High-dose bupivacaine, levobupivacaine and ropivacaine in axillary brachial plexus block

BACKGROUND: Racemic bupivacaine is clinically similar to levobupivacaine, or ropivacaine. The drugs were compared in brachial plexus block for the first time in the same randomized and double-blind study. METHODS: In 90 patients scheduled for hand and forearm surgery, a perivascular axillary brachial plexus block was performed with 45 ml of 5 mg ml(-1) of either racemic bupivacaine-HCl, levobupivacaine-HCl, or ropivacaine-HCl. Sensory (cold) and motor (hand clasp, and movement of elbow) block were scored, and the patient was interviewed in the postoperative evening and the following morning. Time to normal function of the arm was registered. RESULTS: After similar onsets of sensory block, the sum of completely anaesthetized innervation areas of the four main nerves at 45 min was greater in the ropivacaine group than in the levobupivacaine group (P < 0.01). Simultaneously, complete motor block at the elbow was more frequent in the ropivacaine group (67%) than in the bupivacaine (47%) and levobupivacaine groups (30%) (P < 0.01). In the hand, the corresponding results were 83%, 77%, and 57%, respectively (NS). Two patients in the levobupivacaine and one in the ropivacaine group needed general anaesthesia. Mean duration of the blocks was similar in the bupivacaine, levobupivacaine and ropivacaine groups at 19.3 h, 19.5 h, and 17.3 h, respectively (NS). Two patients were dissatisfied with the long block duration. CONCLUSION: Ropivacaine-HCl 5 mg ml(-1) produced slightly better sensory and motor block intensity than the same dose of levobupivacaine-HCl. General success in relation to surgery and in the duration of the blocks was similar in the three groups.     

Levobupivacaine and ropivacaine in the infraclavicular brachial plexus block

AIM: Infraclavicular brachial plexus block were first described by Raj, yet this block remained underutilized despite theoretical advantages. The aim of this prospective, randomized study was to compare equipotent doses of levobupivacaine and ropivacaine. METHODS: For this prospective, randomized study we have enrolled, after informed consent, 30 patients of both sexes, ASA status I-II, who were going to receive surgery to the forearm or hand with tourniquet position on the arm. The infraclavicular plexus block was performed by using vertical technique. The block was performed with 30 mL of levobupivacaine 0.5% or ropivacaine 0.75%. RESULTS: No differences were reported between 2 groups in terms of demographic data. The onset-time for motor block was greater for ropivacaine group (p<0.05); the sensitive block was longer in levobupivacaine group (p<0.05). CONCLUSIONS: The long duration of sensory block associated with the with good analgesia, less toxicity and the pharmacodynamic properties of levobupivacaine include this new local anaesthetic as a valid choice respect other local anaesthetic for infraclavicular plexus block.     

Lumbar plexus and sciatic nerve block for knee arthroplasty: comparison of ropivacaine and bupivacaine

PURPOSE: Information about the onset time and duration of action of ropivacaine during a combined lumbar plexus and sciatic nerve block is not available. This study compares bupivacaine and ropivacaine to determine the optimal long-acting local anaesthetic for lumbar plexus and sciatic nerve block in patients undergoing total knee arthroplasty. METHODS: Forty adult patients scheduled for unilateral total knee arthroplasty, under lumbar plexus and sciatic block were entered into this double-blind randomized study. Patients were assigned (20 per group) to receive lumbar plexus block using 30 ml of local anaesthetic and a sciatic nerve block using 15 ml of local anaesthetic with either bupivacaine 0.5% or ropivacaine 0.5%. All solutions contained fresh epinephrine in a 1:400,000 concentration. Every one minute after local anaesthetic injection, patients were assessed to determine loss of motor function and loss of pinprick sensation in the L1-S1 dermatomes. The time to request first analgesic was documented from the PCA pump. This time was used as evidence of block regression. RESULTS: Blocks failed in four patients in each group. The mean onset time of both motor and sensory blockade was between 14 and 18 min in both groups. Duration of sensory blockade was longer in the bupivacaine group, 17 +/- 3 hr, than in the ropivacaine group, 13 +/- 2 hr (P < 0.0001). CONCLUSION: We conclude that bupivacaine 0.5% and ropivacaine 0.5% have a similar onset of motor and sensory blockade when used for lumbar plexus and sciatic nerve block. Analgesic duration from bupivacaine 0.5% was prolonged by four hours compared with an equal volume of ropivacaine 0.5%.     

