背景:先前的研究已经探讨了罗哌卡因用于肥胖产妇分娩硬膜外镇痛的中位有效浓度(EC50)。然而,90%有效浓度(EC90)的临床意义尚不清楚.本研究旨在确定和比较硬膜外罗哌卡因用于有和无肥胖产妇分娩镇痛的剂量-反应曲线。方法:根据体重指数(BMI)将产妇分为两组:N组,由BMI<30kg/m2的产妇和O组组成,由BMI>30kg/m2的产妇组成。在每一组中,患者随机接受五种浓度中的一种(0.0375%,0.075%,0.1125%,0.15%,或0.1875%)硬膜外罗哌卡因用于分娩镇痛。用15mL指定浓度的负荷剂量诱导镇痛。在基线和给药后30分钟记录视觉模拟评分(VAS)评分,以使用公式[(基线VAS疼痛评分-30分钟时的VAS疼痛评分)/基线VAS疼痛评分]×100%计算反应(%)。通过非线性回归分析确定EC50和EC90值。结果:罗哌卡因的EC50和EC90值分别为0.061%(95%置信区间[CI],N组0.056%-0.066%)和0.177%(95%CI,0.152%-0.206%),O组0.056%(95%CI,0.051%-0.061%)和0.161%(95%CI,0.138%-0.187%),分别。两组之间的EC50和EC90值没有显着差异(p值分别为0.121和0.351。结论:总之,在这项研究的参数范围内,我们的发现表明肥胖,以平均BMI值为30.9为特征,对硬膜外罗哌卡因用于分娩镇痛的EC50和EC90值没有显着影响。需要进一步的研究来阐明罗哌卡因与BMI值较高的肥胖之间的剂量反应关系。临床试验注册:https://www.chictr.org.cn/showproj.html?proj=190747,标识符ChiCTR2300073273。
Background: Previous studies have explored the median effective concentration (EC50) of ropivacaine for labor epidural analgesia in parturients with obesity. However, the clinical relevance of the 90% effective concentration (EC90) remains unclear. This
study aimed to determine and compare the dose-response curve of epidural ropivacaine for labor analgesia between parturients with and without obesity. Methods: Parturients were divided into two groups based on body mass index (BMI): group N, consisting of parturients with BMI <30 kg/m2, and group O, consisting of parturients with BMI >30 kg/m2. Within each group, the patients were randomized to receive one of five concentrations (0.0375%, 0.075%, 0.1125%, 0.15%, or 0.1875%) of epidural ropivacaine for labor analgesia. Analgesia was induced with a loading dose of 15 mL of the assigned concentration. Visual analogue scale (VAS) scores were recorded at baseline and 30 min post-dose to calculate the response (%) using the formula [(baseline VAS pain score-VAS pain score at 30 min)/baseline VAS pain score] ×100%. The EC50 and EC90 values were determined via nonlinear regression analysis. Results: The EC50 and EC90 values of ropivacaine were 0.061% (95% confidence interval [CI], 0.056%-0.066%) and 0.177% (95% CI, 0.152%-0.206%) in group N and 0.056% (95% CI, 0.051%-0.061%) and 0.161% (95% CI, 0.138%-0.187%) in group O, respectively. No significant differences were observed in the EC50 and EC90 values between the two groups (p-values = 0.121 and 0.351, respectively. Conclusion: In conclusion, within the parameters of this
study, our findings suggest that obesity, characterized by a mean BMI value of 30.9, does not significantly influence the EC50 and EC90 values of epidural ropivacaine for labor analgesia. Further investigations are warranted to elucidate the dose-response relationship between ropivacaine and obesity with higher BMI values. Clinical
trial registration: https://www.chictr.org.cn/showproj.html?proj=190747, Identifier ChiCTR2300073273.