A comparison between low-dose ropivacaine and bupivacaine at equianalgesic concentrations for epidural analgesia during the first stage of labor

The aim of this study was to evaluate the efficacy, onset and duration of analgesia of two equianalgesic epidural doses of ropivacaine and bupivacaine during the first stage of labor. The study included 190 healthy nulliparous parturients who presented spontaneous onset of labor and required epidural analgesia. They were divided randomly to receive epidural analgesia with an initial dose 0.10% ropivacaine or 0.0625% bupivacaine 20 mt both with the addition of 10 mu g of sufentanil. There were no significant differences in onset time, quality of analgesia, maternal hypotension and ability to ambulate. Ropivacaine produced more prolonged analgesia then bupivacaine (89 vs 119 min; P<0.0003). The clinical value of this prolonged analgesia after the first dose needs further evaluation when a continuous infusion technique is used. (C) 2000 Harcourt Publishers Ltd.