Comparative study of different concentrations of prilocaine and ropivacaine for intraoperative axillary brachial plexus block

BACKGROUND AND OBJECTIVE: To compare the anaesthetic characteristics in terms of onset and offset times of the sensory and motor blocks of prilocaine 1% and ropivacaine 0.75% alone and in different combinations when used for brachial plexus anaesthesia in axillary perivascular blocks. METHODS: After informed consent 96 ASA I-III patients undergoing forearm or hand surgery participated in this prospective, randomized, double-blind study. Patients received either prilocaine 1% 40 mL (G1), prilocaine 1% 30 mL and ropivacaine 0.75% 10 mL (G2), prilocaine 1% 20 mL and ropivacaine 0.75% 20 mL (G3) or ropivacaine 0.75% 40 mL (G4) for axillary perivascular brachial plexus anaesthesia. Onset and duration of sensory and motor blocks in the distribution of the musculocutaneous, radial, median and ulnar nerves were assessed. RESULTS: The onset time of the sensory and motor blocks of the whole brachial plexus differed only between patients in G4 with ropivacaine 0.75% 40 mL demonstrating a later motor onset in comparison to all other groups and a later sensory onset in comparison to G1 and G2 (P < 0.01). The addition of ropivacaine resulted in longer offset times of the sensory and motor blocks. The median offset time of the motor block was 179.5 min in G1, 262 min in G2, 389.5 min in G3 and 745 min in G4 (P < 0.01). The median offset time of the sensory block was 163.5 min in G1, 277 min in G2, 383.5 min in G3 and 784 min in G4 (P < 0.01). There was no difference in onset and offset times between sensory and motor blocks within the groups. CONCLUSIONS: For axillary perivascular brachial plexus block prilocaine 1% alone and in combination with ropivacaine 0.75% was similar in terms of onset of sensory and motor blocks but different in duration of sensory and motor blocks without a differential sensory and motor offset.     

Spinal anesthesia: comparison of plain ropivacaine, bupivacaine and levobupivacaine for lower abdominal surgery

This study was performed to compare the anesthetic efficacy and safety of three local anesthetic agents: racemic bupivacaine and its two isomers: ropivacaine and levobupivacaine, in patients undergoing lower abdominal surgery. One hundred-twenty patients, ASA I-III, were randomized to receive an intrathecal injection of one of three local anesthetic solutions. Group A (n = 40) received 3 ml of isobaric bupivacaine 5 mg/ml (15 mg). Group B (n = 40) received 3 ml of isobaric ropivacaine 5 mg/ml (15 mg). Group C (n = 40) received 3 ml of isobaric levobupivacaine 5 mg/ml (15 mg). The onset and duration of sensory block at dermatome level T8, maximum upper spread of sensory block, time for 2-segment regression of sensory block as well as the onset, intensity and duration of motor block were recorded, as were any adverse effects, such as bradycardia, hypotension, hypoxia, tremor, nausea and/or vomiting. Time to unassisted standing up and voluntary micturition was also recorded. The onset of motor block was significantly faster in the bupivacaine group compared with that in the ropivacaine group and almost the same of that in the levobupivacaine group (P < 0.05). Ropivacaine presented a shorter duration of both motor and sensory block than bupivacaine and levobupivacaine (P < 0.05). Bupivacaine required more often the use of a vasoactive drug (ephedrine) compared to both ropivacaine and levobupivacaine and of a sympathomimetic drug (atropine) compared to the ropivacaine group.     

