鞘内注射氢吗啡酮对罗哌卡因用于剖宫产半数有效量及麻醉效果的影响

Effects of intrathecal injection of hydromorphone on ED_(50) of ropivacaine in patients undergoing cesarean section

目的观察鞘内注射氢吗啡酮复合罗哌卡因用于剖宫产的麻醉效果,探讨氢吗啡酮对罗哌卡因半数有效量(ED_(50))的影响。方法选择ASAⅠ~Ⅱ级于腰-硬联合麻醉下行剖宫产手术的患者44例,按随机数字表法分为氢吗啡酮复合罗哌卡因组(RH组)及单纯罗哌卡因组(R组),每组22例。采用序贯试验法:首例患者RH组鞘内注射氢吗啡酮75μg及0.5%罗哌卡因15 mg重比重混合液3 mL,R组鞘内注射0.5%罗哌卡因15 mg重比重混合液3 mL,根据前一例患者麻醉效果有效或无效,降低或提高后一例患者鞘内给药1个剂量梯度,剂量梯度设定为1:1.1。序贯法计算两组罗哌卡因用于剖宫产腰麻的ED_(50)。结果 RH组罗哌卡因ED_(50)为9.06 mg,其95%CI为8.74~9.38 mg;R组罗哌卡因ED_(50)为11.27 mg,其95%CI为10.93~11.62 mg。两组罗哌卡因ED_(50)比较差异有统计学意义(P<0.01)。给药4、8、15 min后,R组MAP明显降低,且低于RH组(P<0.01),但均处于正常范围内。结论氢吗啡酮75μg复合罗哌卡因用于剖宫产腰麻时,可降低罗哌卡因的ED_(50),且术中生命体征更稳定,并可缩短局麻药起效时间,延长其作用时间。

Objective To observe the anesthesia effects of intrathecal injection of hydromorphone combined with ropivacaine in patients undergoing cesarean section and discuss the influence of hydromorphone on half-effectiveness dose（ ED50） of ropivacaine. Methods Forty-four patients（ ASAⅠ ~Ⅱ） undergoing cesarean section combined spinal-epidural anesthesia（ CSEA） were randomly divided into two groups： ropivacaine combined with hydromorphone group（ group RH） and ropivacaine group（ group R）. The sequential test method was used： the first patient in group RH received intrathecal injection of mixture（ 3 mL, containing 75 μg hydromorphone and 15 mg of 0. 5% ropivacaine）,while patients in group R received 0. 5% ropivacaine 15 mg only. According to whether the anesthesia of the former case was effective or not, the dose of the next case was decreased or increased, the dose gradient was set at 1： 1. 1. ED50 was determined by Dixon＇s sequential method. Results The ED50 of ropivacaine was 9. 06 mg in group RH（ 95% CI：8. 74 ~ 9. 38 mg）,while ED50 of ropivacaine in group R was 11. 27 mg（ 95% CI： 10. 93 ~ 11. 62 mg）; there was significant difference in ED50 between the two groups（ P 0. 01）. The level of MAP in group R decreased at 4,8and 15 min after treatment,which was lower than that of group RH, and the levels of MAP were within the normal limits（ P 0. 01）. Conclusion Hydromorphone（ 75 μg） combined with ropivacaine for intrathecal injection in patients undergoing cesarean section can reduce the ED50 of ropivacaine,with more stable intraoperative vital signs,which can accelerate the onset of local anesthetics and prolong the action time of local anesthetics.