Liu Zunyi, Zhou Xuelan, Zhu Jiang
Department of Anesthesiology, the Second Afffliated Hospital of Soochow University, Suzhou City, People's Republic of China.
Department of Anesthesiology, the First Afffliated Hospital of Ningbo University, Ningbo City, People's Republic of China.
Eur J Clin Pharmacol. 2025 Mar;81(3):419-428. doi: 10.1007/s00228-024-03800-8. Epub 2025 Jan 8.
In part I, measure the EC50 of sufentanil in obese and non-obese parturients combined with 0.1% ropivacaine and compare the differences. Similarly, in part II, measure the EC50 of ropivacaine in obese and non-obese parturients combined with 0.5 µg/ml sufentanil and compare the differences.
This study comprises two parts, with an initial intention to enroll 120 full-term primiparous women who underwent vaginal delivery and sought epidural analgesia. Each part includes an obese group (OA group, Obese Adults, defined as prepartum BMI≥29 kg/m) and a non-obese group (CON group, Control group, defined as 18.5<prepartum BMI<28 kg/m), with 30 participants in each. Both parts, for both obese and non-obese women, utilized an initial concentration of 0.1% ropivacaine with 0.5 µg /ml sufentanil. The initial concentration of sufentanil is 0.5 µg/ml. When the NRS score is ≤3 within 30min after analgesia, it is considered effective analgesia, and the concentration of sufentanil in the next parturients decreases by 0.05 µg/ml. Otherwise, the concentration of sufentanil in the next parturient will increase by 0.05 µg/ml. The second part uses the same method to measure the EC50 of ropivacaine (increase or decrease by 0.01%) in the OA group and CON group combined with 0.5 µg/ml sufentanil, with 30 participants in each group. EC50 measurements were performed through up-and-down sequential allocation, with effective analgesia defined as an NRS score ≤3, 30 min post-analgesia.
In part I, the EC50 of epidural sufentanil in the OA group was 0.090 µg/ml (95% CI, 0.0610.115µg/ml), and in the CON group, it was 0.170µg/ml (95% CI, 0.1170.219µg/ml). In part II, the EC50 of epidural ropivacaine in the OA group was 0.048% (95% CI, 0.0410.053%), and in the CON group, it was 0.070% (95% CI, 0.0640.075%). The secondary outcomes in both parts of the study showed no statistically significant differences.
Obese parturients exhibited significantly lower EC50 values for ropivacaine and sufentanil compared to non-obese parturients. Lower concentrations of both agents can be considered for labor analgesia in obese parturients.
在第一部分中，测量舒芬太尼与0.1%罗哌卡因联合使用时在肥胖和非肥胖产妇中的半数有效浓度（EC50），并比较差异。同样，在第二部分中，测量罗哌卡因与0.5μg/ml舒芬太尼联合使用时在肥胖和非肥胖产妇中的EC50，并比较差异。
本研究包括两个部分，最初打算招募120名接受阴道分娩并寻求硬膜外镇痛的足月初产妇。每个部分包括一个肥胖组（OA组，肥胖成年人，定义为产前体重指数（BMI）≥29kg/m²）和一个非肥胖组（CON组，对照组，定义为18.5＜产前BMI＜28kg/m²），每组30名参与者。在两个部分中，对于肥胖和非肥胖女性，均使用初始浓度为0.1%的罗哌卡因与0.5μg/ml舒芬太尼。舒芬太尼的初始浓度为0.5μg/ml。当镇痛后30分钟内数字评分量表（NRS）评分≤3时，视为镇痛有效，下一名产妇的舒芬太尼浓度降低0.05μg/ml。否则，下一名产妇的舒芬太尼浓度将增加0.05μg/ml。第二部分使用相同方法测量OA组和CON组与0.5μg/ml舒芬太尼联合使用时罗哌卡因的EC50（增加或减少0.01%），每组30名参与者。通过序贯上下法进行EC50测量，有效镇痛定义为镇痛后30分钟NRS评分≤3。
在第一部分中，OA组硬膜外舒芬太尼的EC50为0.090μg/ml（95%可信区间，0.0610.115μg/ml），CON组为0.170μg/ml（95%可信区间，0.1170.219μg/ml）。在第二部分中，OA组硬膜外罗哌卡因的EC50为0.048%（95%可信区间，0.0410.053%），CON组为0.070%（95%可信区间，0.0640.075%）。研究两个部分的次要结局均无统计学显著差异。
与非肥胖产妇相比，肥胖产妇罗哌卡因和舒芬太尼的EC50值显著更低。肥胖产妇分娩镇痛时可考虑使用更低浓度的这两种药物。
