硬膜外可乐定预先给药对子宫切除术病人左旋布比卡因硬膜外麻醉与术后镇痛效应的影响

Effect of epidural clonidine pretreatment on the analgesic efficacy of epidural levobupivacaine for hysterectomy and patient-controlled analgesia

目的评价硬膜外不同剂量可乐定预先给药对子宫切除术病人左旋布比卡因硬膜外麻醉及术后硬膜外自控镇痛效果的影响。方法45例ASAⅠ或Ⅱ级子宫切除术病人,随机分为3组(n =15),生理盐水对照组(C0组)、硬膜外预先注射2μg／kg可乐定组(C2组)、硬膜外预先注射4μg／kg可乐定组(C4组)。腰椎2,3间隙硬膜外穿刺、置管,注射可乐定15 min后,以0．5％左旋布比卡因行硬膜外麻醉。术后硬膜外镇痛药液含左旋布比卡因2 mg／ml和舒芬太尼0．4μg／ml。结果全部病人硬膜外麻醉效果满意。3组左旋布比卡因用量、术中补液速率、MAP和HR变化幅度相似;与C0组相比,首次剂量麻醉维持时间和Bromage分级3级持续时间C2组延长,C4组最长;阿托品使用率分别为6．7％(C0组)、20．0％(C2组)、40．0％(C4组),麻黄碱使用率分别为6．7％(C0组)、20．0％(C2组)、26．7％(C4组),组间比较差异有统计学意义(P<0．05);术后24 h镇痛药用量C0组最多,C4组最少; Ramasy分级>2级比例比较,C0组最低,C4组最高;呕吐发生率分别为26．7％(C0组)、20．0％(C2组)、0(C4组),组间两两比较差异均有统计学意义(P<0．05)。结论硬膜外可乐定预先给药可增强左旋布比卡因硬膜外麻醉及术后病人自控镇痛效果并减少药物副作用,但对血压和心率会有一定的抑制作用。

Objective To investigate the effect of epidural clonidine pretreatment on the analgesic efficacy of epidural levobupivacaine for transabdominal hysterectomy and postoperative patient-controlled analgesia （PCA）. Methods Forty-five ASA Ⅰ or Ⅱ patients aged 37-59 yrs weighing 35-72 kg undergoing elective hysterectomy under epidural anesthesia were randorrdy divided into 3 groups （ n = 15 each） ： the patients were pretreated with epidural normal saline （ control group, group Co ） or epidural clonidine 2 （ group Ca ） or 4 μg·kg^-1 （ group C4 ） Epidural anesthesia was performed at L2.3 interspace. The catheter was advanced 3 cm into epidural space cephalad. The correct placement was identified by a test dose of 2% lidocaine 3 ml. Clonidine 2 or 4 μg·kg^-1 or normal saline was administered via epidural catheter, and 15 min later 0.5% levobupivacaine 20 ml was given epidurally. An additional 5 ml was administered if the upper sensory level did not reach T6 . Ephedrine 10 mg was given i.v. if MAP dropped by 10% of the baseline and atropine 0.5 mg was given i.v. if HR was 〈 55 bpm. Postoperative PCEA was started when VAS score 〉 3 （0 = no pain, 10 = worst pain）. A dilute levobupivacaine solution （0.2 % ） containing sufentanil 0.4 μg·ml^- 1 was used for PCEA （ loading dose 5 ml, background infusion 1 ml·h^-1 , bolus dose 2 ml, lock-out interval 10 min） .Results Epidural anesthesia was adequate in all patients with a T6 sensory level. The duration of analgesia and maximal degree of motor block （ Bromage score of 3） after the initial dose of levobupivacaine were shortest in group Co and longest in group C4. The percentage of the patients in whom atropine was used was 6.7% （group Co ）, 20% （group C2 ） and 40% （group C4 ） and ephedrine was used in 6.7% （group C0 ）, 20% （group Ca ） and 26.7% （group C4 ） of patients respectively. The total amount ofanalgesics consumed during the 24 h of PCEA was largest in group Co and smallest in group C4. The percentage of patients with Ramsay score 〉 2 （0 = wide awake, 4= no response to prodding） was highest in group C4 and lowest in group Co. The incidence of vomiting was 26.7% in group Co, 20.0% in group C2 and 0 in group C4 respectively. Conclusion Epidural clonidine pretreatment can potentiate the analgesic efficacy of epidural levobupivacaine for surgery and postoperative PCEA with less side-effects but MAP and HR can be inhibited to some extent.