重度子痫前期产妇剖宫产蛛网膜下腔阻滞所需罗哌卡因半数有效量和95％有效量的研究

50% and 95% effective doses of ropivacaine for subarachnoid block in severe preeclamptic patients undergoing cesarean section

目的研究重度子痫前期产妇行剖宫产术时蛛网膜下腔使用罗哌卡因的ED50和95％有效量（95％effective dose，ED95）。方法250例行择期剖宫产术重度子痫前期产妇，采用随机数字表法双盲分为5组（每组50例），分别鞘内注射0．5％重比重罗哌卡因7．5、10．0、12．5、15．0、17．5mg。麻醉效果不好则硬膜外追加罗哌卡因。根据结果计算罗哌卡因的ED50和ED95记录罗哌卡因、去氧肾上腺素的用量和患者满意度。观察各组术中并发症发生情况及新生儿Apgar评分。结果蛛网膜下腔阻滞所需罗哌卡因ED50和ED95分别为9．3mg（95％CI：8．6—9．9mg）和14．9mg（95％CI：13．7～16．9mg）。各组10min后阻滞平面明显不同（P〈0．05）。15．0mg组、17．5mg组低血压发生率明显高于其他3组（P〈0．05）。7．5mg组、10．0mg组去氧肾上腺素用量低于其他3组，差异均有统计学意义（P〈0．05）。7．5mg组追加罗哌卡因用量明显高于其他组（P〈0．05）。其他副作用、患者满意度和新生儿Apgar评分各组差异无统计学意义（P〉0．05）。结论重度子痫前期产妇行蛛网膜下腔顿膜外联合麻醉时罗哌卡因的ED50和ED95分别为9．3mg和14．9mg。

Objective To examine the E50 and 95% effective dose （ED95） of ropivacaine for subarachnoid block in severe preeclamptic patients undergoing cesarean section. Methods This study enrolled 250 severe preeclamptic patients undergoing cesarean section. They were randomly divided into 5 groups respectively received 0, 7.5, 10.0, 12.5, 15.0 mg and 17.5 mg ropivacaine （n=50）. The use of ropivaeaine and phenylephrine, and patients＇ satisfaction, intraoperative complications, and the neonates＇ Apgar scores were documented. Results EDs0 and EDgs of ropivacaine for successful subarachnoid block were 9.3 mg （95%CI： 8.6-9.9 mg） and 14.9 mg （95%CI： 13.7-16.9 mg） respectively. The sensory block was significantly different among groups 10 min after intrathecal injection （P〈0.05）. The incidences of hypotension in group 17.5 mg and group 15.0 mg were higher than those in other 3 groups （P〈0.05）. The doses of phenylephrine in group 7.5 mg and group 10.0 mg were lesser than those in other 3 groups （P〈0.05）. The additional doses of ropivacaine in group 7.5 mg were higher than those in other 3 groups（P〈0.05）. There was no significant difference in patients＂ satisfaction and the Apgar score of neonates among four groups with different doses of ropivacaine （P〉0.05） . Conclusions Our study showed that the ED50 and ED95 of ropivacaine for subarachnoid block in severe preeclamptic patients undergoing elective cesarean delivery were 9.3 mg and 14.9 mg, respectively.