三种不同局麻药腰麻最大运动阻滞效应的比较

目的 采用序贯试验评估罗哌卡因、左旋布比卡因和布比卡因鞘内注射后达到Bromage 3级的半数有效剂量(ED50),比较三种局麻药腰麻的运动阻滞效应.方法 腰-硬联合麻醉(CSEA)下择期行妇科手术患者99例,随机分为罗哌卡因组、左旋布比卡因组和布比卡因组,分别鞘内注射0.5%等比重罗哌卡因、左旋布比卡因或布比卡因,起始剂量均为7 mg,剂量变化梯度为1mg,鞘内注药后25 min内双下肢改良Bromage达到3级为有效.结果 罗哌卡因组腰麻产生最大运动阻滞的ED50 为9.62 mg,95%可信区间(CI)为9.16～10.09 mg;左旋布比卡因组的ED50为9.55mg,95% CI为9.01～10.11 mg;布比卡因组的ED50为6.08 mg,95% CI为5.39～6.80 mg.罗哌卡因最大运动阻滞相对效价比是布比卡因的0.63倍(95% CI 0.56～O.73).结论 罗哌卡因和左旋布比卡因腰麻的运动阻滞效应明显低于布比卡因,而罗哌卡因与左旋布比卡因无明显差异.     

剖宫产术患者蛛网膜下腔注射不同等比重局麻药的药效学

目的 探讨剖宫产术患者蛛网膜下腔注射不同等比重局麻药的药效学.方法 拟在脊椎-硬膜外联合阻滞下行剖宫产术患者96例,孕37～41周,ASA分级Ⅰ或Ⅱ级,体重50～85kg,随机分为3组(n=32):布比卡因组、左旋布比卡因组和罗哌卡因组分别于蛛网膜下腔注射等比重0.5%布比卡因、等比重0.5%左旋布比卡因和等比重0.5%罗哌卡因.采用序贯法进行试验,初始剂量为9 mg,相邻剂量比为0.9,麻醉有效,则下一例患者采用低一级剂量;麻醉无效,则下一例患者采用高一级剂量.麻醉有效的标准:注射局麻药后15 min内感觉阻滞平面达到T7或以上、术中无牵拉痛、注射局麻药后45 min内硬膜外不需要追加局麻药.计算3种局麻药麻醉的半数有效剂量(ED50)和95%有效剂量(ED95)及其95%可信区间(95%CI).结果 布比卡因麻醉有效的ED50(95%CI)、ED95(95%CI)分别为6.15(5.48～6.68)mg、7.62(6.91～11.82)mg;左旋布比卡因麻醉有效的ED50(95%CI)、ED95(95%CI)分别为8.06(7.46～8.62)mg、9.59(8.86～13.42)mg;罗哌卡因麻醉有效的ED50(95%CI)、ED95(95%CI)分别为10.55(9.73～11.49)mg、12.80(11.66～21.42)mg.布比卡因、左旋布比卡因和罗哌卡因的效价比为1.00:0.76:0.58.结论 剖宫产术患者蛛网膜下腔注射等比重布比卡因、左旋布比卡因和罗哌卡因麻醉有效的效价比为1.00∶0.76∶0.58.     

鞘内注射罗哌卡因、左旋布比卡因和布比卡因后运动阻滞效能的比较

目的测定罗哌卡因、左旋布比卡因和布比卡因鞘内注射后运动阻滞的半数有效量（ED50）及其运动阻滞的相对效能。方法104例在腰麻、硬膜外联合麻醉下行择期剖宫产的产妇随机分为3组，分别鞘内注射0．5％（质量／体积）的罗哌卡因、左旋布比卡因和布比卡因，起始剂量是4mg，试验递增剂量为1mg.有效的定义是：鞘内注药5分钟内任一下肢出现运动阻滞（改良的Bromage评分和臀部运动功能评分）。结果鞘内注射罗哌卡因运动阻滞的ED50值为5．79mg（95％CI：4．62～6．96）；左旋布比卡因的ED50为4．83mg（95％CI：4．35～5．32）；布比卡因的ED50为3．44mg（95％CI：2．55～4．34）（P〈0．0007）。运动阻滞效能的相对比例：罗哌卡因／布比卡因为0．59（95％CI：0．42—0．82）；罗哌卡因／左旋布比卡因为0．83（95％CI：0．64～1．09）；左旋布比卡因／布比卡因为0．71（95％CI：0．51～0．98）。结论3种酰胺类局麻药鞘内注射后运动阻滞效能由低到高分别是：罗哌卡因、左旋布比卡因和布比卡因。     

