Effect Of Different Concentrations Of Ropivacaine Combined With Sufentanil On Epidural Analgesia For Vaginal Delivery

Objectives:To evaluate the analgesic efficacy of different concentrations of ropivacaine(0.125%or 0.08%w/v)combined with sufentanil(0.4μg·mL-1)in continuous epidural infusion for vaginal delivery in nulliparous pregnant women enrolled in tertiary hospital maternity wards.Methods:Nulliparous pregnant women,age between 20 to 35 years,with singleton pregnancy and full term of gestation admitted to Yan’an Hospital Affiliated to Kunming Medical University for vaginal delivery with epidural analgesia between December 2018 and June 2019 were recruited for this trial.These nulliparous women were randomly divided into two groups(60 subjects in each,n=60)according to the concentration of ropivacaine,high concentration group(group H,0.125%ropivacaine with 0.4 μg·mL-1 of sufentanil),low concentration group(group L,0.08%ropivacaine with 0.4μg·mL-1 of sufentanil).An epidural catheter was cephalic placed 4 cm through L2-3 intervertebral space and connected with an electronic infusion pump for epidural analgesia.After assisting the nulliparous women to be in the supine position,a test volume of 1%lidocaine 3 mL was medicated,without adverse effects,and then followed by a bolus of 6 mL of a mixture of ropivacaine combined with sufentanil 6 mL and maintenance with this mixture at the rate of 9 to 12 mL·h-1,aimed to control the pain perception sensory level at T10.Efficacy of epidural analgesia,visual analog scale(VAS)score in cm,heart rate(HR),mean arterial blood pressure(MAP),pulse oxygen saturation(SpO2),duration of labor,estimated blood loss volume,Apgar score of neonates,a request for midwifery and emergency changes to cesarean section,adverse events including fetal distress,hypoxia,nausea and vomiting,and postpartum hemorrhage were recorded.Results:There was no statistically significant difference in baseline values of age,height,weight,body mass index,gestational age,HR,and MAP between the two groups of nulliparous women(P>0.05).The estimated blood loss of women and Apgar score of neonates between the two groups were without significant difference(P>0.05).There was no statistical difference between the two groups in the satisfaction of the analgesic effect of the nulliparous women(P>0.05),but these women in Group H share with a lower VAS value than those in group L at 30 min after epidural analgesia(P<0.05).Although nulliparous women in group H has significantly longer the second stage of labor than those in group L(P<0.05),there was no significant difference in the duration between the first and third stage of labor between the two groups(P>0.05).The incidence of cesarean section and hypotension in nulliparous women in group H was higher than that in group L(P<0.05),but there was no significant difference in the appearance of hypoxia,nausea and vomiting between the two groups(P>0.05).None of the nulliparous women were suffered from postpartum hemorrhage in the current trial.Conclusions:Given the limited sample size and clinical practice,it does not support sufentanil combined with a higher concentration of ropivacaine is not well done in epidural labor analgesia.But,sufentanil combined with a lower concentration of ropivacaine can also be used well for continuous epidural labor analgesia.The analgesic effect is significant,reduces the incidence of adverse events during labor,can be safely and effectively applied in clinical practice.This could be suitable for promotion and use in clinical practice.