Tsui B C, Gupta S, Finucane B
Department of Anesthesiology and Pain Medicine, University of Alberta and affiliated Hospitals (University of Alberta Hospital and Royal Alexander Hospital), 3B2.32 Walter Mackenzie Health Sciences Centre, Edmonton, Canada.
Can J Anaesth. 1999 Jul;46(7):675-8. doi: 10.1007/BF03013957.
To report the detection of subarachnoid and intravascular catheter placement using nerve stimulation through an epidural catheter.
Electrical stimulation (1-10 mA) was applied through the catheter. A positive motor response (truncal or limb movement) indicated that the catheter was in the epidural space. Absence of a motor response indicated that it was not. A low milliamperage (<1 mA) with bilateral response indicated subarachnoid placement. Intravascular catheter placement was indicated by a positive response to the test, which remains at or returns to the baseline levels (i.e. prior to any local anesthetic injection), despite the administration of local anesthetics. In the first patient, the test confirmed subarachnoid catheter placement during attempts at continuous spinal anaesthesia even though CSF could not be aspirated. Bilateral motor response in the legs was observed at 0.2 mA. In the second patient, inadvertent subarachnoid placement was detected during attempted lumbar epidural block by observing bilateral motor response in the legs at 0.3 mA. In the third patient, intravascular placement was suspected and confirmed by failure to obliterate the motor response despite repeated local anesthetic injection.
The new test provides objective information in managing epidural catheters when their position is uncertain.
报告通过硬膜外导管利用神经刺激检测蛛网膜下腔和血管内导管位置。
通过导管施加电刺激（1 - 10毫安）。阳性运动反应（躯干或肢体运动）表明导管位于硬膜外腔。无运动反应则表明不在硬膜外腔。低毫安数（<1毫安）且双侧有反应提示蛛网膜下腔置管。血管内置管的指征是对测试有阳性反应，即在注射局部麻醉药后，反应保持在或恢复到基线水平（即任何局部麻醉药注射前）。在首例患者中，尽管未能抽出脑脊液，但在连续脊麻尝试过程中该测试证实了蛛网膜下腔导管置管。在0.2毫安时观察到双侧腿部运动反应。在第二例患者中，在尝试腰段硬膜外阻滞时，通过在0.3毫安时观察到双侧腿部运动反应，检测到意外的蛛网膜下腔置管。在第三例患者中，尽管反复注射局部麻醉药，但运动反应未消失，怀疑并证实为血管内置管。
当硬膜外导管位置不确定时，这项新测试可为其管理提供客观信息。
