芬太尼缩短硬膜外罗哌卡因起效时间的临床观察

罗哌卡因硬膜外阻滞起效时间偏长,而起效时间是评价临床硬膜外麻醉效果的重要指标,目前芬太尼对罗哌卡因起效时间的影响国内外尚无报道。本研究采用随机双盲法比较了 0.75％罗哌卡因中加入100μg芬太尼对硬膜外起效时间的影响及可能出现的副作用。     

罗哌卡因、布比卡因和利多卡因的中枢神经系统毒性作用及其对脑c-Fos蛋白表达的影响

罗哌卡因毒性作用小、低浓度时可使运动和感觉神经阻滞相分离而在临床麻醉和术后镇痛中得到广泛应用。但近来使用罗哌卡因导致毒性反应屡见报道^[1]。过去对罗哌卡因毒性作用的研究多注重于相同的毒性反应在剂量上和其他酰胺类局麻药的差异^[2]，而对罗哌卡因引起毒性反应的程度了解较少。本研究拟使用0．75％罗哌卡因、0．75％布比卡因和2％利多卡因的CD50(导致50％的小鼠发生惊厥的剂量)进行小白鼠腹腔注射，观察导致惊厥时间长短及对脑c-Fos表达的影响，以比较罗哌卡因、布比卡因和利多卡因引起毒性反应后严重程度的差异。     

不同浓度罗哌卡因用于腋路臂丛神经阻滞的研究

目的探讨0.25%、0.3%、0.375%罗哌卡因用于臂丛神经阻滞的有效性和安全性,并与0.25%布比卡因对照.方法选择ASAⅠ-Ⅱ级准备行上肢手术的病人80例,随机分为4组,每组20例,分别用0.25%、0.3%、0.375%罗哌卡因和0.25%布比卡因40ml行臂丛神经阻滞,观察病人有无不适症状,并分别对感觉和运动进行评价.结果随着浓度增加罗哌卡因麻醉强度依次增加,40m10.25%罗哌卡因麻醉强度明显低于0.25%布比卡因,且满意率低,仅为85%;将罗哌卡因浓度提高到0.375%,显示出与0.25%布比卡因相当的麻醉强度,满意率则提高到100%.结论 0.25%罗哌卡因用于臂丛神经阻滞起效慢、满意率低,不是临床使用的适宜浓度;0.3%、0.375%罗哌卡因起效快,作用完善,副作用少,可推荐用于长时间臂丛神经阻滞,而以0.375%罗哌卡因最为适宜.     

甲磺酸罗哌卡因和盐酸布比卡因硬膜外术后镇痛效果及对应激反应的影响

盐酸罗哌卡因是一种长效酰胺类局麻药，因其具有较小的心脏毒性而广泛应用于硬膜外麻醉和术后镇痛。甲磺酸罗哌卡因是将盐酸罗哌卡因的盐酸根改为甲磺酸根后的一种国产新型酰胺类局麻药。本研究比较甲磺酸罗哌卡因与盐酸布比卡因硬膜外术后镇痛临床效果及对术后应激反应的影响。     

0.75%罗哌卡因用于剖宫产手术硬膜外麻醉的研究

目的 评价０．７５％罗哌卡因用于硬膜外麻醉剖宫产手术的临床效果和耐受性,并以０．５％丁哌卡因作为对照组。方法 择期剖宫产手术病人６１例,硬膜外麻醉时随机分别接受０．７５％罗哌卡因或０．５％丁哌卡因,观察感觉阻滞,运动阻滞,术中疼痛,镇痛和腹壁肌松质量及不良反应。     

手术患者0.894%甲磺酸罗哌卡因与0.75%盐酸罗哌卡因硬膜外麻醉的效果

盐酸罗哌卡因是一种长效局部麻醉药,是纯S-对映体局麻药。与布比卡因相比,其中枢神经系统及心脏毒性较小,因此盐酸罗哌卡因是一种较理想的硬膜外局麻药。甲磺酸罗哌卡因是一种国产新型酰胺类局麻药,在化学结构上将盐酸罗哌卡因的盐酸根改为甲磺酸根,但其硬膜外麻醉的效果尚需进一步探讨。本研究拟采用多中心临床双盲随机对照试验方案,比较手术患者甲磺酸罗哌卡因与盐酸罗哌卡因硬膜外麻醉的效果。     

