An epidural initial dose is unnecessary in combined spinal epidural anesthesia for Caesarean section

Combined spinal epidural anesthesia is widely used for Caesarean section. Bolus administration of an epidural initial dose introduces the risk of drug flux from the epidural space to the subarachnoid space, and the volume effect of the initial dose may cause epidural top-up and extension of subarachnoid blockade. These problems may be avoided if the initial dose is not administered. This study investigated whether epidural continuous infusion without an initial dose (continuous group) can decrease postoperative pain as well as an epidural continuous infusion with an initial dose (initial dose group). Sixty-one patients undergoing elective Caesarean section were randomly assigned to the initial dose group or the continuous group. Twenty patients undergoing emergency Caesarean section with spinal anesthesia (spinal group) were also investigated to confirm that epidural block is effective for postoperative pain. Data in this study were obtained retrospectively from each patient's records. Between the initial dose group and the continuous group, there was no significant difference in the number of times flurbiprofen or pentazocine were used for postoperative pain relief. However, the number of times that pentazocine was used was significantly higher in the spinal group than in other groups. This finding suggests that an epidural initial dose is unnecessary for postoperative pain relief in combined spinal epidural anesthesia for Caesarean section.