with 1:200,000 epinephrine) was injected either entirely at this location (single location) or incrementally at multiple locations to ensure circumferential spread around the sciatic nerve (circumferential). Sensory and motor functions were assessed by a blinded observer at predetermined intervals. The primary outcome was sensory block defined as loss of sensation to pinprick in the distribution of both tibial and common peroneal nerves at 30 mins after injection.
Sensory block was achieved in 94% of patients in the circumferential injection group compared with 69% in the single-location injection group (P = 0.010). There were no differences detected in block performance time, pain during block performance, or block-related complications between groups.
Ultrasound-guided circumferential injection of local anesthetic around the sciatic nerve at the popliteal fossa can improve the rate of sensory block without an increase in block procedure time or block-related complications compared with a single-location injection technique.
与传统神经定位技术相比，超声（US）引导在某些情况下可以提高外周神经阻滞的成功率并减少阻滞的起始和操作时间。这些益处的推测机制是能够准确地将局部麻醉剂环绕目标神经注射。我们旨在确定确保局部麻醉剂的圆周扩散是否有利于超声引导的腘窝坐骨神经阻滞。
64 名接受超声引导的腘窝坐骨神经阻滞的成年患者接受择期足部和踝关节手术，随机分为两组，即环形或单点注射组。使用短轴神经视图和平面外进针方法，将针尖推进坐骨神经的后外表面。将 30mL 局部麻醉剂混合物（2％利多卡因 1％/0.5％布比卡因与 1：200,000 肾上腺素）全部注入该位置（单点）或注入多个位置以确保坐骨神经周围的圆周扩散（环形）。盲法观察者在预定间隔评估感觉和运动功能。主要结局是感觉阻滞，定义为注射后 30 分钟时胫神经和腓总神经分布的刺痛感丧失。
环形注射组 94％的患者达到感觉阻滞，而单点注射组为 69％（P=0.010）。两组之间在阻滞性能时间、阻滞过程中的疼痛或阻滞相关并发症方面均无差异。
与单点注射技术相比，在腘窝处坐骨神经周围的超声引导下环形注射局部麻醉剂可以提高感觉阻滞的成功率，而不会增加阻滞程序时间或阻滞相关并发症。