0.75%罗哌卡因和0.5%布比卡因用于硬膜外阻滞剖宫产手术的比较

目的 比较０．７５％罗哌卡因和０．５％布比卡因对剖宫产手术硬膜外麻醉的临床效果。为罗哌卡因临床应用提供客观依据。方法 ２０例剖宫产术患者（ＡＳＡⅠ～Ⅱ级）随机分为二组，Ｉ组：０．７５％罗派卡因（ｎ＝１０例），ＩＩ组：０．５％布比卡因（ｎ＝１０例）取Ｌ２－３行硬膜外穿刺，向上置管３ｃｍ，注入１．０％利多卡因５ｍｌ试验量，５分钟后注入首次剂量罗哌卡因或布比卡因８～１５ｍｌ总量不超过２０ｍｌ，结果：两组     

论著：不同浓度罗哌卡因用于腋路臂丛神经阻滞的研究

目的 探讨0．25％、0．3％、0．375％罗哌卡因用于臂丛神经阻滞的有效性和安全性，并与0．25％布比卡因对照。方法 选择ASA Ⅰ-Ⅱ级准备行上肢手术的病人80例，随机分为4组，每组20例，分别用0．25％、0．3％、0．375％罗哌卡因和0．25％布比卡因40ml行臂丛神经阻滞，观察病人有无不适症状，并分别对感觉和运动进行评价。结果 随着浓度增加罗哌卡因麻醉强度依次增加，40ml0．25％罗哌卡因麻醉强度明显低于0．25％布比卡因，且满意率低，仅为85％；将罗哌卡因浓度提高到0．375％，显示出与0．25％布比卡因相当的麻醉强度，满意率则提高到100％。结论 0．25％罗哌卡因用于臂丛神经阻滞起效慢、满意率低，不是临床使用的适宜浓度；0．3％、0．375％罗哌卡因起效快，作用完善，副作用少，可推荐用于长时间臂丛神经阻滞，而以0．375％罗哌卡因最为适宜。     

术后自控硬膜外罗哌卡因-芬太尼镇痛的临床研究

目的 研究三种不同浓度的罗哌卡因复合芬太尼作术后硬膜外自控镇痛的效果。方法 60例剖宫产孕妇随机分为0．2％罗哌卡因—lμg／m1芬太尼，0．1％罗哌卡因—2μg／m1芬太尼和0．05％罗哌卡因—5μg／m1芬太尼三组。采用视觉模拟评分(VAS)，镇静评分(SS)和运动阻滞评分(Bromage)。结果 三组产妇镇痛效果良好且无显著性差别(P＞0．05)。0．2％罗哌卡因组运动阻滞明显大于0．1％罗哌卡因组和0．05％罗哌卡因组(P＜0．05)。结论 0．1％罗哌卡因辅以芬太尼能产生良好的术后镇痛，且对运动神经影响小，可以在临床上广泛应用。     

0.1%罗哌卡因与0.1%布比卡因复合芬太尼硬膜外分娩镇痛

罗哌卡因是一种新型长效酰胺类局麻药 ,其化学结构与布比卡因相似 ,但对中枢神经及心血管毒性明显低于布比卡因[1] 。低浓度时 ,罗哌卡因对感觉和运动神经可呈分离阻滞[2 ] 。本研究拟观察小剂量罗哌卡因合并芬太尼硬膜外持续输注进行分娩镇痛的临床效果 ,并与相同浓度的布比卡因进行比较。资料与方法采用随机、双盲、对照、平行试验。对自愿接受无痛分娩的 6 0例名足月初产妇 ,年龄 2 1～ 31岁 ,ＡＳＡ分级 1～ 2级 ,随机分为 (1)试验组 :罗哌卡因组 (Ｒ组 )和 (2 )对照组 :布比卡因组 (Ｂ组 )。Ｒ组 ,负荷剂量 :罗哌卡因 10ｍｇ 0 1ｍｇ…     

0.75% and 0.5% ropivacaine for axillary brachial plexus block: a clinical comparison with 0.5% bupivacaine

