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

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.     

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

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.     

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.     

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

Objective To determine the median effective dose (ED50) for motor block after intrathecal bupivacaine and ievobupivacaine and define their motor-blocking potency ratios. Methods In this study ED50 was determined by up-down sequential allocation. Sixty ASA Ⅰ or Ⅱ patients aged 20-60 yr with body mass index <30 kg/m2/ undergoing elective gynecological surgery under combined spinal-epidural anesthesia were randomized into 2 groups receiving intrathecal 0.5% bupivacaine and levobupivacaine respectively. The initial dose was 5 mg.Each time the dose increased/decreased by 1 mg. Efficacy was determined by the occurrence of maximum motor block (Bromage scale = 3) in both lower limbs within 20 min after the spinal injection. Results Intrathecal ED50for motor block was 6.04 mg for bupivacaine (95% CI 5.30-6.93 mg), 9.55 mg for levobupivacaine (95% CI 8.62-10.97 mg) (P <0.01). The relative motor blocking potency ratio was levobupivacaine/bupivacalne 0.63 (95 % CI 0.52-0.75). Conclusion The potency of intrathecal levobupivacaine is lower than that of bupivacaine for motor block. The ratio is 0.63.     

剖宫产术患者不同比重罗哌卡因腰麻半数有效剂量的比较

目的 比较剖宫产术患者不同比重罗哌卡因腰麻的半数有效剂量(ED50).方法 择期脊椎-硬膜外联合麻醉下行剖宫产术的单胎足月初产妇40例,年龄20～40岁,采用随机数字表法,将其随机分为2组(n=20):重比重罗哌卡因组(HR组)和轻比重罗哌卡因组(LR组).经L2.3间隙行蛛网膜下腔穿刺,2组第1例患者局麻药的初始剂量均为9mg,HR组和LR组分别给予0.5％重比重和0.5％轻比重罗哌卡因,根据腰麻是否有效按照序贯法确定下一例患者的剂量,剂量间隔为1mg.采用概率单位法计算不同比重罗哌卡因腰麻的ED50及其95％可信区间(CI).结果 0.5％重比重和0.5％轻比重罗哌卡因腰麻的ED50分别为9.34 mg(95％CI 8.34～10.46 mg)和9.64 mg(95％CI 8.90～10.44 mg),二者ED50比较差异无统计学意义(P＞0.05).结论 剖宫产术患者0.5％重比重和0.5％轻比重罗哌卡因腰麻的ED50分别为9.34和9.64 mg,比重因素对罗哌卡因腰麻效果无影响.     

Intrathecal sufentanil (1.5 µg) added to hyperbaric bupivacaine (0.5%) for elective cesarean section provides adequate analgesia without need for pruritus therapy

Purpose We compared the effects of different doses of intrathecal sufentanil when administered together with hyperbaric bupivacaine for elective caesarean section. Methods This was a prospective, randomized, double-blind, controlled trial involving 100 pregnant women, American Society of Anesthesiologists (ASA) I-II, who were scheduled for elective caesarean section under spinal anesthesia. The patients were assigned to four groups according to the dose of sufentanil used: no sufentanil (group I; placebo) or 1.5, 2.5, or 5.0 μg sufentanil (groups 2–4, respectively). In every group, the local anesthetic used was hyperbaric bupivacaine 0.5% (12.5 mg), and the total volume of the solution was 3.5 ml. The duration of complete analgesia, maternal side effects, and maternal/fetal outcomes were recorded. The duration of complete analgesia was defined as the time from intrathecal injection to a vernal analogue score (VAS) of more than 0. Results No patient experienced intraoperative pain. The duration of complete analgesia was prolonged in all groups receiving opioids. The duration of the analgesia and the 0- to 6-h intravenous analgesic requirements were similar in the sufentanil groups. Moreover, the sufentanil groups had longer durations of complete analgesia than the placebo group. Pruritus was more frequent in the 2.5- and 5-μg sufentanil groups than in the 1.5-μg sufentanil and placebo groups. There were no differences among the groups in umbilical cord blood gases on in neonatal Apgar scores. Conclusion The addition of sufentanil 1.5 and 2.5 μg to hyperbaric bupivacaine provided adequate anesthesia for caesarean delivery and good postoperative analgesia. In addition, the incidence of pruritus was significantly lower in the 1.5-μg sufentanil group when compared with that in the 2.5- and 5-μg groups.     