Tramadol does not prolong the effect of ropivacaine 7.5 mg/ml for axillary brachial plexus block

BACKGROUND: The aim of this prospective, randomized, double-blind study was to evaluate the effect of the addition of tramadol to ropivacaine on the onset and duration of sensory and motor block, and duration of analgesia, for axillary brachial plexus block. METHODS: After institutional approval and informed consent had been obtained, 45 patients scheduled for forearm or hand surgery under axillary brachial plexus block were randomly allocated into two groups. The ropivacaine group received 40 ml of ropivacaine 7.5 mg/ml plus 2 ml of isotonic sodium chloride solution, and the tramadol group received 40 ml of ropivacaine 7.5 mg/ml plus 2 ml (100 mg) of tramadol. The onset and duration of sensory and motor block in the distribution of the musculocutaneous, radial, median and ulnar nerves, the duration of analgesia, the time to first pain medication, hemodynamics and side-effects were recorded. RESULTS: The addition of tramadol did not improve the speed of onset or increase the duration of sensory and motor block. The durations of analgesia were 631 +/- 33 min and 633 +/- 37 min (mean +/- standard deviation) in the ropivacaine and tramadol groups, respectively (P > 0.05). Hemodynamic parameters and side-effects did not differ between the groups. CONCLUSION: The addition of 100 mg of tramadol to 7.5 mg/ml of ropivacaine, for axillary brachial plexus block, does not prolong the duration of motor and sensory block and analgesia.     

A multicentre trial of ropivacaine 7.5 mg·ml−1 vs bupivacaine 5 mg·ml−1 for supra clavicular brachial plexus anesthesia

PURPOSE: To compare the efficacy of ropivacaine 7.5 mg x ml(-1) with bupivacaine 5.0 mg x ml(-1) for subclavian perivascular brachial plexus block. METHODS: After informed consent, 104 ASA I-III adults participated in a randomized, double-blind, multi-center trial to receive 30 ml of either ropivacaine 7.5 mg x ml(-1) or bupivacaine 5.0 mg x ml(-1) for subclavian perivascular brachial plexus block prior to upper limb surgery. Onset and duration of sensory and motor block in the distribution of the axillary, median, musculo-cutaneous, radial and ulnar nerves were assessed. RESULTS: Onset times and duration of sensory and motor block were similar between groups. Mean duration of analgesia for the five nerves was between 11.3 and 14.3 hr with ropivacaine and between 10.3 and 17.1 hr with bupivacaine. Quality of muscle relaxation judged as excellent by the investigators was not significantly different (ropivacaine - 35/49, bupivacaine - 30/49). The median time to first request for analgesia was comparable between the two groups (11-12 hr). One patient developed a grand mal seizure shortly after receiving bupivacaine and recovered consciousness within 30 min. There were no serious adverse events in the ropivacaine group. CONCLUSIONS: Thirty ml ropivacaine 7.5 mg x ml(-1) (225 mg) produced effective and well tolerated brachial plexus block of long duration by the subclavian perivascular route. In this study, the results were similar to those of 30 ml bupivacaine 5.0 mg x ml(-1).     

Increasing the injection volume by dilution improves the onset of motor blockade,but not sensory blockade of ropivacaine for brachial plexus block

BACKGROUND AND OBJECTIVE: Ropivacaine used for axillary plexus block provides effective motor and sensory blockade. Varying clinical dosage recommendations exist. Increasing the dosage by increasing the concentration showed no improvement in onset. We compared the behaviour of a constant dose of ropivacaine 150 mg diluted in a 30, 40 or 60 mL injection volume for axillary (brachial) plexus block. METHODS: A prospective, randomized, observer-blinded study on patients undergoing elective hand surgery was conducted in a community hospital. Three groups of patients with a constant dose of ropivacaine 150 mg, diluted in 30,40 or 60 mL NaCl 0.9%, for axillary plexus blockade were compared for onset times of motor and sensory block onset by assessing muscle strength, two-point discrimination and constant-touch sensation. RESULTS: Increasing the injection volume of ropivacaine 150 mg to 60 mL led to a faster onset of motor block, but not of sensory block, in axillary plexus block, compared with 30 or 40 mL volumes of injection. CONCLUSIONS: The data show that the onset of motor, but not of sensory block, is accelerated by increasing the injection volume to 60 mL using ropivacaine 150 mg for axillary plexus block. This may be useful for a more rapid determination of whether the brachial plexus block is effective. However, when performing surgery in the area of the block, sensory block onset seems more important.     

