Potency of epidural ropivacaine in inhibiting breakthrough pain in primiparae undergoing epidural labor analgesia
10.3760/cma.j.cn131073.20230220.01207
- VernacularTitle:硬膜外注射罗哌卡因抑制初产妇硬膜外分娩镇痛时爆发痛的效力
- Author:
Peng JIANG
1
;
Shuni HUANG
;
Xiangdong WANG
;
Yuanyan TU
Author Information
1. 广东省东莞市妇幼保健院麻醉科，东莞 523000
- Keywords:
Amides;
Analgesia, obstetrical;
Analgesia, epidural;
Breakthroughpain;
Dose-response relationship, drug
- From:
Chinese Journal of Anesthesiology
2023;43(12):1451-1453
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To determine the potency of epidural ropivacaine in inhibiting breakthrough pain in primiparae undergoing labor analgesia with programmed intermittent epidural bolus (PIEB).Methods:American Society of Anesthesiologists Physical Status classification Ⅰ or Ⅱ primiparae of full-termpregnancy, with a singleton fetus in vertex presentation, aged ≥18 yr, with body mass index < 30 kg/m 2, presenting with breakthrough pain during labor analgesia with PIEB, were enrolled in this study. Ropivacaine 10 ml was epidurally administered, and the concentration was determined by up-and-down sequential allocation. The initial concentration was set at 0.15% in the first patient in each group. Each time the concentration increased/decreased in the next patient depending on whether the patients showed breakthrough pain relief, and the ratio between the two successive doses was 0.9. The criterion of breakthrough pain relief was defined as numerical rating scale score < 4 points within 30 min after epidural injection of ropivacaine. The median effective concentration (EC 50) and 95% confidence interval of ropivacaine in inhibiting breakthrough pain were calculated by Dixon-Massey′s method. Results:Twenty-six patients were finally included in this study.The EC 50 (95% confidence interval)of ropivacaine in inhibiting breakthrough pain was 0.102% (0.088%-0.117%). Conclusions:The EC 50(95% confidence interval) of epidurally administered ropivacaine 10 ml is 0.102%(0.088%-0.117%) when used for inhibiting breakthrough pain during labor analgesia with PIEB in primiparae.