舒芬太尼对老年患者蛛网膜下腔阻滞时罗哌卡因ED_(50)的影响

目的观察舒芬太尼联合罗哌卡因行蛛网膜下腔阻滞用于老年患者手术的效果,探讨舒芬太尼对老年患者蛛网膜下腔阻滞时罗哌卡因ED50的影响。方法择期行下肢或会阴部手术的老年患者48例,ASAⅠ~Ⅲ级,随机分为舒芬太尼组(S组)和对照组(C组)。选择L3~4椎间隙穿刺,S组为舒芬太尼和0.5%罗哌卡因,其中舒芬太尼固定为5.0 μg,C组为0.5%罗哌卡因,根据预实验结果及序贯法原则,S组第1例患者罗哌卡因给药剂量为8.0 mg,C组第1例患者罗哌卡因给药剂量为9.0 mg。此后如前一例患者符合有效标准则后一例患者给药剂量下调1.0 mg,反之则上调1.0 mg。ED50采用Dixon-Massey序贯法计算。结果舒芬太尼联合罗哌卡因用于老年患者腰麻下肢或会阴部手术的ED50为6.40 mg(95%CI:5.98~6.80mg),单纯罗哌卡因的ED50为8.42 mg(95%CI:7.79~9.03 mg)。与给药前比较,C组给药后3、6、15 min后MAP明显降低,且明显低于S组(P0.01),但均在正常范围内。结论老年患者蛛网膜下腔阻滞复合5.0 μg舒芬太尼时,罗哌卡因ED50降低。     

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.     

超声引导下罗哌卡因臂丛神经阻滞的半数有效浓度

目的 超声引导下罗哌卡因臂丛神经阻滞的半数有效浓度.方法 择期上肢手术患者50例,年龄19～72岁,体重45～83 ks,身高150～181 cm,ASA分级Ⅰ或Ⅱ级.超声引导下行臂丛神经阻滞,定位成功后注入罗哌卡因30 ml,初始浓度0.50%,浓度变化梯度为O.05%,阻滞有效则下一例采用低一级浓度,阻滞无效,则下一例采用高一级浓度.采用Prebit法计算超声引导下罗哌卡因臂丛神经阻滞的半数有效浓度及其95%可信区间.结果 超声引导下罗哌卡因臂丛神经阻滞的半数有效浓度为0.436%,95%可信区间为0.393%～0.477%.结论 超声引导下罗哌卡因臂丛神经阻滞的半数有效浓度为0.436%.

Abstract：

Objective To determine the median effective concentration (EC50) of ropivacaine for ultrasound-guided brachial plexus block.Methods Fifty ASA Ⅰ or Ⅱ patients of both sexes, aged 19-72 yr, weighing 45-83 kg, scheduled for upper extremity surgery under brachial plexus block guided by ultrasound, were enrolled in this study. Brachial plexus block was performed under the guidance of ultrasound. After successful location, ropivacaine 30 ml was injected. EC50 of ropivacaine was determined by up-and-down sequential method. The initial concentration was 0.50% . Each time the concentration increased/decreased by 0.05% . EC50 of ropivacaine required for ultrasound-guided brachial plexus block and 95% confidence interval were calculated using Probit analysis.Results The EC50 of ropivacaine resulting in complete block of the brachial plexus nerve was 0.436%(95% confidence interval 0.393%-0.477% ). Conclusion The EC50 of ropivacaine is 0.436% for ultrasoundguided brachial plexus block.     

