The present study was designed to develop a combined spinal epidural (CSE) anesthesia using single segment technique(SST) for cesarean section. We attempted to find the most suitable spinal and epidural local anesthetic doses providing high quality of surgical analgesia and minimal side effects during CSE anesthesia.

40 patients scheduled for elective cesarean section under the CSE technique were randomly divided into four groups. 2.5mg(Group 1), 5mg(Group 2), 7.5mg(Group 3) and 10mg(Group 4) of 0.5% hyperbaric bupivacaine was injected into the subarachnoid space through a 26-gauge long Quincke needle. If the block did not reach the T4 level in 15min., it was extended by fractionated doses of 2% lidocaine with 1:200,000 epinephrine administered through the epidural catheter.

All patients in Group 1, 2 and 3 needed epidural lidocaine, 21.0±0.8 ml(Group 1), 11.1±0.6 ml(Group 2) and 7.4±0.7 ml(Group 3). Anesthesia in Group 4 was mostly due to spinal block. Group 2 and 3 resulted in satisfactory anesthesia with rapid onset, good surgical analgesia and muscle relaxation and minimal side effects. Group 1 provided insufficient muscle relaxation and Group 4 had higher incidence(60%) of maternal hypotension than other groups.

The CSE technique, using 5mg or 7.5mg of subarachnoid bupivacaine and with sufficient epidural lidocaine to reach a T4 level, had the advantages of both spinal and epidural anesthesia with few of the complications of either.