A comparative study of 0.25% ropivacaine and 0.25% bupivacaine for brachial plexus block.

The present study compares the effectiveness of 0.25% ropivacaine and 0.25% bupivacaine in 44 patients receiving a subclavian perivascular brachial plexus block for upper extremity surgery. The patients were assigned to two equal groups in this randomized, double-blind study; one group received ropivacaine 0.25% (112.5 mg) and the other, bupivacaine 0.25% (112.5 mg), both without epinephrine. Onset times for analgesia and anesthesia in each of the C-5 through T-1 brachial plexus dermatomes did not differ significantly between the two groups. The mean onset time for analgesia ranged from 11.2 to 20.2 min, and the mean onset time for anesthesia ranged from 23.3 to 48.2 min. The onset of motor block differed only with respect to paresis in the hand, with bupivacaine demonstrating a shorter onset time than ropivacaine. The duration of sensory and motor block also was not significantly different between the two groups. The mean duration of analgesia ranged from 9.2 to 13.0 h, and the mean duration of anesthesia ranged from 5.0 to 10.2 h. Both groups required supplementation with peripheral nerve blocks or general anesthesia in a large number of cases, with 9 of the 22 patients in the bupivacaine group and 8 of the 22 patients in the ropivacaine group requiring supplementation to allow surgery to begin. In view of the frequent need for supplementation noted with both 0.25% ropivacaine and 0.25% bupivacaine, we do not recommend using the 0.25% concentrations of these local anesthetics to provide brachial plexus block.     

右美托咪定对罗哌卡因腋路臂丛神经阻滞时效的影响

目的探讨右美托咪定与局麻药罗哌卡因混合用于腋路臂丛阻滞对阻滞效果及有效时间的影响。方法择期或急诊在腋路臂丛神经阻滞下行上肢手术患者60例,ASAⅠ或Ⅱ级,随机均分为:罗哌卡因+右美托咪定组(RD组)和罗哌卡因组(R组)。以神经刺激器定位腋路臂丛神经主分支(桡神经、正中神经、尺神经和肌皮神经),RD组和R组分别注射0.375%罗哌卡因40ml+右美托咪定1ml(1μg/kg)和0.375%罗哌卡因40ml+生理盐水1ml,记录感觉和运动神经阻滞起效时间、作用时间、镇痛时间、首次疼痛VAS评分;记录入室时(T0)、阻滞后5min(T1)、10min(T2)、15min(T3)、30min(T4)、60min(T5)HR、MAP、SpO2,记录不良反应的发生情况。结果与R组比较,RD组感觉和运动阻滞起效时间缩短,作用时间及术后镇痛时间延长(P<0.05)。与R组比较,T1～T5时RD组HR减慢(P<0.05),MAP差异无统计学意义;与T0时比较,T2～T5时两组MAP下降,T1～T5时HR减慢(P<0.05),但仍在正常范围;两组患者阻滞后SpO2差异无统计学意义。RD组有5例患者心动过缓;两组患者未出现恶心、呕吐、低血压、低氧血症及局麻药中毒等不良反应。结论右美托咪定1μg/kg与局麻药混合应用于腋路臂丛神经阻滞可增强罗哌卡因的镇痛效果,缩短起效时间,延长作用时间及术后镇痛时间,但是易诱发心动过缓。     

Addition of fentanyl to bupivacaine prolongs anesthesia and analgesia in axillary brachial plexus block

