Dossi Roberto, Quadri Christian, Capdevila Xavier, Saporito Andrea
Anesthesia, Ospedale Regionale di Bellinzona e Valli Bellinzona, Bellinzona, Switzerland
Clinica Sant'Anna, Sorengo, Switzerland.
Reg Anesth Pain Med. 2025 Jan 14. doi: 10.1136/rapm-2024-106086.
During peripheral nerve blocks, inadvertent intraneural injection is not infrequent. Recently, with sonographic nerve swelling, it has been shown that intraneural injection can be detected as early as 0.4 mL. A new method based on injection pressure monitoring at the needle tip, the real pressure in the tissues, is compared with sonographic performance in early detection of intraneural injection.
This cadaver study was conducted on the upper limb of fresh cadavers. Senior anesthesiologists performed ultrasound guided intraneural injections of the nerves using a modified Visioplex needle with a fiberoptic sensor embedded. 12 injections were performed, two on each nerve (radial, ulnar, and median) for each anatomical preparation. 3 mL of saline methylene blue mix was injected at 10 mL/min. Recordings of ultrasound screen and pressure curves were blindly analyzed to evaluate nerve swelling and injection pressures.
An immediate increase in injection pressure from time zero was observed in all 12 intraneural injections, with similar trends. After only 0.2 mL, intraneural injection was clearly identified as the pressure curves had already risen to an average of 120 mm Hg (SD 5). Nerve swelling was observed in 10 of 12 injections (83%). This was evident after an average of 1.2 mL (SD 0.5). Following injections, dissection of specimens confirmed intraneural spread in all cases.
Pressure monitoring at the needle tip consistently showed a pressure rise from the onset of injection and proved to be a more sensitive and earlier indicator of intraneural injection than sonographic nerve swelling.
在周围神经阻滞过程中，意外的神经内注射并不罕见。最近，通过超声观察神经肿胀发现，早在注射0.4毫升时就能检测到神经内注射。本文将一种基于监测针尖注射压力（即组织中的实际压力）的新方法与超声在早期检测神经内注射方面的性能进行了比较。
本尸体研究在新鲜尸体的上肢进行。资深麻醉医生使用带有嵌入式光纤传感器的改良Visioplex针，在超声引导下对神经进行神经内注射。每种解剖标本在每条神经（桡神经、尺神经和正中神经）上进行2次注射，共注射12次。以10毫升/分钟的速度注射3毫升生理盐水亚甲蓝混合液。对超声屏幕记录和压力曲线进行盲法分析，以评估神经肿胀和注射压力。
在所有12次神经内注射中，从注射开始即刻观察到注射压力增加，趋势相似。仅注射0.2毫升后，由于压力曲线已升至平均120毫米汞柱（标准差5），神经内注射就被明确识别。12次注射中有10次（83%）观察到神经肿胀。平均注射1.2毫升（标准差0.5）后肿胀明显。注射后，标本解剖证实所有病例均有神经内扩散。
针尖压力监测始终显示从注射开始压力就升高，并且被证明是比超声神经肿胀更敏感、更早的神经内注射指标。
