Singelyn F J, Gouverneur J M, Robert A
Department of Anesthesiology, Universisté Catholique de Louvain School of Medecine, St. Luc Hospital, Brussels, Belgium.
Anesth Analg. 1996 Nov;83(5):1046-50. doi: 10.1097/00000539-199611000-00025.
This study assessed the minimum dose of clonidine required to prolong the duration of both anesthesia and analgesia after axillary brachial plexus blockade. Eighty patients scheduled for elective hand surgery were divided into eight groups in a randomized, double-blind fashion. An axillary brachial plexus block was performed with 40 mL 1% mepivacaine plus 1:200,000 epinephrine. The control group received no clonidine. In the other groups, increasing doses of clonidine (0.1, 0.2, 0.3, 0.4, 0.5, 1, and 1.5 micrograms/kg) were added to the local anesthetic solution. Onset time, duration of anesthesia and analgesia, postoperative pain score, intake of analgesics, and adverse effects were recorded. The eight groups were comparable in terms of onset time, postoperative pain score, and analgesic requirement. The minimum dose of clonidine required to significantly prolong the duration of analgesia and anesthesia was, respectively, 0.1 and 0.5 microgram/kg. No side effects (sedation, drowsiness, bradycardia, arterial hypotension) were reported. We conclude that the dose of clonidine required to prolong significantly the duration of both anesthesia and analgesia after axillary brachial plexus blockade is 0.5 microgram/kg and that, at this dose, clonidine may be used without important reported side effects even in outpatients.
本研究评估了在腋路臂丛神经阻滞后延长麻醉和镇痛持续时间所需可乐定的最小剂量。80例择期手部手术患者被随机、双盲分为八组。采用40 mL 1%甲哌卡因加1:200,000肾上腺素进行腋路臂丛神经阻滞。对照组未给予可乐定。在其他组中，向局部麻醉溶液中加入递增剂量的可乐定（0.1、0.2、0.3、0.4、0.5、1和1.5微克/千克）。记录起效时间、麻醉和镇痛持续时间、术后疼痛评分、镇痛药摄入量及不良反应。八组在起效时间、术后疼痛评分和镇痛需求方面具有可比性。显著延长镇痛和麻醉持续时间所需可乐定的最小剂量分别为0.1和0.5微克/千克。未报告副作用（镇静、嗜睡、心动过缓、动脉低血压）。我们得出结论，腋路臂丛神经阻滞后显著延长麻醉和镇痛持续时间所需可乐定的剂量为0.5微克/千克，并且在此剂量下，即使在门诊患者中使用可乐定也未报告有重要的副作用。
