Patient-controlled epidural analgesia for labor pain: effect on labor, delivery and neonatal outcome of 0.125% bupivacaine vs 0.2% ropivacaine.

The objective was to evaluate the influence of patient-controlled epidural analgesia (PCEA) using low doses of bupivacaine vs. ropivacaine, on labor pain, motor blockade, progression of labor, delivery and neonatal outcome. This randomized double blind study included 565 parturients. All received a 5-mL/h infusion and PCEA (5-mL boluses with a 20-min lockout, maximum volume 20 mL/h) of either 0.125% bupivacaine (n = 313: 165 nulliparous, 148 parous) or 0.2% ropivacaine (n = 252: 113 nulliparous, 139 parous). Pain score, lower limb motor block, sensory levels, local analgesic doses required, hemodynamic parameters, side effects and complications were assessed. Obstetric variables included cervical dilation at epidural insertion, incidence of ruptured membranes and their duration, use of oxytocin, fetal heart rate changes, duration of labor, mode and outcome of delivery, and use of invasive and non-invasive fetal monitoring. Neonatal characteristics included birth weight, Apgar scores, umbilical artery pH, serum bilirubin, hypoglycemia, need for assisted ventilation, sepsis or sepsis study, feeding difficulties and respiratory distress syndrome. Ropivacaine 0.2% was equianalgesic with 0.125% bupivacaine, but produced less motor block (P < 0.0001). There were no significant differences, however, in duration of labor, delivery type or neonatal outcome.