Bellinzona Regional Hospital, Bellinzona, Switzerland.
Service of Anaesthesia, Lugano Regional Hospital, Lugano, Switzerland.
Anaesthesia. 2019 Jan;74(1):64-68. doi: 10.1111/anae.14415. Epub 2018 Aug 22.
Alongside ultrasonic visualisation, measurement of injection pressure is an effective tool for reducing the risk of intraneural injection during peripheral nerve block. The aim of this study was to compare injection pressure profiles when measured along the injection line with the pressure measured directly at the needle tip using different rates of injection. A syringe pump delivered a 5-ml injection of saline into silicone gel at three different speeds (5 ml.min , 10 ml.min and 15 ml.min ). Fibreoptic pressure sensors recorded real-time pressure profiles of the injection pressure directly at the needle tip and along the injection line. A total of 15 injections were successfully performed, five for each injection rate, totalling 30 recorded pressure profiles. More rapid rates of injection caused peak pressure measured in-line to increase, whereas pressure measured at the needle tip remained constant (mean (SD) pressure in-line 30.76 (3.45) kPa vs. 72.25 (1.55) kPa and mean (SD) pressure at needle tip 19.92 (1.22) kPa vs. 20.93 (2.66) kPa at 5 ml.min and 15 ml.min , respectively). Injection pressure profiles showed that in-line pressure measurement failed to record precise real-time pressure changes occurring at the needle tip (mean (95%CI) pressure difference 10.8 (6.98-14.70) kPa vs. 51.2 (47.52-54.89) kPa for in-line and needle-tip measures, respectively). We conclude that, in order to accurately monitor the true injection pressure generated, independent from operator and injection parameters, measurement at the needle tip is necessary, as injection pressure measured along the injection line is an unreliable surrogate.
除了超声可视化之外，测量注射压力也是降低外周神经阻滞时神经内注射风险的有效工具。本研究的目的是比较在不同注射速度下，沿注射线测量的注射压力曲线与直接在针尖测量的压力曲线。注射器泵以 5ml.min-1、10ml.min-1 和 15ml.min-1 的三种不同速度将 5ml 生理盐水注入硅胶凝胶中。光纤压力传感器实时记录针尖和沿注射线的注射压力曲线。总共成功进行了 15 次注射，每种注射速度各 5 次，总共记录了 30 个压力曲线。更快的注射速度导致在线测量的峰值压力增加，而针尖测量的压力保持不变（在线压力分别为 30.76(3.45)kPa 和 19.92(1.22)kPa，针尖压力分别为 72.25(1.55)kPa 和 20.93(2.66)kPa，在 5ml.min-1 和 15ml.min-1 时）。注射压力曲线表明，在线压力测量无法记录针尖处实时发生的精确压力变化（在线测量和针尖测量的平均（95%CI）压力差分别为 10.8(6.98-14.70)kPa 和 51.2(47.52-54.89)kPa）。我们得出结论，为了准确监测产生的真实注射压力，独立于操作人员和注射参数，需要在针尖处进行测量，因为沿注射线测量的注射压力是不可靠的替代物。