重比重甲磺酸罗哌卡因复合舒芬太尼蛛网膜下腔注射用于剖宫产的最佳剂量

目的探讨重比重甲磺酸罗哌卡因复合舒芬太尼蛛网膜下腔注射用于剖宫产的最佳剂量。方法 31例ASAⅠ或Ⅱ级在腰-硬联合麻醉下行择期剖宫产的产妇,首先选择L1~2间隙进行硬膜外置管,然后在L3~4间隙进行蛛网膜下腔穿刺,在30 s内注入混合的重比重甲磺酸罗哌卡因溶液。注药后立即头低脚高位调节平面,到达T7平面时,将床摇平,并略向左侧倾斜。罗哌卡因起始剂量为13.410 mg,腰麻成功的定义为10 min内到达T7平面和术中手术条件满意,硬膜外不需要追加利多卡因完成手术。根据罗哌卡因腰麻成功或不成功的反应,采用改良Dixon序贯法,减少或者增加0.894 mg来确定下一个产妇的腰麻剂量。结果 Probit分析表明,复合5μg舒芬太尼时,重比重甲磺酸罗哌卡因半数有效剂量(ED50)为10.713 mg(95%的可信区间为10.126~11.236 mg),95%有效剂量(ED95)为12.002 mg(95%的可信区间11.405~14.547 mg)。结论复合5μg舒芬太尼时,重比重甲磺酸罗哌卡因使50%产妇行剖宫产时获得满意麻醉的最佳剂量为10.713mg。甲磺酸罗哌卡因适合用于剖宫产腰麻。     

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.     

Intrathecal sufentanil decreases the median effective dose (ED50) of intrathecal hyperbaric ropivacaine for caesarean delivery

Background: The addition of opioid to local anaesthetics has become a well‐accepted practice of spinal anaesthesia for caesarean delivery. Successful caesarean delivery anaesthesia has been reported with the use of a low dose of intrathecal hyperbaric ropivacaine coadministered with sufentanil. This prospective, double‐blinded study determined the median effective dose (ED50) of intrathecal hyperbaric ropivacaine with and without sufentanil for caesarean delivery, to quantify the sparing effect of sufentanil on the ED50 of intrathecal hyperbaric ropivacaine. Methods: Sixty‐four parturients undergoing elective caesarean delivery with combined spinal–epidural anaesthesia were randomized into two groups: Group R (ropivacaine) and Group RS (ropivacaine plus sufentanil 5 μg). The initial dose of ropivacaine was 13 mg in Group R and 10 mg in Group RS. The effective dose was defined as a T₆ level attained within 10 min and no supplemental epidural anaesthetic required during surgery. Effective or ineffective responses determined, respectively, a 0.3 mg decrease or increase of the dose of ropivacaine for the next patient using an up–down sequential allocation. Results: The ED50 of intrathecal ropivacaine was 11.2 mg [confidence interval (CI) 95%: 11.0–11.6] in Group R vs. 8.1 mg (CI 95%: 7.8–8.3) in Group RS. Motor block was markedly more intense in Group R than in Group RS, and the incidence of shivering was lower in Group RS than in Group R. There were no differences in the onset time of sensory block or motor block, in the incidence of hypotension, nausea and vomiting. Conclusion: Intrathecal sufentanil 5 μg produced a 28% reduction of ED50 of intrathecal hyperbaric ropivacaine for caesarean delivery.     

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 [mu]g 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).     

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.     

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.     

The relative motor blocking potencies of intrathecal ropivacaine: effects of concentration