BACKGROUND AND OBJECTIVES: Although ropivacaine has been extensively studied for epidural anesthesia, very few reports exist on brachial plexus block. We therefore decided to investigate the clinical features of axillary brachial plexus anesthesia with two different concentrations of ropivacaine (0.5% and 0.75%) and to compare the results with those obtained with 0.5% bupivacaine. METHODS: Three groups of patients were randomized and prospectively studied. They received, in a double-blind fashion, 32 mL of the local anesthetic solution into the midaxilla, by a nerve-stimulator technique. Onset time in each of the stimulated nerves was recorded both for the sensory and motor block. Peak time (ready to surgery), rate of supplemental blocks, need for intraoperative opioids, duration of sensory and motor block, postoperative analgesic requirements, and patient satisfaction were also recorded. RESULTS: The rate of complete sensory and motor block observed with both ropivacaine groups was higher at 10, 15, and 20 minutes postinjection (P < .001). The mean peak time was shorter with ropivacaine than with bupivacaine (R50 = 16.37 minutes, R75 = 14.7 minutes, B = 22.3 minutes, P < .05). The quality of the anesthesia was higher with ropivacaine, as measured by the intraoperative needs for opioids and the overall patient's satisfaction (P < .05). No significant differences were noted with all the other studied parameters. CONCLUSION: Ropivacaine showed advantages over bupivacaine for axillary brachial plexus block. Because no statistical differences were found between the two ropivacaine groups, we therefore conclude that 0.75% does not add benefit and that 0.5% ropivacaine should be used to perform axillary brachial plexus blocks.     

Hyperbaric spinal ropivacaine: a comparison to bupivacaine in volunteers

BACKGROUND: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia. METHODS: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant. RESULTS: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given. CONCLUSION: Ropivacaine is half as potent and in equipotent doses has a similar profile to bupivacaine with a higher incidence of side effects. Low-dose hyperbaric spinal ropivacaine does not appear to offer an advantage over bupivacaine for use in outpatient anesthesia.     

Hyperbaric spinal ropivacaine for cesarean delivery: a comparison to hyperbaric bupivacaine.

We evaluated the clinical efficacy and safety of spinal anesthesia with 0.5% hyperbaric ropivacaine compared with 0.5% hyperbaric bupivacaine for elective cesarean delivery. Sixty healthy, full-term parturients were randomly assigned to receive either 12 mg of 0.5% hyperbaric bupivacaine or 18 mg of 0.5% hyperbaric ropivacaine intrathecally. There were no significant differences in demographic or surgical variables or neonatal outcomes between groups. Onset time of sensory block to T10 or to peak level was later in the Ropivacaine group (P < 0.05). The median (range) peak level of analgesia was T3 (T1-5) in the Bupivacaine group and T3 (T1-4) in the Ropivacaine group. Time for sensory block to recede to T10 did not differ between groups. Duration of sensory block was shorter in the Ropivacaine group (188.5 +/- 28.2 min vs 162.5 +/- 20.2 min; P < 0.05). Complete motor block of the lower extremities was obtained in all patients. Ropivacaine also produced a shorter duration of motor blockade than bupivacaine (113.7 +/- 18.6 min vs 158.7 +/- 31.2 min; P < 0.000). The intraoperative quality of anesthesia was excellent and similar in both groups. Side effects did not differ between groups. Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12 mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery Implications: Eighteen milligrams of 0.5% hyperbaric ropivacaine provided effective spinal anesthesia with shorter duration of sensory and motor block, compared with 12mg of 0.5% hyperbaric bupivacaine when administered for cesarean delivery.     

A comparison of intrathecal plain solutions containing ropivacaine 20 or 15 mg versus bupivacaine 10 mg

Ropivacaine, which blocks sensory nerve fibers more readily than motor fibers, is considered to be less potent than bupivacaine. Our hypothesis was that, when used in spinal anesthesia for day surgery, ropivacaine 15 and 20 mg would provide faster motor recovery than bupivacaine 10 mg. This prospective, randomized, double-blinded study included 90 ambulatory lower-extremity surgery patients who received 2 mL of ropivacaine 1%, ropivacaine 0.75%, or bupivacaine 0.5%. Motor block was tested with the Bromage scale, and sensory block was tested with pinprick. Ropivacaine 15 mg provided faster recovery of motor block (150 min) than did bupivacaine 10 mg (210 min; P = 0.005), but the median duration of sensory block at T10 (140 min) did not differ significantly from that with bupivacaine 10 mg (140 min). The median duration of sensory block at T10 was significantly longer with ropivacaine 20 mg (170 min) than with bupivacaine 10 mg (140 min; P = 0.005), but the median recovery from motor block (210 min) did not differ significantly. We conclude that the duration of sensory block of ropivacaine was two thirds and the duration of motor block was half when compared with bupivacaine, with calculations based on the duration-per-milligram of the local anesthetic.     

Clinical Effects and Maternal and Fetal Plasma Concentrations of Epidural Ropivacaine Versus Bupivacaine for Cesarean Section

Background: Ropivacaine is a new amide local anesthetic structurally similar to bupivacaine and mepivacaine. Previous studies showed that ropivacaine has a similar clinical effect as bupivacaine with regard to sensory anesthesia and slightly less motor blockade than bupivacaine. Ropivacaine appears to be less cardiotoxic and arrhythmogenic than bupivacaine. The clinical and pharmacokinetic effects of 0.5% ropivacaine (5 mg/ml) versus 0.5% bupivacaine (5 mg/ml) when used epidurally for elective cesarean section were investigated.