BACKGROUND AND OBJECTIVES: To evaluate the analgesic and anesthetic effects of 40 mL bupivacaine 0.25%, 40 mL bupivacaine 0.25% plus fentanyl 2.5 microg/mL, and 40 mL bupivacaine 0.125% plus fentanyl 2.5 microg/mL for axillary brachial plexus block. METHODS: Sixty patients were randomly allocated to 3 groups and received axillary brachial plexus block with 40 mL bupivacaine 0.25% (group B), 40 mL bupivacaine 0.25% with fentanyl 2.5 microg/mL (group BF), or 40 mL bupivacaine 0.125% with fentanyl 2.5 microg/mL (group DBF). The onset times and the duration of sensory and motor blocks, duration of analgesia, hemodynamic parameters, and adverse events were noted. RESULTS: The mean duration of sensory block and analgesia were longer in group BF (10.1 hours and 20.9 hours) than group B (6.9 hours and 11.6 hours) and DBF (5.9 hours and 12.0 hours) (P < .01, P < .001, respectively). The mean duration of motor block was also longer in group BF (10.7 hours) than group B (4.9 hours) (P < .01). Only 2 patients experienced motor block in group DBF. The frequency of successful block was 35% in group DBF (P < .01). Hemodynamic parameters were similar in all groups. In group B, only 1 patient experienced dizziness. Nausea was observed in 1 patient in each fentanyl group. CONCLUSION: The addition of 100 microg/mL fentanyl to 0.25% bupivacaine almost doubles the duration of analgesia following axillary brachial plexus block when compared with 0.25% bupivacaine alone.     

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.     

Convulsions following axillary brachial plexus blockade with levobupivacaine

Neurotoxicity manifesting as convulsions is a recognised complication of the administration of local anaesthetic drugs as part of a regional anaesthetic technique. We describe a case of self-limiting convulsions following the institution of an axillary brachial plexus block with levobupivacaine. Although the occurrence of convulsions following the administration of racemic bupivacaine is a well-recognised complication, there have been no clinical case reports published describing convulsions following the use of levobupivacaine in regional anaesthesia.     

Ropivacaine 7.5 mg/ml versus bupivacaine 5 mg/ml for interscalene brachial plexus block--a comparative study

We investigated ropivacaine 75 mg/ml in comparison with bupivacaine 5 mg/ml in patients receiving interscalene brachial plexus block (ISB) and general anaesthesia. In this randomized, double-blind, prospective clinical trial, each patient received an ISB block according to the technique originally described by Winnie and a catheter technique as per Meier. The rapidity of onset and the quality of sensory and motor block were determined. After general anaesthesia had been induced further parameters evaluated were consumption of local anaesthetic, opioid and neuromuscular blocking drug. After arrival in the recovery room, the patients were assessed for intensity of pain using a visual analog scale (VAS). One hundred and twenty patients were included in the study. The onset and development of sensory block was similar in both groups. Development and quality of motor block was also nearly identical for both local anaesthetics. Consumption of neuromuscular blocking drug and opioid did not differ between ropivacaine and bupivacaine. In the recovery room the mean pain score was less than 25 in both groups. There were no significant differences in terms of onset and quality of sensory or motor block during the intraoperative and early postoperative period. In addition we did not identify any side-effects related to the administration of the local anaesthetics. Ropivacaine 7.5 mg/ml and bupivacaine 5mg/ml proved to be nearly indistinguishable when administered for interscalene brachial plexus block.     

A comparison of epidural levobupivacaine 0.75% with racemic bupivacaine for lower abdominal surgery

