联合椎管内麻醉时硬膜外注药升高阻滞平面的机制研究

A Study on the Mechanism to Extend the Plane during Combined Spinal and Epidural Anesthesia

目的 :探讨联合椎管内麻醉时硬膜外注药升高阻滞平面的机制。方法 :30例下肢矫形手术患者均采用蛛网膜下隙与硬膜外联合穿刺针行L2～ 3 穿刺 ,蛛网膜下隙注入等比重的 0 75 %布比卡因 1 5ml后硬膜外置管。患者随机分成三组 ,每组 10例 :硬膜外不给药 (A组 ) ,蛛网膜下腔注药后 15、2 0、2 5分钟经硬膜外导管给予 2 %利多卡因各3ml(B组 )或生理盐水各 3ml(C组 )。结果 :B组和C组温度觉、痛觉与触觉最高阻滞平面均明显高于A组 ,B组与C组之间无显著性差异 ;B组和C组平面固定时间明显长于A组 ,B组与C组之间无显著性差异。结论 :联合椎管内麻醉时硬膜外注入局麻药与注入生理盐水对阻滞平面升高无显著性差异 ,提示阻滞平面升高主要是由于容量效应。

Objective:To investigate the mechanism to extend the blocking plane during combined spinal and epidural anesthesia.Methods:Thirty patients undergoing lower limb orthopedic surgery were randomly allocated to three groups with 10 cases each.In all patients,a Tuohy needle (B.D) was introduced into the L 2～3 epidural space, and 1 5ml isobaric bupivacaine(11 25mg) was injected into subarachnoid space through spinal needle in Touhy needle.Patient received no extradural injection(group A),or extradural 2% lidocaine 3ml (group B) or saline 3ml(group C) at 15,20,25min after subarachnoid injection respectively.Results:The maximum level of temperature,algesthesis and tough sensory block in group B and group C were significantly higher than those in group A.The onset time in group B and group C prolonged significicantly compared with that in group A( P< 0 01).Conclusion:Effect of extradural injection in combined spinal epidural anesthesia on block level may be related to volume effect.