Antwerp University Hospital, Antwerp, Belgium.
University of Barcelona, Barcelona, Spain.
Anaesthesia. 2017 Apr;72(4):461-469. doi: 10.1111/anae.13787. Epub 2017 Feb 10.
This study evaluated the incidence of nerve puncture and intraneural injection based on the needle approach to the nerve (direct vs. tangential). Two expert operators in regional anaesthesia performed in-plane ultrasound-guided nerve blocks (n = 158) at different levels of the brachial plexus in cadavers, aiming either directly for the nerve (n = 77) or tangentially inferior to the nerve (n = 81). After reaching the outer limit of the nerve, the needle was intentionally advanced approximately 1 mm in both approaches, and 0.2-0.5 ml of saline was injected. Each operator classified (in real time) the needle tip and injectate as intraneural or not. Video clips showing the final position of the needle and the injection were evaluated in the same manner by seven independent expert observers who were blinded to the aims of this study. In addition, 20 injections were performed with ink for histological evaluation. Intraneural injections of saline were observed by the operator in 58% (45/77) of cases using the direct approach and 12% (10/81) of cases using the tangential approach (p < 0.001). The independent observers agreed with the operator in a substantial number of cases (Cohen's kappa index 0.65). Histological studies showed intraneural spread in 83% (5/6) of cases using the direct approach and in 14% (2/14) of cases using the tangential approach (p = 0.007). No intrafascicular injections were observed. There was good agreement between the operators' assessment and subsequent histological evaluation (Cohen's kappa = 0.89). Simulation of an unintentional/accidental advancement of the needle 'beyond the edge' of the nerve suggests significantly increased risk of epineural perforation and intraneural injection when a direct approach to the nerve is used, compared with a tangential approach.
本研究基于针接近神经的方式（直接与切线）评估了神经穿刺和神经内注射的发生率。两位区域麻醉专家在尸体上进行臂丛神经的平面内超声引导神经阻滞（n=158），目的是直接针对神经（n=77）或神经下方切线（n=81）。到达神经的外限时，两种方法都将针故意推进约 1 毫米，然后注入 0.2-0.5 毫升生理盐水。每位操作者实时将针尖和注射物分类为神经内或非神经内。七个独立的专家观察者以同样的方式评估显示最终针尖位置和注射位置的视频片段，他们对本研究的目的一无所知。此外，还进行了 20 次墨水注射进行组织学评估。操作者观察到直接进针法 58%（45/77）的情况下发生盐水神经内注射，而切线进针法 12%（10/81）的情况下发生（p<0.001）。独立观察者在大量情况下与操作者一致（Cohen's kappa 指数 0.65）。组织学研究显示，直接进针法 83%（5/6）的情况下发生神经内扩散，切线进针法 14%（2/14）的情况下发生（p=0.007）。未观察到神经内束内注射。操作者评估与后续组织学评估之间存在良好的一致性（Cohen's kappa=0.89）。模拟针尖“超出”神经边缘的无意/意外推进表明，与切线进针法相比，直接针对神经进针法时，神经外膜穿孔和神经内注射的风险显著增加。