妇科手术患者蛛网膜下腔注射布比卡因与左旋布比卡因运动阻滞效应的比较

目的 比较妇科手术患者蛛网膜下腔注射布比卡因与左旋布比卡因运动阻滞的的效应.方法 拟在脊椎-硬膜外联合麻醉下行妇科手术的患者60例,ASA Ⅰ或Ⅱ级,年龄20～60岁,身高155～170 cm,体重指数<30 kg/m2,随机分为2组(n=30),布比卡因组(B组):蛛网膜下腔注射等比重0.5%布比卡因;左旋布比卡因组(L组):蛛网膜下腔注射等比重0.5%左旋布比卡因.采用序贯法进行试验,每组第1例患者局麻药剂量均为5 mg,剂量变化梯度为1 mg.运动阻滞有效定义为蛛网膜下腔注药结束后20 min内双下肢改良Bromage评分均达到3分.若上1例有效,则下1例采用低一级剂量;若无效,则下1例采用高一级剂量.采用概率单位回归法计算两药运动阻滞的半数有效剂量(ED50)及其95%可信区间(95%CI).结果 布比卡因运动阻滞的ED50及其95%CI为6.04(5.30～6.93)mg,左旋布比卡因运动阻滞的ED50及其95%CI为9.55(8.62～10.97)mg,布比卡因运动阻滞的ED50低于左旋布比卡因(P<0.01);左旋布比卡因与布比卡因运动阻滞的效价比及其95%CI为0.63(0.52～0.75).结论 左旋布比卡因蛛网膜下腔麻醉时运动阻滞的效应低于布比卡因.     

不同剂量等比重罗哌卡因对老年患者腰麻阻滞平面的影响

目的 观察不同剂量0.5%等比重罗哌卡因用于老年患者腰麻对阻滞平面的影响.方法 65岁以上经尿道前列腺电切术患者160例随机分为四组,每组40例.A、B、C、D四组蛛网膜下腔分别注入0.5%等比重罗哌卡因7.5、10、12.5、15 mg.用针刺法测定感觉阻滞平面,用改良Bromage法评估下肢运动阻滞程度,比较四组患者的感觉和运动阻滞效果.结果 最高阻滞平面:D组＞C组＞B组＞A组.D组阻滞平面固定时间显著长于A组(P＜0.05).A、B组感觉阻滞消退时间短于C、D组(P＜0.01).结论 0.5%等比重罗哌卡因腰麻时局麻药剂量越大阻滞平面越高.老年患者经尿道前列腺电切术选择0.5%罗哌卡因10～12.5 mg为宜.     

蛛网膜下腔注射罗哌卡因与布比卡因运动神经阻滞效力的比较

目的 比较蛛网膜下腔注射罗哌卡因与布比卡因的运动神经阻滞效力.方法 择期脊椎.硬膜外麻醉下拟行泌尿外科腔镜手术患者60例,年龄18～64岁,体重46～75 kg,ASA分级Ⅰ或Ⅱ级,采用随机数字表法,将患者随机分为2组(n=30):0.5%罗哌卡因组和0.5%布比卡因组.按照序贯法进行试验,阻滞有效,下一例患者采用低一级剂量,阻滞无效,下一例患者采用高一级剂量,初始剂量均为4 mg,剂量梯度1 mg,阻滞有效的标准:蛛网膜下腔给药后5或10 min时任一下肢的任一种运动神经阻滞评分>0分.采用序贯法计算蛛网膜下腔注射罗哌卡因或布比卡因运动神经阻滞的半数有效剂量(ED50)及其95%置信区间.结果 患者蛛网膜下腔注射罗哌卡因和布比卡因运动神经阻滞的ED50及其95%置信区间分别为6.68(6.27～7.13)mg和4.07(3.56～4.47)mg,效力比为O.61.结论 患者蛛网膜下腔注射罗哌卡因运动神经阻滞效力低于布比卡因.

