Fettes P D W, Hocking G, Peterson M K, Luck J F, Wildsmith J A W
University Department of Anaesthesia, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK.
Br J Anaesth. 2005 Jan;94(1):107-11. doi: 10.1093/bja/aei008. Epub 2004 Oct 29.
Preliminary work has shown that ropivacaine provides spinal anaesthesia of shorter duration than bupivacaine, and may be of particular use in the day-case setting. However, there are few data comparing the actions of plain and hyperbaric solutions of this drug.
Forty ASA grade I-II patients undergoing elective perineal surgery under spinal anaesthesia were randomized to receive 3 ml ropivacaine 5 mg ml(-1), either in plain solution or with glucose 50 mg ml(-1). The extent and duration of sensory and motor block, pulse rate, blood pressure, and time to mobilization were recorded.
Two patients (one per group) were withdrawn because of total block failure. There were significant differences in median time to onset of sensory block at T10 (plain 10 min; hyperbaric 5 min; P<0.01), median maximum extent (plain T8; hyperbaric T4; P<0.05), and median duration of sensory block at T10 (plain 25 min; hyperbaric 115 min; P<0.001). However, median times to complete regression of both sensory (270 vs 240 min; P<0.05) and motor (180 vs 120 min; P<0.001) block were longer in the plain group. Patients therefore mobilized sooner in the hyperbaric group (218 [n=16] vs 286 min [n=17]; P<0.01). All the hyperbaric blocks were adequate for surgery, but three patients receiving plain ropivacaine required general anaesthesia.
Addition of glucose 50 mg ml(-1) to ropivacaine 5 mg ml(-1) increases the speed of onset, block reliability, duration of useful block for perineal surgery, and speed of recovery. Plain solutions are less reliable for surgery above a dermatomal level of L1.
初步研究表明，罗哌卡因产生的脊髓麻醉持续时间比布比卡因短，可能特别适用于日间手术。然而，关于该药物普通溶液和重比重溶液作用比较的数据较少。
40例接受脊髓麻醉下择期会阴手术的ASA I-II级患者被随机分为两组，分别接受3ml浓度为5mg/ml的罗哌卡因普通溶液或含50mg/ml葡萄糖的重比重溶液。记录感觉和运动阻滞的范围及持续时间、脉搏率、血压和活动时间。
两名患者（每组一名）因阻滞完全失败而退出。在T10水平，感觉阻滞的中位起效时间有显著差异（普通溶液组为10分钟；重比重溶液组为5分钟；P<0.01），中位最大阻滞范围也有显著差异（普通溶液组为T8；重比重溶液组为T4；P<0.05），T10水平感觉阻滞的中位持续时间同样有显著差异（普通溶液组为25分钟；重比重溶液组为115分钟；P<0.001）。然而，普通溶液组感觉阻滞（270分钟对240分钟；P<0.05）和运动阻滞（180分钟对120分钟；P<0.001）完全消退的中位时间更长。因此，重比重溶液组患者活动更早（218分钟[n = 16]对286分钟[n = 17]；P<0.01）。所有重比重溶液阻滞均足以完成手术，但三名接受普通罗哌卡因的患者需要全身麻醉。
在5mg/ml罗哌卡因中添加50mg/ml葡萄糖可加快起效速度、提高阻滞可靠性、延长会阴手术有效阻滞持续时间并加快恢复速度。对于L1皮节以上的手术，普通溶液的可靠性较低。
