Dose-response study of spinal hyperbaric ropivacaine for cesarean section

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.     

Comparison of 1.5% lidocaine and 0.5% ropivacaine epidural anesthesia combined with propofol general anesthesia guided by bispectral index

Objective： To compare the effects of epidural anesthesia with 1.5% lidocaine and 0.5% ropivacaine on propofol requirements, the time to loss of consciousness （LOC）, effect-site propofol concentrations, and the hemodynamic variables during induction of general anesthesia guided by bispectral index （BIS） were studied. Methods： Forty-five patients were divided into three groups to receive epidurally administered saline （Group S）, 1.5% （w/w） lidocaine （Group L）, or 0,5% （w/w） ropivacaine （Group R） Propofol infusion was started to produce blood concentration of 4 lag/ml. Once the BIS value reached 40-50, endotracheal intubation was facilitated by 0.1 mg/kg vecuronium. Measurements included the time to LOC, effect-site propofol concentrations, total propofol dose, mean arterial blood pressure （MABP）, and heart rate （HR） at different study time points. Results： During induction of anesthesia, both Groups L and R were similar for the time to LOC, effect-site propofol concentrations, total propofol dose, MABP, HR, and BIS. The total doses of propofol administered until 1 min post-intubation were significantly less in patients of Groups R and L compared with Group S. MABP and HR were significantly lower following propofol induction compared with baseline values in the three groups, or MABP was significantly increased following intubation as compared with that prior to intubation in Group S but not in Groups R and L while HR was significantly increased following intubation in the three groups. Conclusion： Epidural anesthesia with 1.5% lidocaine and 0.5% ropivacaine has similar effects on the time to LOC, effect-site propofol concentrations, total propofol dose, and the hemodynamic variables during induction of general anesthesia.     

芬太尼吗啡联合用于罗哌卡因蛛网膜下腔阻滞和术后镇痛

目的随机双盲对照研究比较剖宫产手术中使用芬太尼和吗啡单独或联合进行罗派卡因蛛网蟆下腔阻滞效果差别。方法99例择期在0．75％罗哌卡因7．5mg蛛网膜下腔阻滞行剖宫产手术的产妇随机分配到三组；F组在蛛网膜下腔同时给与芬太尼15^ug，M组给与吗啡0．25mg，FM组给与芬太尼150^ug＋吗啡0．25mg，所有的产妇在手术以后给与病人自控镇痛系统（PCA）进行吗啡术后镇痛。结果各组在术中舒适度、麻黄碱消费量、恶心呕吐、瘙痒和镇静等方面没有显著的差异（p〉0．05）；F组和FM组与M组之间相比取得感觉阻滞效果时间有显著差异（p〈0．05）；F组和M组以及F和FM组之间，吗啡术后镇痛消耗量在4，8，12和24小时有显著的差异（p〈0．01），在2小时点，F组和FM组之间已有显著差异（p〈0．05）。结论与单独使用芬太尼比较，蛛网膜下腔吗啡与芬太尼合用可以提供更加良好的术后镇痛，与单独使用吗啡相比，蛛网膜下腔吗啡与芬太尼合用可以更快的建立阻滞平面；结果表明不同给药途径吗啡单独使用在手术后均能够提供良好的镇痛。