Abstract：

Objective To determine the median effective doae (ED50) for motor block after intrathecal ropivacaine and bupivacaine. Methods Sixty ASA Ⅰ or Ⅱ patients, aged 18-64, weighing 46-75 kg, undergoing elective urological surgery under combined spinal-epidural anesthesia, were randomized into 2 groups ( n = 30each) receiving intrathecal 0.5% ropivacaine and 0.5% bupivacaine respectively. The ED50 was determined by up-down sequential allocation. The initial dose was 4 mg. Each time the dose increased/decreased by 1 mg. Efficacy was determined by the occurrence of any motor block in either lower extremity (modified Bromage scale > 0)within 5 or 10 min after the spinal injection. Results The intrathecal ED50 for motor block was 6.68 mg for ropivacaine (95% confidence interval 6.27-7.13 mg) and 4.07 mg for bupivacaine (95% confidence interval 3.56-4.47mg) . The relative motor blocking potency ratio was ropivacaine/bupivacaine 0.61. Conclusion The potency of intrathecal ropivacaine is lower than that of bupivacaine for motor block.     

左旋布比卡因与布比卡因腰麻在经尿道前列腺电切术中的比较

目的比较左旋布比卡因与布比卡因腰麻用于老年患者经尿道前列腺电切术的麻醉效果和并发症。方法选择择期行经尿道前列腺电切术的老年患者40例,年龄65～91岁,ASAⅠ～Ⅲ级,随机分为两组:L组,20例,0.5%左旋布比卡因1.5ml,B组,20例,0.5%布比卡因1.5ml,均行单次蛛网膜下腔注射。观察并记录感觉阻滞最高平面、到达感觉阻滞最高平面时间、感觉消退至L5的时间,运动神经阻滞时间、围术期血压与心率变化以及恶心、呕吐、寒战、皮肤瘙痒、呼吸抑制等副作用。结果所有患者麻醉镇痛完善。B组感觉阻滞和运动阻滞达到最高平面的时间明显短于L组(P0.05)。B组给药后10分钟到30分钟的平均动脉压显著低于L组(P0.05)。B组低血压和恶心的发生率显著高于L组(P0.05)。结论左旋布比卡因能满足老年患者TURP的麻醉要求,且血流动力学更稳定,副作用明显减少,更适合老年人的椎管内麻醉。     

左旋布比卡因和罗哌卡因对周围神经的毒性作用及其临床意义

神经损伤为区域神经阻滞的常见并发症,尽管新型酰胺类长效局麻药左旋布比卡因、罗哌卡因的应用增多,布比卡因逐渐减少,但目前尚无充分证据表明此类并发症发生率下降.因而此文将按下述纲领进行阐述:①左旋布比卡因和罗哌卡因与暂时性神经病学综合征(transient neurological syndrome,TNs);②左旋布比卡因和罗哌卡因与马尾神经综合征(Cauda equinea syndrome,CES);③左旋布比卡因和罗哌卡因与周围神经毒性损伤;④预先存在神经病理学改变时左旋布比卡因和罗哌卡因与周围神经毒性损伤;⑤左旋布比卡因和罗哌卡因与肌肉毒性损伤.以供临床麻醉处理及疼痛治疗参考.     

等剂量罗哌卡因、左布比卡因腰麻应用于剖宫产术中的比较

目的比较0.75%罗哌卡因和0.75%左布比卡因对剖宫产手术腰麻的临床效果。方法 160例ASA1～2级择期剖宫产手术患者随机分为0.75%罗哌卡因（R）组和0.75%左布比卡因（L）组。采用25G腰麻穿刺针,于L3～4间隙穿刺。监测两组感觉运动阻滞情况、麻醉效果及不良反应情况。结果 R组最大阻滞时间、最大运动阻滞时间均高于L组;而运动恢复时间,R组低于L组,两组比较差异有统计学意义（P〈0.05）。结论等剂量罗哌卡因和左旋布比卡因腰麻麻醉效果和不良反应差异无统计学意义,左旋布比卡因运动神经阻滞比罗哌卡因更完全,罗哌卡因则具有运动神经阻滞起效慢而恢复较快的特点。     

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.     

