剖宫产术患者左旋布比卡因蛛网膜下腔阻滞的量效关系

目的 确定剖宫产术患者左旋布比卡因蛛网膜下腔阻滞的量效关系.方法 择期剖宫产术患者印例,年龄25～35岁,体重60～90 kg,ASA Ⅰ或Ⅱ级,随机分为4组(n=15),于L3,4蛛网膜下腔穿刺成功后,分别注射左旋布比卡因7.5 mg(L1组)、10 mg(L2组)、12.5 mg(L3组)和15 mg(L4组),均用5%葡萄糖稀释至3 ml,注药时间30 s.采用视觉模拟评分法(VAS)评价切皮即刻患者疼痛程度,0分为无痛,10分为剧痛.VAS评分=0分为镇痛有效;VAS评分≥1分为镇痛无效,硬膜外追加1%利多卡因5～10 ml.采用Probit法计算50%和95%患者镇痛有效的左旋布比卡因剂量(ED50和ED95)及其95%可信区间.结果 左旋布比卡因的ED50及其95%可信区间为9.0(7.8～9.9)mg,ED95及其95%可信区间为13.2(11.6～17.6)mg.结论 剖宫产术患者左旋布比卡因蛛网膜下腔阻滞的ED50和ED95分别为9.0、13.2 mg.

Dose-response relationship of levobupivacaine for spinal anesthesia in patients undergoing cesarean section

Objective To investigate the dose-respeuse relationship of levobupivacaine for spinal anesthesia in patients undergoing cesarean section.Methods Sixty ASA Ⅰ or Ⅱ patients aged 25-35 yr weighing 60-90 kg scheduled for elective cesarean section under spinal anesthesia were enrolled in this study.Spinal puncture was performed at the L3,4 interspace.A 25 G spinal needle was inserted into the subarachnoid space cephalad.The patients were randomized to receive levobupivacaine 7.5 mg (group L1 ),10 mg (group L2),12.5 mg (group L3) or 15 mg (group L4) diluted to 3 ml with 5% glucose over 30 s (n = 15 each).The degree of pain was evaluated at the time of skin incision using visual analogue scales (VAS) (0 = no pain and 10 = worse pain ever).Effective analgesia was defined as VAS = 0.Spinal analgesia was inadequate when VAS≥1 and then 1% lidocaine 5-10 ml was given epidurally.The doses of levobupivacaine for effective analgesia in 50% and 95% of patients ( ED50 and ED95 ) and 95 % confidence interval were calculated by Probit method.Results The ED50 of levobupivacaine was 9.0 mg (95% confidence interval 7.8-9.9 mg) and ED95 13.2 mg (95% confidence interval 11.6-17.6 mg) for spinal anesthesia.Conclusion The ED50 and ED95 of levobupivacaine for spinal anesthesia in patients undergoing cesarean section are 9.0 mg and 13.2 mg respectively.