序贯法测定硬膜外分娩镇痛时罗哌卡因的EC_(50)和EC_(95)

The EC_(50) and EC_(95) of ropivacaine in epidural labor analgesia by sequential method

目的确定硬膜外分娩镇痛复合0.2μg/ml舒芬太尼时罗哌卡因的半数有效浓度(EC_(50))和95%最大有效浓度(EC_(95))。方法选择26例单胎足月初产妇,均在腰2~3间隙进行硬膜外腔穿刺和置管,将罗哌卡因起始浓度设为0.1%,背景输注速率5 ml/h,单次量5 ml,锁定时间30 min。试验采用序贯法,根据上1例产妇的疼痛评分,后1例产妇的罗哌卡因浓度上调或下调0.01%。采用Probit回归分析法计算罗哌卡因的EC_(50)和EC_(95)。记录不良反应发生率。结果最终24例产妇入选,24例产妇整个分娩镇痛期间无循环抑制、呼吸抑制发生,无胎心减速。新生儿娩出后1 min和5 min Apgar评分均为10分。在整个产程期间,有2名产妇恶心呕吐,发生率为8.33%;1位出现皮肤瘙痒(4.17%),无低血压、呼吸抑制及运动阻滞发生。参与研究的产妇24例,其中第1、2、3、4、6、7、10、12、13、15、16、18、19、22、24例临床有效,共15例;其余9例无效。罗哌卡因用于潜伏期硬膜外分娩镇痛的EC_(50)为0.06%,95%CI 0.05%~0.16%,EC_(95)为0.07%,95%CI 0.06%~0.11%。结论复合舒芬太尼0.2μg/ml时罗哌卡因用于潜伏期硬膜外分娩镇痛的EC_(50)为0.06%,EC_(95)为0.07%。不良反应少,起效快。

Objective To determine the half effective concentration(EC_(50))and 95%effective concentration(EC_(95))of ropivacaine for epidural labor analgesia combined with 0.2μg/ml sufentanil.Methods Twenty-six sing-fetalprimiparas receiving epidural analgesia were enrolled in this study.After a lumbar epidural catheter was placed at the L2-L3 interspace.Initial ropivacaine concentration of 0.1%,background infusion rate of 5 ml/h,single volume of 5 ml,locking time for 30 min.A sequential approach was used to increase or decrease the concentration of ropivacaine 0.01%based on the pain score of the previous woman.Probit regression analysis was used to calculate EC_(50)and EC_(95)of ropivacaine,and record incidence of adverse reactions.Result At last,24 cases of parturient women were included,and there was not circulation depression,respiratory depression and fetal heart deceleration during the whole labor analgesiain.Apgar scores were 10 at 1 min and 5 min after delivery.During labor,nausea and vomiting occurred in 2 women(8.33%).One patient showed pruritus(4.17%),without hypotension,respiratory depression or movement block.Twenty-four women were enrolled in the study,the 1,2,3,4,6,7,12,13,15,16,18,19,22 and 24 cases were effective,15 cases in total,and 9 cases were invalid.The EC_(50)and EC_(95)of ropivacaine for epidural labor analgesia were 0.06%,0.05%-0.16%,0.07%,0.06%-0.11%,respectively.Conclusion The EC_(50)and EC_(95)of ropivacaine with 0.2μg/ml of sufentanil for epidural analgesia during the incubation period were 0.06%and 0.07%respectively.The adverse reactions were less and efect quickly.