硬膜外预充生理盐水对脊麻罗哌卡因ED_(50)的影响

The effect of ED_(50) of the saline epidural injection in advance to the intrathecal injection of ropivacaine

目的采用序贯试验法评估硬膜外注射生理盐水对罗哌卡因鞘内注射运动神经阻滞达到Bromage 3级的半数有效剂量(ED50)的影响。方法腰硬联合麻醉下(CSEA)择期剖腹产手术产妇40例,随机分为,硬膜外注射生理盐水组,单纯罗哌卡因脊麻对照组。起始剂量均为7mg,剂量变化阶梯为1mg,鞘内注药20min后双下肢改良Bromage达到3级为有效。结果两组产妇术中最高阻滞平面及新生儿1min Apgar评分无显著差异(P>0.05),对照组低血压发生率及麻黄素用量较试验组差异有统计学意义(P<0.05)。罗哌卡因产生最大运动阻滞的ED50为7.93,95%CI为(7.46,8.77),硬膜外注射生理盐水后罗哌卡因产生最大运动阻滞的ED50为5.74,95%CI为(5.25,6.83),两者差异有统计学意义(P<0.05)。结论硬膜外注射生理盐水可降低罗哌卡因鞘内注射达到Bromage 3级时的ED50。

OBJECTIVE Using sequential trial method to assess the effect of 50% effective dose （EDs0） that the saline epidural injection to the intrathecal injection of ropivacaine with its block-level reached to Bromage 3 grade. METHODS The 60 elective caesarean mothers under Combined spinal anesthesia （CSEA） were randomly divided into the epidural injection of saline group and the control group of spinal ropivacaine alone. Starting dose are both 7mg, dose changes ladder lmg, a modified Bromage of both lower extremities. To the three grade was considered effective after 20 minutes intrathecal injection. RESULTS The highest block levels in the two groups of patients in maternal and newborn one minute Apgarscore were no significant difference（P 〉 0.05）. In the con- trol group, the incidence of hypotension and ephedrine consumption compared with the experimental group were significantly （P 〈 0.05）. Ropivacaine produced greatest motor block of the EDs0 of 7.93, 95 96 CI of （7.46, 8.77）, after the epidural injection of saline to produce the greatest movement of ropivacaine block of the EDs0 of 5.74,95% CI of （5.25,6.83）,the difference was statisticaUy significant （P〈0.05）.CONCLUSION Epidural injection of saline can reduce the the EDs0 of Bromage 3 grade of intrathecal ropivacaine reaching.