Dose-response study of spinal hyperbaric ropivacaine for cesarean section

Abstract

Abstract:Background: Spinal hyperbaric ropivacaine may produce more predictable and reliable anesthesia than plain ropivacaine for cesarean section. The dose-response relation for spinal hyperbaric ropivacaine is undetermined. This double-blind, randomized, dose-response study determined the ED50 (50% effective dose) and ED95 (95% effective dose) of spinal hyperbaric ropivacaine for cesarean section anesthesia. Methods: Sixty parturients undergoing elective cesarean section delivery with use of combined spinal-epidural anesthesia were enrolled in this study. An epidural catheter was placed at the L1~L2 vertebral interspace, then lumbar puncture was performed at the L3~L4 vertebral interspace, and parturients were randomized to receive spinal hyperbaric ropivacaine in doses of 10.5 mg, 12 mg, 13.5 mg, or 15 mg in equal volumes of 3 ml. Sensory levels (pinprick) were assessed every 2.5 min until a T7 level was achieved and motor changes were assessed by modified Bromage Score. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and no intraoperative epidural supplement was required. ED50 and ED95 were determined with use of a logistic regression model. Results: ED50 (95% confidence interval) of spinal hyperbaric ropivacaine was determined to be 10.37 (5.23~11.59) mg and ED95 (95% confidence interval) to be 15.39 (13.81~23.59) mg. The maximum sensory block levels and the duration of motor block and the rate of hypotension, but not onset of anesthesia, were significantly related to the ropivacaine dose. Conclusion: The ED50 and ED95 of spinal hyperbaric ropivacaine for cesarean delivery under the conditions of this study were 10.37 mg and 15.39 mg, respectively. Ropivacaine is suitable for spinal anesthesia in cesarean delivery.

Update on the clinical utility and practical use of ropivacaine in Chinese patients

“…The efficacy of intrathecal ropivacaine for regional anesthesia is mainly concluded from studies of Chinese patients undergoing cesarean section,39,40 urological surgery,41 or orthopedics surgery 11,42. Doses of ropivacaine used for spinal anesthesia have ranged from 8 to 22.5 mg, and it has been suggested that ropivacaine is less potent than bupivacaine 43–45.…”

Low-dose spinal anaesthesia for Caesarean section to prevent spinal-induced hypotension

“…Chen et al [27] performed a dose-response study of spinal hyperbaric ropivacaine in 60 parturients scheduled for elective Caesarean section. The patients were randomized to four groups and received intrathecally, using a CSE technique, 10.5, 12, 13.5 or 15 mg of hyperbaric ropivacaine following a fluid load with 1000 ml of Ringer's lactate solution.…”

A Comparative Study of Intrathecal Isobaric Ropivacaine with Different Doses of Clonidine in Lower Extremity Surgery

“…No statistically differences between patient demographics and surgery duration were found between the three groups (table1). [4], [5], [6] .…”