A comparison of duration of analgesia of intrathecal 2.5 mg of bupivacaine, ropivacaine, and levobupivacaine in combined spinal epidural analgesia for patients in labor

We assessed the duration of labor analgesia rendered by intrathecal (IT) local anesthetics as the sole drugs. In this randomized, controlled, and double-blinded study, labor analgesia was induced using combined spinal-epidural technique in 60 ASA physical status I nulliparous parturients with IT bupivacaine 2.5 mg (group B), ropivacaine 2.5 mg (group R), or levobupivacaine 2.5 mg (group L). Pain scores (0-100 visual analog scale) and blood pressure were recorded pre-block and for the first 30 min post-block. The degree of motor block and the highest sensory block were also monitored. The duration of analgesia (our primary outcome) was the longest in group B but was similar between groups R and L (mean +/- SE, 76.3 +/- 5.9 min versus 52.6 +/- 4.0 min and 51.5 +/- 3.4 min, respectively, P < 0.05). Group B had the most frequent incidence of lower limb motor block but there was no difference between groups R and L (5 of 20 parturients versus 2 of 20 and 0 of 20, respectively, P < 0.05). The profile of the other side effects was indistinguishable between the groups. With the current regimen, IT bupivacaine produced the longest duration of labor analgesia. IMPLICATIONS: Intrathecal 2.5 mg bupivacaine significantly prolongs the duration of analgesia in laboring patients compared with ropivacaine or levobupivacaine. This suggests that, at clinically relevant doses, bupivacaine may have greater potency.     

Minimum local analgesic doses of ropivacaine, levobupivacaine, and bupivacaine for intrathecal labor analgesia

BACKGROUND: Doses for intrathecal opioid-local anesthetic mixtures have been arbitrarily chosen. The aim of this study was to compare the analgesic efficacies of intrathecal ropivacaine, levobupivacaine, and bupivacaine for labor analgesia and to determine the analgesic potency ratios for these three drugs. For this purpose, the authors used the up-down sequential allocation model, which estimates the minimum local analgesic dose for intrathecal local anesthetic. METHODS: Ninety-seven nulliparous term parturients in spontaneous labor, requesting combined spinal-epidural analgesia, were randomly allocated to one of three groups to receive 0.25% spinal ropivacaine, levobupivacaine, or bupivacaine. The initial dose of the local anesthetic drug was chosen to be 2.5 mg, and the testing interval was set at 0.25 mg. The subsequent doses were determined by the response of the previous parturient. Efficacy was accepted if the visual analog pain score decreased to 10 mm or less on a 100-mm scale within 30 min. The minimum local analgesic dose was calculated using the method of Dixon and Massey. RESULTS: The intrathecal minimum local analgesic dose was 3.64 mg (95% confidence interval, 3.33-3.96 mg) for ropivacaine, 2.94 (2.73-3.16) mg for levobupivacaine, and 2.37 (2.17-2.58) mg for bupivacaine. The relative analgesic potency ratios were 0.65 (0.56-0.76) for ropivacaine:bupivacaine, 0.80 (0.70-0.92) for ropivacaine:levobupivacaine, and 0.81 (0.69-0.94) for levobupivacaine:bupivacaine. There were significant trends (P levobupivacaine > ropivacaine.     

Minimum Local Analgesic Doses of Ropivacaine, Levobupivacaine, and Bupivacaine for Intrathecal Labor Analgesia

Background: Doses for intrathecal opioid-local anesthetic mixtures have been arbitrarily chosen. The aim of this study was to compare the analgesic efficacies of intrathecal ropivacaine, levobupivacaine, and bupivacaine for labor analgesia and to determine the analgesic potency ratios for these three drugs. For this purpose, the authors used the up-down sequential allocation model, which estimates the minimum local analgesic dose for intrathecal local anesthetic.

