Department of Anesthesia, Montreal General Hospital, and McGill University, Montreal, Quebec, Canada.
Reg Anesth Pain Med. 2011 Nov-Dec;36(6):548-52. doi: 10.1097/AAP.0b013e318235f566.
This prospective, randomized, observer-blinded trial compared a subepineural sciatic injection at the neural bifurcation (SUB group) and separate postbifurcation injections around the tibial and peroneal nerves.
Ultrasound-guided posterior popliteal sciatic nerve block was carried out in 50 patients. In the group that had separate postbifurcation injections around the tibial and peroneal nerves, the volume of local anesthetic (LA) (30 mL of lidocaine 1%-bupivacaine 0.25%-epinephrine 5 μg/mL) was divided equally between the tibial and peroneal nerves. In the SUB group, the 2 divisions were identified exactly at the neural bifurcation. In this location, both nerves can still be found inside a common epineural sheath. The entire volume of LA was injected between the 2 branches, inside the common sheath.A blinded observer recorded the success rate (complete sensory block at 30 mins) and onset time. The performance time, number of needle passes, and adverse events were also recorded. Total anesthesia-related time was defined as the sum of performance and onset times.
Compared with targeted injections around the tibial and peroneal divisions, a subepineural injection resulted in a higher success rate (84% vs 56%; P = 0.032) as well as improved efficiency (decreased performance/onset/total anesthesia-related times and fewer needle passes; all P ≤ 0.028). In the SUB group, we observed no instance of neural swelling. In 3 subjects randomized to separate injections, sonographic swelling of the tibial nerve occurred after the injection of 2 mL of LA. The needle was carefully withdrawn, and the injection completed uneventfully. In 45 patients, follow-up 1 week after the surgery revealed no sensory or motor deficit. Five subjects were lost to follow-up.
Compared with separate injections around the tibial and peroneal divisions, a single subepineural injection at the neural bifurcation provides a higher success rate and requires shorter performance, onset, and total anesthesia-related times. Further studies are required to validate the safety of the subepineural technique.
本前瞻性、随机、观察者盲法试验比较了在神经分叉处进行的神经下坐骨注射（SUB 组）和在胫神经和腓总神经周围进行的分叉后分别注射。
对 50 例患者进行超声引导的后腘窝坐骨神经阻滞。在胫神经和腓总神经周围进行分叉后分别注射的组中，局部麻醉药（LA）（30 毫升利多卡因 1%-布比卡因 0.25%-肾上腺素 5 μg/mL）的体积在胫神经和腓总神经之间等分。在 SUB 组中，2 个分支在神经分叉处精确地被识别出来。在这个位置，两个神经仍然可以在一个共同的神经外膜鞘内被找到。整个 LA 体积被注入两个分支之间，在共同鞘内。一名盲法观察者记录了成功率（30 分钟时完全感觉阻滞）和起效时间。操作时间、针数和不良事件也被记录下来。总麻醉相关时间定义为操作和起效时间的总和。
与靶向注射在胫神经和腓总神经分支周围相比，神经下注射具有更高的成功率（84%比 56%；P=0.032）和更高的效率（降低操作/起效/总麻醉相关时间和针数；所有 P≤0.028）。在 SUB 组中，我们没有观察到神经肿胀的情况。在 3 名被随机分到分别注射的患者中，在注射 2 毫升 LA 后，胫神经出现超声肿胀。小心地拔出针头，顺利地完成了注射。在 45 例患者中，术后 1 周的随访没有发现感觉或运动缺陷。5 名患者失访。
与胫神经和腓总神经分支周围的分别注射相比，在神经分叉处进行的单次神经下注射提供了更高的成功率，并且需要更短的操作、起效和总麻醉相关时间。需要进一步的研究来验证神经下技术的安全性。
