Department of Anesthesia, Montreal General Hospital, McGill University, Montreal, Quebec, Canada.
Reg Anesth Pain Med. 2013 May-Jun;38(3):206-11. doi: 10.1097/AAP.0b013e318287fe53.
This prospective, randomized, observer-blinded study compared 3 combinations of volume and concentration using the same total dose of lidocaine for ultrasound-guided infraclavicular block.
Ninety patients were randomized to 1 of 3 combinations of volume and concentration for lidocaine: (1) 52.5 mL of lidocaine 1%, (2) 35 mL of lidocaine 1.5%, and (3) 26.25 mL of lidocaine 2%. In all 3 groups, the total dose administered (525 mg) was the same. In addition, epinephrine 5 fg/mL was used in all subjects. The main outcome variable was onset time. The performance time, number of needle passes, block-related pain scores, success rate (surgical anesthesia), and the incidence of vascular puncture and paresthesia were also recorded. The total anesthesia-related time was defined as the sum of the performance and onset times.
The onset times, which were 18.8 ± 5.6 minutes (95% confidence interval [CI], 16.4-21.1 minutes), 20.7 ± 7.0 minutes (95% CI, 18.0-23.5 minutes), and 21.7 ± 6.0 minutes (95% CI, 19.1-24.2 minutes) for the 1%, 1.5%, and 2% groups, respectively, were not statistically different.Furthermore, the performance times (4.4-4.7 minutes), total anesthesia-related times (23.7-26.3 minutes), and rates of surgical anesthesia (90.0%-96.7%) were comparable among the 3 groups. The number of needle passes and procedural discomfort, as well as the incidence of paresthesia and vascular puncture, were also similar. There were minor differences in the patterns of block for individual nerves. In terms of sensory block, compared with the 2% group, more patients in the 1.5% group displayed a complete block of the ulnar and radial nerves at 10 and 20 minutes, respectively. In terms of motor block, the 2% group yielded the lowest of rate of complete block of the musculocutaneous nerve from 15 minutes onward.
Using an identical dose (525 mg) of adrenalized lidocaine for ultrasound-guided infraclavicular block, we found no differences in onset time among 3 commonly used concentrations (1%, 1.5%, and 2%). Further studies are required to determine the optimal combination of volume and concentration of lidocaine for other ultrasound-guided approaches to the brachial plexus.
本前瞻性、随机、观察者盲法研究比较了在相同利多卡因总量下，3 种不同容量和浓度组合用于超声引导锁骨下阻滞的效果。
90 名患者随机分为 3 组，接受 1%利多卡因 52.5ml（组 1）、1.5%利多卡因 35ml（组 2）和 2%利多卡因 26.25ml（组 3）。所有 3 组的总剂量（525mg）相同。所有患者均使用肾上腺素 5fg/ml。主要观察指标为起效时间。还记录操作时间、穿刺针次数、阻滞相关疼痛评分、成功率（手术麻醉）、血管穿刺和感觉异常的发生率。总麻醉相关时间定义为操作时间和起效时间之和。
3 组的起效时间分别为 18.8±5.6 分钟（95%可信区间[CI]，16.4-21.1 分钟）、20.7±7.0 分钟（95%CI，18.0-23.5 分钟）和 21.7±6.0 分钟（95%CI，19.1-24.2 分钟），差异无统计学意义。进一步比较，3 组操作时间（4.4-4.7 分钟）、总麻醉相关时间（23.7-26.3 分钟）和手术麻醉成功率（90.0%-96.7%）相当。穿刺针次数和操作不适程度、感觉异常和血管穿刺发生率也相似。个别神经的阻滞模式存在细微差异。在感觉阻滞方面，与 2%组相比，1.5%组在 10 分钟和 20 分钟时尺神经和桡神经完全阻滞的患者更多；在运动阻滞方面，2%组从 15 分钟开始，肌皮神经完全阻滞率最低。
在超声引导锁骨下阻滞中，使用相同剂量（525mg）的含肾上腺素利多卡因时，3 种常用浓度（1%、1.5%和 2%）的起效时间无差异。需要进一步研究确定其他超声引导臂丛神经阻滞方法中利多卡因容量和浓度的最佳组合。
