Minimum effective local anesthetic dose of intrathecal hyperbaric ropivacaine and bupivacaine for cesarean section

作     者：GENG Zhi-yu WANG Dong-xin WU Xin-min 

作者机构：Department of Anesthesiology and Surgical Intensive Care Peking University First Hospital Beijing 100034 China 

出 版 物：《Chinese Medical Journal》 (中华医学杂志（英文版）)

年 卷 期：2011年第124卷第4期

页      面：509-513页

核心收录：

学科分类：090603[农学-临床兽医学] 1007[医学-药学(可授医学、理学学位)] 100704[医学-药物分析学] 09[农学] 0906[农学-兽医学] 10[医学] 

主　　题：anesthesia, obstetric, cesarean section anesthetics local, ropivacaine anesthetic technique,subarachnoid dose-response relationship 

摘      要：Background Intrathecal anesthesia is commonly used for cesarean section. Bupivacaine and ropivacaine have all been used as intrathecal drugs. The minimum effective local anesthetic dose （MLAD） of intrathecal ropivacaine for nonobstetric patients has been reported. However, few data are available on the MLAD of hyperbaric ropivacine for obstetric patients and the relative potency to bupivacaine has not been fully determined. In this study, we sought to determine the MLAD of intrathecal ropivacaine and bupivacaine for elective cesarean section and to define their relative potency *** We enrolled forty parturients undergoing elective cesarean section under combined spinal-epidural anesthesia and randomized them to one of two groups to receive intrathecal 0.5% hyperbaric ropivacaine or *** initial dose was 10 mg, and was increased in increments of 1 mg, using the technique of up-down sequential allocation. Efficacy was accepted if adequate sensory dermatomal anesthesia to pin prick to T7 or higher was attained within 20 minutes after intrathecal injection, and required no supplementary epidural injection for procedure until at least 50 minutes after the intrathecal *** The intrathecal MLAD was 9.45 mg （95%confidence interval （CI）, 8.45-10.56 mg） for ropivacaine and 7.53 mg （95%CI, 7.00-8.10 mg） for bupivacaine. The relative potency ratio was 0.80 （95% Cl, 0.74-0.85） for ropivacaine/bupivacaine when given intrathecally in cesarean *** Ropivacaine is 20% less potent than bupivacaine during intrathecal anesthesia for cesarean delivery.