Methods: Ninety-seven nulliparous term parturients in spontaneous labor, requesting combined spinal-epidural analgesia, were randomly allocated to one of three groups to receive 0.25% spinal ropivacaine, levobupivacaine, or bupivacaine. The initial dose of the local anesthetic drug was chosen to be 2.5 mg, and the testing interval was set at 0.25 mg. The subsequent doses were determined by the response of the previous parturient. Efficacy was accepted if the visual analog pain score decreased to 10 mm or less on a 100-mm scale within 30 min. The minimum local analgesic dose was calculated using the method of Dixon and Massey.

Results: The intrathecal minimum local analgesic dose was 3.64 mg (95% confidence interval, 3.33-3.96 mg) for ropivacaine, 2.94 (2.73-3.16) mg for levobupivacaine, and 2.37 (2.17-2.58) mg for bupivacaine. The relative analgesic potency ratios were 0.65 (0.56-0.76) for ropivacaine:bupivacaine, 0.80 (0.70-0.92) for ropivacaine:levobupivacaine, and 0.81 (0.69-0.94) for levobupivacaine:bupivacaine. There were significant trends (P <= 0.021) for greater motor block with bupivacaine and levobupivacaine.     

Effect of sufentanil on minimum local analgesic concentrations of epidural bupivacaine, ropivacaine and levobupivacaine in nullipara in early labour

BACKGROUND: The aim was to assess the effect of epidural sufentanil on relative analgesic potencies of epidural bupivacaine, ropivacaine and levobupivacaine by determining the minimum local analgesic concentrations during labour. METHODS: In a randomised, double-blind study, 171 parturients were allocated to one of six groups receiving a 10-mL bolus of bupivacaine, ropivacaine or levobupivacaine alone or with sufentanil 0.75 microg/mL. The concentration of local anaesthetic was determined by the response of the previous parturient using up-down sequential allocation starting at a concentration of 0.13% wt/vol with a testing interval of 0.01%. Effective analgesia was defined as a visual analogue pain score < or = 15/100 mm within 30 min and lasting for 30 min. Median effective concentrations were estimated and two-sided P < 0.05 was significant. RESULTS: Local anaesthetic concentration, use of sufentanil and local anaesthetic drug were independent significant predictors of effective and ineffective analgesia. Bupivacaine was significantly more potent than levobupivacaine and ropivacaine. The relative potency ratios without sufentanil of 0.77:0.83:1.00 were reduced to 0.36:0.38:1.00 by the addition of sufentanil. The major factor influencing local anaesthetic requirements was the addition of sufentanil, which reduced overall requirements by a factor of 4.2 (95% CI 3.6-4.8); this effect was proportionately more enhanced for bupivacaine. CONCLUSIONS: Local anaesthetic requirements for bupivacaine, levobupivacaine and ropivacaine follow an analgesic potency hierarchy. Any potency differences are small when compared to the effect of sufentanil, which resulted in a four-fold reduction in local anaesthetic requirements. Sufentanil may also enhance the potency differences between bupivacaine and the two S-enantiomer agents.     

Determination of the full dose-response relation of intrathecal bupivacaine, levobupivacaine, and ropivacaine, combined with sufentanil, for labor analgesia

BACKGROUND: Ropivacaine and levobupivacaine are local anesthetics that produce less motor block and greater sensory-motor separation when compared with equal milligram doses of bupivacaine. Although minimum local analgesic concentration studies suggested that they are less potent than bupivacaine, full dose-response studies have not been performed. The current trial describes the dose-response relation of levobupivacaine, ropivacaine, and bupivacaine, combined with sufentanil, when used for intrathecal labor analgesia. METHODS: Four hundred fifty term parturients in active labor were included in this double-blind, randomized trial. Combined spinal-epidural anesthesia was performed, and ropivacaine, levobupivacaine, or bupivacaine was intrathecally administered in a dose of 1.0, 1.5, 2.0, 2.5, 3.0, or 3.5 mg, always combined with 1.5 microg sufentanil. Patients were considered responders to spinal analgesia if the visual analog scale score for pain was less than 25 mm within 15 min and the visual analog scale score remained less than 25 mm for 45 min. Patient demographics, obstetric data, maternal side effects, and fetal and neonatal well-being were noted. Group-specific dose-response curves were constructed using a probit regression model. RESULTS: The ED95 of bupivacaine was 3.3 mg (95% confidence interval, 2.9-4.1). The ED95s of ropivacaine and levobupivacaine were 4.8 mg (95% confidence interval, 4.0-6.7) and 5.0 mg (95% confidence interval, 4.1-7.0), respectively. Racemic bupivacaine was significantly more potent than ropivacaine (P=0.0027) and levobupivacaine (P=0.0006). Ropivacaine and levobupivacaine were of similar potency (P=0.91). CONCLUSIONS: This full dose-response study suggests that ropivacaine and levobupivacaine are of similar potency, whereas bupivacaine is more potent than both other drugs.     