This study established the median effective dose (ED(50)) for motor block of intrathecal 1% and 0.1% ropivacaine and determined the effects of the concentration of the solution injected on the motor block obtained. We enrolled into this prospective, randomized, double-blind, sequential allocation study 54 parturients undergoing elective Cesarean delivery under combined spinal-epidural technique. Parturients were randomized to receive intrathecal ropivacaine either 1% or 0.1%. The initial dose was chosen to be 4 mg, with subsequent doses being determined by the response of the previous patient (testing interval, 1 mg). The occurrence of any motor block in either lower limb within 5 min from the intrathecal injection of the study solution was considered effective. The motor block at 5 min was 6.1 mg for 1% ropivacaine (95% confidence interval [CI], 5.1-7.1) and was 9.1 mg (95% CI, 7.8-10.3) for 0.1% ropivacaine (P = 0.0013; 95% CI difference, 1.3-4.7). The relative efficacy ratio of the 2 concentrations was 1.5 (95% CI difference, 1.2-1.9) in favor of the larger concentration. The ED(50) of spinal ropivacaine to produce motor block in pregnant patients was significantly influenced by the concentration of the local anesthetic, with dose requirements being increased by 50% for the smaller concentration. IMPLICATIONS: The minimum local anesthetic dose for motor block with 0.1% ropivacaine is 50% larger than the 1% concentration with a relative efficacy ratio of 1.5. Our findings suggest that more diluted local anesthetic solutions determine less motor block, and this may be considered in ambulant laboring parturients.     

经尿道前列腺电切术老年患者鞘内注射不同局麻药的药效学

目的 探讨经尿道前列腺电切术老年患者鞘内注射不同局麻药的药效学.方法 择期拟在脊椎-硬膜外联合阻滞下行经尿道前列腺电切术的老年患者90例,ASA分级Ⅰ～Ⅲ级,年龄69～82岁,体重指数＜30 kg/m2,随机分为3组(n=30):左旋布比卡因组(L组)、罗哌卡因组(R组)和布比卡因组(B组)分别于蛛网膜下腔注射0.5%左旋布比卡因、0.5%罗哌卡因、0.5%布比卡因.采用序贯法进行试验,初始剂量分别为7、10、6 mg,相邻剂量比均为0.9.阻滞有效,则下一例采用低一级剂量;阻滞无效,则下一例采用高一级剂量.阻滞有效的标准为:蛛网膜下腔注药后20 min内感觉阻滞平面达T10.计算3种局麻药半数有效剂量(ED50)及其95%可信区间(95%CI).结果 经尿道前列腺电切术老年患者鞘内注射左旋布比卡因、罗哌卡因和布比卡因阻滞的ED50及其95%CI分别为6.781(6.561～7.024)mg、9.135(8.670～9.616)mg和5.170(5.012～5.333)mg.左旋布比卡因、罗哌卡因和布比卡因的效价比为0.76∶0.57∶1.00.结论 经尿道前列腺电切术老年患者鞘内注射左旋布比卡因、罗哌卡因和布比卡因阻滞的效价比为0.76∶0.57∶1.00.     

Spinal ropivacaine for cesarean section: a dose-finding study.

BACKGROUND: The dose-response relation for spinal ropivacaine is undetermined, and there are few data available for obstetric patients. METHODS: In a prospective, randomized, double-blind investigation, the authors studied 72 patients undergoing elective cesarean delivery. An epidural catheter was placed at the L2-L3 vertebral interspace. Lumbar puncture was then performed at the L3-L4 vertebral interspace, and patients were randomized to receive a dose of spinal ropivacaine diluted to 3 ml with normal saline: 10 mg (n = 12), 15 mg (n = 20), 20 mg (n = 20), or 25 mg (n = 20). Sensory changes assessed by ice and pin prick and motor changes assessed by modified Bromage score were recorded at timed intervals. A dose was considered effective if an upper sensory level to pin prick of T7 or above was achieved and epidural supplementation was not required intraoperatively. RESULTS: Anesthesia was successful in 8.3, 45, 70, and 90% of the 10-, 15-, 20-, and 25-mg groups, respectively. A sigmoid dose-response curve and a probit log dose-response plot were obtained, and the authors determined the ED50 (95% confidence interval) to be 16.7 (14.1-18.8) mg and the ED95 (95% confidence interval) to be 26.8 (23.6-34.1) mg. Duration of sensory and motor block and degree of motor block, but not onset of anesthesia, were positively related to dose. CONCLUSIONS: The ED50 and estimated ED95 for spinal ropivacaine were 16.7 and 26.8 mg, respectively. Ropivacaine is a suitable agent for spinal anesthesia for cesarean delivery.