腰-硬联合麻醉时硬膜外腔注药升高平面的机制探讨

目的：探讨腰-硬联合麻醉时硬膜外腔注药升高阻滞平面的机制。方法：45例盆腔手术患者均采用腰-硬联合穿刺针行L2～3穿刺,蛛网膜下隙注入等入等比重的0.75%布比卡因2ml后硬膜外腔置管。患者随机分3组,每组15例,硬外不给药（A组）,蛛网膜下腔注药后15、20、25min经硬膜外导管给予0.5%布比卡因各3ml（B组）或0.9%NaCl溶液各3ml（C组）。结果：B组和C组温觉、痛觉与触觉最高阻滞平面均明显高于A组,B组和C组之间差异无统计学意义,B组和C组平面固定时间明显长于A组,B组和C组之间差异无统计学意义。结论：腰-硬联合麻醉时硬外腔注入麻药和0.9%NaCl溶液对阻滞平面无统计学差异,提示阻滞平面升高主要是由于容量效应引起。

Study on the mechanism to extend the plane during combined spinal and epidural anesthesia

Objective：To investigate the mechanism to extend the blocking plane during combined spinal and epidural anesthesia.Methods：Forty-five patients undergoing pelvic cavity surgery were randomly allocated to three groups with 15 cases each.In all patients,a tuohy needle（B.D） was introduced into the L2-3 epidural space,and 2 ml isobaric 0.75% burpivacaine was injected into subarachnoid space through spinal needle in touhy needle.Patient received no extrsdural injection（group A）,or extradural 0.5% bupivacaine 3 ml（group B） or saline 3 ml（group C） at 15,20,25 min after subarachnoid injection respectively.Results：The maximum level of temperature,algesthsis 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 significantly compared with that in group A（P0.01）.Conclusion：Effect of extradural injection in combined spinal epidural anesthesia on block level may be related to volume effect.