A comparison of the electrocardiographic cardiotoxic effects of racemic bupivacaine, levobupivacaine, and ropivacaine in anesthetized swine

We sought, in this observer-blinded study, to determine the lethal dose for each of the local anesthetics levobupivacaine (L), racemic bupivacaine (B), and ropivacaine (R), and to compare their respective effects on the QRS interval of the precordial electrocardiograph after intracoronary injection. Anesthetized swine were instrumented with a left anterior descending artery coronary angiography catheter and injected with increasing doses of L, B, or R according to a randomized protocol. The doses administered were 0. 375, 0.75, 1.5, 3.0, and 4.0 mg, with further doses increasing in 1-mg increments until death occurred. Plotting the mean maximum QRS interval as a function of the log(10) mmol dose allowed the following cardiotoxicity potency ratios to be determined for a doubling of QRS duration-B:L:R = 2.1:1.4:1. The lethal doses in millimoles (median/range) for L and R were (0.028/0.024-0.031) and (0.032/0.013-0.032), respectively, and were significantly higher than for B (0.015/0.012-0.019) - (P < 0.05, n = 7 for all groups). The lethal dose did not differ between R and L. Thus, the cardiotoxicity potency ratios for the three anesthetics based on lethal dose were: 2.1:1.2:1. If the anesthetic potencies for B and L are similar, the latter should have less potential for cardiotoxicity in the clinical situation. Implications: Animal experiments have shown levobupivacaine and ropivacaine to be less cardiotoxic than racemic bupivacaine. This in vivo study, using a validated swine model, compared the relative direct cardiotoxicities of these three local anesthetics. The lethal dose did not differ between levobupivacaine and ropivacaine, but was lowest for racemic bupivacaine.     

Adding sufentanil to levobupivacaine or ropivacaine intrathecal anaesthesia affects the minimum local anaesthetic dose required

Background: We carried out this prospective, randomized, double-blind study in order to evaluate whether the intrathecal addition of sufentanil 3.3 mcg affects both the minimum local anaesthetic dose (MLAD) of spinal levobupivacaine and ropivacaine for a caesarean section and enhances the spinal block characteristics.
Methods: One hundred and eighty women were randomly allocated into four groups: levobupivacaine (Group L), levobupivacaine plus sufentanil (Group L+S), ropivacaine (Group R) and ropivacaine plus sufentanil (Group R+S). Each received 3 ml of the study solution intrathecally as part of a combined spinal/epidural technique. The initial dose was 12 mg for Groups L and L+S, and 15 mg for Groups R and R+S. The test solution was required to achieve a visual analogue pain score (VAPS) of 30 mm or less to be considered effective at skin incision, uterine incision, birth, peritoneal closure and at the conclusion of surgery. Effective or ineffective responses determined a 0.5 mg decrease or increase of the same drug, respectively, for the next patient in the same group, using an up–down sequential allocation.
Results: Using the Dixon and Massey formula, the MLAD was 10.65 mg [confidence interval (CI) 95%: 10.14–11.56] in Group L, 4.73 mg (CI 95%: 4.39–5.07) in Group L+S, 14.12 mg (CI 95%: 13.50–14.60) in Group R and 6.44 mg (CI 95%: 5.86–7.02) in Group R+S.
Conclusions: The addition of sufentanil reduced the MLAD of both the local anaesthetics. It did not affect their potency ratio significantly and resulted in enhanced spinal anaesthesia.