Methods: Using a randomized, double-blind study design, 60 ASA physical status 1 or 2 term parturients presenting for elective cesarean section received either 0.5% bupivacaine (150 mg) or 0.5% ropivacaine (150 mg) epidurally in appropriate fractionated doses over a 10-min period. Onset, duration, and regression of sensory and motor blockade were noted until complete resolution was observed. Quality of intraoperative anesthesia and abdominal wall muscle relaxation were noted. Maternal plasma concentrations of local anesthetic were determined before anesthetic administration and 5, 10, 20, 30, and 60 min and 2, 3, 6, 8, 12, and 24 h after drug injection in 20 subjects. Umbilical cord blood was obtained at time of delivery for acid-base values and determination of the free and total plasma concentration of local anesthetic. Neonates also were examined for neurobehavioral assessments by Scanlon's and Neurologic and Adaptive Capacity Scores at 2 and 24 h after delivery.

Results: All patients received satisfactory anesthesia for operation. The onset, duration, and regression of sensory blockade were similar for both groups. Onset of degree 1 and 2 motor blockade was faster, and duration of degree 1 motor block was longer in the group receiving bupivacaine. Hemodynamic sequelae were similar between groups. All neonates had 5-min Apgar scores of 7 or greater and normal acid-base values and neurobehavioral assessments. Pharmacokinetic analysis showed that the Cmax was similar for both drugs (1.3 plus/minus 0.09 for ropivacaine and 1.1 plus/minus 0.09 micro gram/ml for bupivacaine). The T1/2 of the terminal decline in plasma concentration was shorter for ropivacaine versus bupivacaine (5.2 plus/minus 0.60 versus 10.9 plus/minus 1.08 h, respectively; P < 0.01). The free (i.e., unbound) concentrations of ropivacaine were approximately twice those of bupivacaine in both maternal and neonatal blood at the time of delivery. The ratio of umbilical vein to maternal vein concentration of unbound drug was 0.72 for ropivacaine and 0.69 for bupivacaine.     

The relative motor blocking potencies of epidural bupivacaine and ropivacaine in labor

Minimal local analgesic concentrations (MLAC) have been used to determine the epidural analgesic potencies of bupivacaine and ropivacaine. There are no reports of the motor blocking potencies of these drugs. We sought to determine the motor block MLAC of both drugs and their relative potency ratio. Sixty ASA physical status I and II parturients were randomized to one of two groups, during the first stage of labor. Each received a 20-mL bolus of epidural bupivacaine or ropivacaine. The first woman in each group received 0.35%. Up-down sequential allocation was used to determine subsequent concentrations at a testing interval of 0.025%. Effective motor block was defined as a Bromage score <4 within 30 min. The up-down sequences were analyzed by using the Dixon and Massey method and probit regression to quantify the motor block minimal local analgesic concentration. Two-sided P < 0.05 defined significance. The motor block minimal local analgesic concentration for bupivacaine was 0.326% (95% confidence interval [CI], 0.285-0.367) and for ropivacaine was 0.497% (95% CI, 0.431-0.563) (P = 0.0008). The ropivacaine/bupivacaine potency ratio was 0.66 (95% CI, 0.52-0.82). This is the first MLAC study to estimate the motor blocking potencies of bupivacaine and ropivacaine. Ropivacaine was significantly less potent for motor block, at 66% that of bupivacaine. IMPLICATIONS:The results of this study demonstrate that epidural ropivacaine is less potent than epidural bupivacaine in producing motor blockade during labor. The motor block potency relation is similar to the sensory potency ratio for these two drugs.     

Hyperbaric Spinal Ropivacaine: A Comparison to Bupivacaine in Volunteers

Background: Ropivacaine is a newly introduced local anesthetic that may be a useful alternative to low-dose bupivacaine for outpatient spinal anesthesia. However, its relative potency to bupivacaine and its dose-response characteristics are unknown. This double-blind, randomized, crossover study was designed to determine relative potencies of low-dose hyperbaric spinal ropivacaine and bupivacaine and to assess the suitability of spinal ropivacaine for outpatient anesthesia.

