Reinhart D J, Wang W, Stagg K S, Walker K G, Bailey P L, Walker E B, Zaugg S E
Department of Anesthesiology, University of Utah, Salt Lake City, USA.
Anesth Analg. 1996 Oct;83(4):760-5. doi: 10.1097/00000539-199610000-00018.
Postoperative analgesia may be prolonged by the addition of clonidine to local anesthetic solutions used for regional anesthesia. The purpose of this study was to test this hypothesis in a clinical trial of patients undergoing podiatric surgery. The study design was prospective, double-blinded, and randomized. Ninety ASA physical status I or II patients scheduled for bunionectomy or hammer toe repair were randomized to receive ankle or metatarsal blocks with plain 1.73% lidocaine (Group L), 1.73% lidocaine with 10 micrograms/mL of clonidine added (Group C10), or 1.73% lidocaine with 20 micrograms/mL clonidine (Group C20). Time from the performance of the block to 1) loss of sensation to pinprick, 2) return of sensation to pinprick, 3) onset of postsurgical pain, and 4) time of first oral pain medication intake were recorded. Beginning at 1 h after the completion of the block, visual analog scale (VAS) and verbal pain scores were recorded every 30 min. Additional postoperative oral pain medication required in the first 9 h after the block was also recorded. Analysis of variance (ANOVA) was used to analyze intergroup differences in the VAS and verbal pain scores, the time to first reported pain, the time to first oral pain medication, and the total amount of oral pain medications required. Repeated-measures ANOVA was used to analyze the VAS and verbal pain scores overall and integrated assessment of pain scores and rescue medication was per-formed. Adverse events were also recorded for each group. There were no differences among the three groups with regard to overall VAS pain scores although Group C10 had significantly better verbal pain scores after the first 3 h (P < 0.05). There was also no difference in time to loss or return of pinprick sensation. Group C10 had a longer time to first reported pain (P < 0.01), a longer time to first oral pain medication (P < 0.01), a lower average total dose of oral pain medication required (P < 0.05), and a lower integrated assessment of pain and medication (P < 0.01) than Group L. More patients in Group C10 reported no pain postoperatively (P < 0.01) and no pain medication taken (P < 0.01) than Group L. Group C20 results suggested no statistically significant improvement over plain lidocaine. One patient in Group C20 experienced significant hypotension postoperatively. pH determinations and chemical analysis by capillary electrophoresis showed no significant change in composition of the solutions when clonidine was mixed with lidocaine and stored at 4 degrees C for 1 wk. Compared to 1.73% lidocaine, combining clonidine (10 micrograms/mL) with lidocaine for local anesthetic block for foot surgery significantly increases the duration and quality of postoperative analgesia.
在用于区域麻醉的局部麻醉溶液中添加可乐定，可能会延长术后镇痛时间。本研究的目的是在一项针对接受足科手术患者的临床试验中验证这一假设。该研究设计为前瞻性、双盲和随机对照试验。90例计划行拇囊炎切除术或槌状趾修复术的美国麻醉医师协会（ASA）身体状况分级为I或II级的患者，被随机分为三组，分别接受单纯1.73%利多卡因的踝关节或跖骨阻滞（L组）、添加了10微克/毫升可乐定的1.73%利多卡因（C10组）或添加了20微克/毫升可乐定的1.73%利多卡因（C20组）。记录从实施阻滞到以下情况的时间：1）针刺感觉消失；2）针刺感觉恢复；3）术后疼痛开始；4）首次口服止痛药物的时间。在阻滞完成后1小时开始，每30分钟记录一次视觉模拟评分（VAS）和语言疼痛评分。还记录了阻滞完成后最初9小时内额外需要的术后口服止痛药物。采用方差分析（ANOVA）分析VAS和语言疼痛评分、首次报告疼痛的时间、首次口服止痛药物的时间以及所需口服止痛药物总量的组间差异。采用重复测量方差分析来分析总体VAS和语言疼痛评分，并对疼痛评分和急救药物进行综合评估。还记录了每组的不良事件。三组的总体VAS疼痛评分无差异，尽管C10组在最初3小时后的语言疼痛评分明显更好（P<0.05）。针刺感觉消失或恢复的时间也无差异。与L组相比，C10组首次报告疼痛的时间更长（P<0.01），首次口服止痛药物的时间更长（P<0.01），所需口服止痛药物的平均总量更低（P<0.05），疼痛和药物的综合评估更低（P<0.01）。与L组相比，C10组更多患者术后报告无疼痛（P<0.01）且未服用止痛药物（P<0.01）。C20组的结果表明，与单纯利多卡因相比，无统计学上的显著改善。C20组有1例患者术后出现明显低血压。pH测定和毛细管电泳化学分析显示，可乐定与利多卡因混合并在4℃下储存1周后，溶液成分无显著变化。与1.73%利多卡因相比，将可乐定（10微克/毫升）与利多卡因联合用于足部手术的局部麻醉阻滞，可显著延长术后镇痛时间并提高镇痛质量。