Levobupivacaine, the S(-) isomer of bupivacaine, is less cardiotoxic than racemic bupivacaine. In this prospective, randomized, double-blinded study of epidural anesthesia, the onset, extent, and duration of sensory and motor block produced by 0.75% levobupivacaine (20 mL, 150 mg) was compared with that of 0.75% racemic bupivacaine in 56 patients undergoing elective lower abdominal surgery. The time to onset of adequate sensory block (T10 dermatome) was similar in both treatment groups (13.6 +/- 5.6 min for levobupivacaine and 14.0 +/- 9.9 min for bupivacaine), with an average peak block height of T5 reached at 24.3 +/- 9.4 and 26.5 +/- 13.2 min, respectively. Time to complete regression of sensory block was significantly longer with levobupivacaine (550.6 +/- 87.6 min) than bupivacaine (505.9 +/- 71.1 min) (P = 0.016). Abdominal muscle relaxation was adequate for the scheduled procedure in all patients, and there were no significant differences between the groups in rectus abdominis muscle scores (P = 0.386) and quality of muscle relaxation as determined by the surgeon and anesthesiologist (P = 0. 505 and 0.074, respectively). In conclusion, both 0.75% levobupivacaine and 0.75% bupivacaine produced effective epidural anesthesia and their effects were clinically indistinguishable. Implications: The results of this study indicate that the sensory and motor block produced by 0.75% levobupivacaine is equivalent to that of 0.75% racemic bupivacaine. Both local anesthetics are well tolerated and effective in producing epidural anesthesia for patients undergoing lower abdominal surgery.     

A comparison of 1% prilocaine with 0.5% ropivacaine for outpatient-based surgery under axillary brachial plexus block.

We compared the use of 1% prilocaine with 0.5% ropivacaine for axillary brachial plexus anesthesia in a double-blinded manner in day-stay patients to determine the better of the two local anesthetics in terms of onset time and duration of motor block. Sixty patients scheduled for outpatient upper-limb surgery were allocated randomly to receive either prilocaine (28 patients) or ropivacaine (32 patients) at a volume of 0.7 mL/kg. The brachial plexus was located with a plexus needle and nerve stimulator. By 20 min after injection of prilocaine or ropivacaine, there was no difference in analgesic effect. By this time, it was apparent whether or not a block was going to be adequate for surgery. Pain returned after a mean of 278 min (SD 111 min; range, 160-630 min) with prilocaine as compared with 636 min (SD 284 min; range, 210-1440 min) with ropivacaine. Analgesia use was similar in both groups. Duration of motor block with prilocaine was a mean of 254 min (SD 62 min; range, 130-385 min), as compared with 642 min (SD 199 min; range, 350-1080 min) with ropivacaine. We conclude that there is no clinically important difference between 1% prilocaine and 0.5% ropivacaine in time to onset of axillary brachial plexus block when they are injected in equal volumes. There is a significantly longer duration of action with ropivacaine, which may make it less suitable for day-stay upper-limb surgery because of the handicap from reduced muscle power. Implications: This study compares two local anesthetics to determine which is most suitable for day-stay upper-limb surgery under axillary brachial plexus block.Prilocaine 1% is more suitable than ropivacaine 0.5% because of a more prolonged duration of action of ropivacaine, although this could be useful in other circumstances.     

Levobupivacaine for axillary brachial plexus block: a pharmacokinetic and clinical comparison in patients with normal renal function or renal disease

We compared the pharmacokinetics and clinical characteristics of 0.5% levobupivacaine for axillary block in patients with normal renal function versus patients with end-stage renal disease (ESRD). Twenty patients with normal renal function and eight patients with ESRD received an axillary block with 50-60 mL of 0.5% levobupivacaine. Patients were evaluated for onset and duration of sensory/motor block. Eleven patients with normal renal function and eight patients with ESRD underwent pharmacokinetic analysis. No differences between groups were found in the onset, duration, or quality of block. The median time to sensory block was 12.5 min and 12.9 min, and mean duration of the block was 19 h and 22 h in normal versus ESRD patients, respectively. No significant differences in noncompartmental pharmacokinetic variables (median) were found between normal and ESRD patients with an AUC(0-t) (microg. h(-1). mL(-1)) of 11 and 13, peak concentration (C(max)) (microg/mL) of 1.2 and 1.6, and a time to peak concentration (T(max)) (min) of 55 and 48, respectively. This study demonstrates the clinical efficacy and equivalence of the pharmacokinetic characteristics of 0.5% levobupivacaine for axillary brachial plexus block in patients with ESRD and normal renal function. IMPLICATIONS: This study demonstrates the clinical efficacy and equivalence of the pharmacokinetic characteristics of 0.5% levobupivacaine for axillary brachial plexus block in patients with renal disease and normal renal function.     