Methods: Eighteen healthy volunteers were randomized into three equal groups to receive one spinal administration with bupivacaine and a second with ropivacaine, of equal-milligram doses (4, 8, or 12 mg) of 0.25% drug with 5% dextrose. The duration of blockade was assessed with (1) pinprick, (2) transcutaneous electrical stimulation, (3) tolerance to high tourniquet, (4) electromyography and isometric force dynamometry, and (5) achievement of discharge criteria. Differences between ropivacaine and bupivacaine were assessed with linear and multiple regression. P < 0.05 was considered significant.

Results: Ropivacaine and bupivacaine provided dose-dependent prolongation of sensory and motor block and time until achievement of discharge criteria (R2 ranges from 0.33-0.99; P values from < 0.001 through 0.01). Spinal anesthesia with ropivacaine was significantly different from bupivacaine and was approximately half as potent for all criteria studied. A high incidence of back pain (28%; P = 0.098) was noted after intrathecal ropivacaine was given.     

Primary evaluation of the local anaesthetic properties of the amino amide agent ropivacaine (LEA 103)

The local anaesthestic properties of 1-propyl-2',6'-pipecoloxylidide, a congener of mepivacaine and bupivacaine, and its enantiomers were compared in animals. The (S)-enantiomer (ropivacaine, LEA 103) produced a longer duration of sciatic nerve block and infiltration anaesthesia than the racemate and the (R)-form. Ropivacaine and bupivacaine were equally potent in terms of block of evoked action potential in vitro and minimum effective concentration in vivo. Ropivacaine 0.25-1.0% was distinctly longer acting than bupivacaine on infiltration, equally effective in sciatic and brachial plexus block and somewhat shorter lasting in epidural and spinal blockade. There were tendencies towards a greater benefit from the addition of adrenaline with ropivacaine in epidural anaesthesia and a shorter latency to block in some of the tests. Ropivacaine seems less vasodilative than bupivacaine and capable of producing some vasoconstriction over a wider range of low concentrations, which may explain its longer duration of intradermal anaesthesia. The somewhat shorter duration of central blockade of ropivacaine is probably a result of lesser lipid solubility. Ropivacaine was less toxic (i.v. and s.c. LD50-values) than bupivacaine but more toxic than lidocaine, and produced only weak local irritation. Due to a combination of interesting local anaesthetic properties and relative safety including cardiotoxic potential, we consider ropivacaine a candidate for further studies.     

Comparison of 0.5% ropivacaine and 0.5% bupivacaine for epidural anesthesia in patients undergoing lower-extremity surgery

Ropivacaine is an amide local anesthetic structurally related to, but appearing less cardiotoxic, than bupivacaine. The authors' investigation was designed in a randomized, double-blind fashion to compare the clinical effectiveness of ropivacaine and bupivacaine in patients undergoing lower-extremity surgery. Forty-five patients were randomized to receive 20 ml of 0.5% ropivacaine or bupivacaine. Intermittent sensory (pinprick) and motor (Bromage score) measurements were made while the block was in effect, and changes in heart rate, blood pressure and amounts of additional analgesics, sedatives and other medications were also recorded. Presence of tourniquet pain and the quality of anesthesia were also assessed. One patient was excluded from analysis; thus, 22 patients each received ropivacaine or bupivacaine. No differences were found in patient or perioperative characteristics between the groups. The quality and extent of sensory and motor blockade between groups were comparable, although bupivacaine was slightly longer acting. Cardiovascular changes, incidence of tourniquet pain, and the amounts of supplemental medications necessary were also similar between groups. The authors found 0.5% ropivacaine and bupivacaine to be clinically similar in both sensory- and motor-blocking characteristics, with the exception that bupivacaine produced a blockade of slightly longer duration. Because ropivacaine is reported to be less cardiotoxic than bupivacaine in animal studies, the similarity of clinical epidural anesthesia may make ropivacaine the preferred agent.     

The place of ropivacaine in anesthesia

Ropivacaine has two advantages over bupivacaine. It provides more differential block when given epidurally, allowing for a better separation between sensory and motor block. This feature can be used to its advantage in obstetrics and in postoperative epidural pain relief. Ropivacaine has a lower systemic toxicity than both racemic and levobupivacaine. Especially its better cardiotoxic profile has been well documented and is an important advantage when using techniques with a potential for high plasma concentrations. Ropivacaine is less potent than bupivacaine and has a shorter duration of action. The magnitude of this potency difference however is not clearly quantified and differs with varying techniques. In some studies, the potency difference amounts up to 50% whereas in other studies the difference is negligible. The lower systemic toxicity of ropivacaine compared to bupivacaine is not offset by a lower potency, as ropivacaine in a 50% higher dose is still less cardiotoxic.