超声引导下坐骨神经阻滞的临床研究

Ultrasound examination and localization of the sciatic nerve

【目的】评价超声对坐骨神经显像及在坐骨神经阻滞中的定位作用，为进一步的临床应用提供依据。【方法】采用超声成像技术对11例膝屈肌痉挛患者行坐骨神经检查，并应用实时超声引导技术引导阻滞针到达神经，接通神经电刺激器确认为坐骨神经后，在坐骨神经周围注入1％的利多卡因8～10ml。观察并动态记录坐骨神经声像图特征，神经进针定位，最小的有效电刺激强度，注入利多卡因前后的痉挛改善情况等。【结果】超声能有效显示11例患者坐骨神经的走行及结构特征，显示率为100％。坐骨神经的实时超声引导穿刺1次成功率为72．72％，电刺激验证确定坐骨神经的最小有效电流强度为（0．27±0．1）mA，注射1％利多卡因后痉挛改善率为100％。【结论】初步的研究结果表明超声能清晰显示坐骨神经的走行及结构特征，能够准确穿刺定位神经，对坐骨神经阻滞治疗严重膝屈肌痉挛有潜在的应用价值。

[Objective] To evaluated the usefulness of ultrasound in identifying the sciatic nerve in the lower extremity and in guiding needle advancement to target before nerve stimulation. [Methods] In this observational study, 11 patients with chronic hemiplegia and severe spasticity underwent sciatic nerve examination using a curved ultrasound probe in the 5 MHz. Thereafter, an insulated block needle was advanced under direct ultrasound guidance to reach the target nerve, which was further confirmed by electrical stimulation.The patients performed by injecting 1% lidocaine （8- 10 ml） into the sciatic nerve. The quality of sciatic nerve images, ease of needle to nerve contact, threshold stimulating current were recorded. The knee flexor spasticity were scored clinically and were assessed before and after block of the sciatic nerve. [ Results] The sciatic nerve was successfully identified on ultrasound .The target nerve was easily visualized by ultrasound in 100% of the patients. The success rate of puncture for one time was 72.72% and elieiting motor contractions with a threshold current occured at （0.27 ± 0.1） mA. All patients had improvement of knee flexor spasficity after the injection. [ Conclusions] These preliminary data show that a 5 MHz ultrasound probe provides good quality sciatic nerve imaging in the location. Ultrasound- assisted sciatic nerve localization is potentially valuable for clinical sciatic nerve blocks.