The effects of clonidine on ropivacaine 0.75% in axillary perivascular brachial plexus block

INTRODUCTION: The new long-acting local anesthetic ropivacaine is a chemical congener of bupivacaine and mepivacaine. The admixture of clonidine to local anesthetics in peripheral nerve block has been reported to result in a prolonged block. The aim of the present study was to evaluate the effects of clonidine added to ropivacaine on onset, duration and quality of brachial plexus block. METHODS: Patients were randomly allocated into two groups. In group I brachial plexus was performed using 40 ml of ropivacaine 0.75% plus 1 ml of NaCL 0.9%, and in group II brachial plexus was performed using 40 ml of ropivacaine 0.75% plus 1 ml (0.150 mg) of clonidine. Onset of sensory and motor block of radial, ulnar, median and musculocutaneous nerve were recorded. Motor block was evaluated by quantification of muscle force, according to a rating scale from 6 (normal contraction force) to 0 (complete paralysis). Sensory block was evaluated by testing response to a pinprick in the associated innervation areas. Finally, the duration of the sensory block was registered. Data were expressed in mean+/-SD. For statistical analysis a Student t-test was used. A P-value of < or = 0.05 was considered as statistically significant. RESULTS: The duration of blockade was without significant difference between the groups. Group I: 718+/-90 min; Group II: 727+/-117 min. There was no intergroup difference in sensory and motor onset or in quality of blockade. CONCLUSION: The addition of clonidine to ropivacaine 0.75% does not lead to any advantage of block of the brachial plexus when compared with pure ropivacaine 0.75%.     

Brachial plexus block with a new local anaesthetic: 0.5 percent ropivacaine

A new local anaesthetic, ropivacaine hydrochloride, was used in a concentration of 0.5 per cent in 32 patients receiving a subclavian perivascular block for upper extremity surgery. One group (n = 15) received 0.5 per cent ropivacaine without epinephrine and a second group (n = 17) received 0.5 per cent ropivacaine with epinephrine in a concentration of 1:200,000. Anaesthesia was achieved in 87 per cent of the patients in both groups in all of the C5 through T1 brachial plexus dermatomes. Motor block was profound with 100 per cent of patients in both groups developing paresis at both the shoulder and hand and 100 per cent developing paralysis at the shoulder. There was a rapid initial onset of sensory block (a mean of less than four minutes for analgesia) with a prolonged duration (a mean of greater than 13 hr of analgesia). The addition of epinephrine did not significantly affect the quality or onset of sensory or motor block. The duration of sensory block was reduced by epinephrine at T1 for analgesia and at C7, C8, and T1 for anaesthesia. The duration of sensory block in the remaining brachial plexus dermatomes as well as the duration of motor block was not effected by epinephrine. There was no evidence of cardiovascular or central nervous system toxicity in either group with a mean dose of 2.5-2.6 mg.kg-1 ropivacaine.     

左旋布比卡因与罗哌卡因应用于臂丛神经阻滞的临床对比研究

目的 比较左旋布比卡因和罗哌卡因用于肌间沟臂丛神经阻滞的效果及不良反应。方法 本组自2007年5月～12月对60例行上肢手术患者，ASAI～Ⅱ级，分为罗哌卡因（R）组和左旋布比卡因（L）组，每组30例，采用肌间沟法行臂丛神经阻滞，观察感觉／运动神经阻滞的起效时间及持续时间、患者对神经阻滞满意度、不良反应。结果 两组间感觉神经和运动神经阻滞起效时间的差异无显著性（P〉0．05）；L组的感觉和运动神经阻滞持续时间显著长于R组（P〈0．05），神经阻滞优良率均为100％。结论 左旋布比卡因与罗哌卡因均可安全用于临床肌间沟臂丛神经阻滞，二者有相似的药效学特性，但左旋布比卡因在术后镇痛方面略优于罗哌卡因。