THE RELATIONSHIP OF TACHYPHYLAXIS IN EPIDURAL ANESTHESIA AND CSF pH CHANGE

硬膜外麻醉中的心动过速与脑脊液pH变化的关系

• 批准号: 07671673
• 负责人: KATSUKI Hiroshi
• 金额: $ 1.47万
• 依托单位: Miyazaki Medical College
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07671673/
• 关键词: epidural anesthesia; tachyphylaxis; csf pH

This study was carried out to elucidate the mechanism of tachyphylaxis in clinical epidural anesthesia. The hypothesis was that repetitive administration of large dose local anesthetics may increase csf pH will cause failure in csf pH regulation, result in csf pH increase, which prevent transdural influx of unionized forms of local anesthetic molecule. Then abrupt tachyphylaxis may take place.Although, we demonstrated that extracellular procaine perfusion resulted in pHi increase in crayfish giant axon with only 1-4 mM,epidurally administered 2-5% procaine solution did not affect csf pH in rat. And, because of difficulty in settlement of epidural catheter in rat epidural space, we could not achieve stable epidural anesthesia in rats, so no evidence of tachypylaxis was observed in rats.As to the fact that no effect of epidural procaine on csf pH,we considered that the rat csf volume is too large to be affected by epidurally administered small dose of procaine, or transdural procaine influx is not so large as we expected.

本研究旨在阐明临床硬膜外麻醉中快速反应的机制。假设重复使用大剂量局麻药可使脑脊液pH升高，导致脑脊液pH调节失效，导致脑脊液pH升高，从而阻止局部麻醉药分子的统一形式经硬膜外流入。虽然我们证明了细胞外普鲁卡因灌流只引起大鼠巨轴突phi增加1-4 mm，但硬膜外注射2-5%普鲁卡因溶液并不影响脑脊液的pH值。由于硬膜外导管在大鼠硬膜外间隙难以固定，我们无法在大鼠体内实现稳定的硬膜外麻醉，因此在大鼠身上没有观察到快速松弛的证据。对于硬膜外普鲁卡因对脑脊液pH没有影响的事实，我们认为大鼠的脑脊液容量太大，不能被硬膜外小剂量普鲁卡因影响，或者说通过硬膜外普鲁卡因的内流没有我们预期的那么大。