652: the Effect of Epidural Volume Extension Technique on Minimum Effective Dose of Ropivacaine in Early Labor Analgesia

ackground and Aims: The technique of epidural volume exension (EVE) involves the injection of saline into the epidural pace soon after the intrathecal injection when a combined spinalpidural anesthesia is performed. The benefit of EVE should be a eduction in local anesthetic request. This study aimed at comparng the median effective dose (ED50) of ropivacaine with and ithout EVE in spontaneous labouring women.