Effects of ropivacaine and sufentanil on maternal blood oxytocin levels during neuraxial of labor

Abstract

Background: Regional block for analgesia during early labor and throughout labor may have the adverse effect of weakening labor force or delaying labor. Determining ways to reduce this adverse effect is essential for clinical practice in the field. Aim: To compare the effect of ropivacaine and sufentanil drugs on maternal blood oxytocin levels during spinal or epidural analgesia during labor and to dentify the most suitable alternative for pain relief. Materials and Methods: We enrolled 90 women who were first-time pregnancy (4 experimental group - ABCD, 1conrol group - E) for this study that was conducted by randomized controlled clinical trial design. Participants admitted to the Maternity Department of the AfÏliated Hospital of Inner Mongolia Medical University from June to October 2023 were selected and each group has got 18 participants. In the control group (group E), 18 women who did not undergo labor pain relief at their own request were included in the study. Results: There were no significant differences in mean age (p=0.855), height (p=0.145), and body mass index (p=0.327) of 90 pregnant women in 5 groups. There was no difference in labor pain intensity when the cervix was dilated to 3 cm for all participants, p=0.143, and the reduction in pain intensity in the experimental groups after the use of the combination of labor pain relief method+drugs was significantly different (p<0.001). But the combination of pain relief methods and drugs used in 4 experimental groups (group A-13.71±2.44 hours, group B-14.77±1.94 hours, group C-13.31±1.49 hours, group D-13.95±1.74 hours, group E-13.26±1.91 hours) had no effect on the duration of labor compared to the control group (p=0.150). ANOVA analysis was also used to compare the differences in the blood oxytocin levels of the participants involved in the study, and there was no difference (p=0.561) in determining the oxytocin level when the first sample was taken during the cervix was 3 cm dilated. However, in the 4 experimental groups, 15 minutes after the use of pain relief methods and drugs and after 30 minutes in the control group, the 2nd blood sample was taken to determine the level of oxytocin. Also, the effect of inhibiting the release of oxytocin was ranked in the order of the group with the lowest from the highest group: B>D>A>C (p<0.001). Sufentanil+epidural analgesia in group C showed adequate relief of labor pain and minimal inhibition of oxytocin release (p<0.001). Conclusion: We determined that the use of the lowest dose combination of pain relief methods and drugs did not have an effect on prolonging the duration of labor. Epidural sufentanil analgesia has been shown to be a safe and reliable method with minimal reduction in blood oxytocin levels and minimal impact on duration labor.