Profound motor blockade with epidural ropivacaine following spinal bupivacaine

Ropivacaine, a relatively new amide local anaesthetic, reputedly produces less motor block than equivalent doses of bupivacaine, potentially combining high-quality analgesia with the ability to ambulate. We report two cases of prolonged, profound motor block with patient-controlled epidural analgesia using 0.1% ropivacaine, following spinal bupivacaine for Caesarean section. As there was no evidence of inadvertent intrathecal ropivacaine administration or of any neurological injury, we hypothesise that epidural ropivacaine may interact with intrathecal bupivacaine to prolong its effect.     

Topical bupivacaine and etidocaine analgesia following fallopian tube banding

The purpose of this study was to compare the effectiveness and safety of etidocaine and bupivacaine for postoperative analgesia after laparoscope sterilization. The study was performed in 22 healthy patients who received either one per cent etidocaine, 2 mg.kg-1, or bupivacaine 1.5 mg.kg-1 in a double-blind, randomized fashion. The local anaesthetic was dropped onto the fallopian tubes from uterus to fimbriae before tubal occlusion. To establish safety, blood concentrations of the parent drug and its metabolites were measured before application and at 1, 3, 6, 10, 15, 30, 60 and 120 min. The mean peak concentrations were 501.8 +/- 71.3 (SEM) for etidocaine with a range of 225 to 905 ng.ml-1. For bupivacaine, the mean peak concentration was 468 +/- 73.8 SEM with a range from 191 to 1005 ng.ml-1. The mean values are one eighth of the toxic convulsive dose for humans. Etidocaine was metabolized at a faster rate than bupivacaine with a rapid appearance of 2-amino-2'-butyroxylidide (ABX). The bupivacaine metabolite 2,6-pipecoloxylidide (PPX) was detected in low concentrations in the 60-minute samples. We conclude that the topical application of either etidocaine or bupivacaine is a safe procedure in the doses and concentrations used during general anaesthesia for laparoscopic tubal banding.     

Cardiovascular effects of epidural local anaesthetics

The cardiovascular effects of 20 ml 0.75% bupivacaine with adrenaline 5 micrograms/ml injected epidurally were compared with those of 20 ml 0.75% ropivacaine with adrenaline. Cardiovascular measurements were performed with a transthoracic electrical bioimpedance monitor. The maximum mean arterial blood pressure decreased significantly from baseline values after both solutions, but the decrease after 20 minutes was more pronounced with bupivacaine (21%) than with ropivacaine (9.6%). Stroke volume increased significantly in both groups (52% for bupivacaine and 29% for ropivacaine). Cardiac output increased significantly from baseline values 2 minutes after epidural administration; the mean of the maximum increase was 64% for bupivacaine and 53% for ropivacaine (NS). The mean of the maximum increase of the ejection fraction was 13% in the bupivacaine group and 9% in the ropivacaine group, but was only significantly different from baseline values following bupivacaine. There was no difference in the onset time or height of the sensory block between the groups. The cardiovascular changes can be ascribed to sympathetic blockade and to systemic absorption of the local anaesthetics and adrenaline.     

布比卡因加芬太尼硬膜外阻滞对分娩的影响

目的：探讨低剂量布比卡因加芬太尼硬膜外阻滞镇痛对分娩的影响。方法：用0．125％布比卡因加芬太尼2．5μg／ml硬膜外阻滞镇痛的69例初产妇为镇痛组，与未行镇痛术69例同等条件的初产妇对照，用随机单盲方法进行临床观察。结果：低剂量布比卡因与芬太尼联合用药使硬膜外阻滞镇痛有效率达100％，并改善它缩性质，协调宫缩即缩短活跃期宫缩持续时间；松弛盆底肌肉，减轻抬头下降受阻，加速宫口开大及胎头下降（P＜0．01），缩短活跃期及第二产程（P＜0．01），减少胎儿宫内窘迫、产生出血及难产率。结论：0．125％布比卡因加芬太尼2．5μg／ml用于硬膜外阻滞镇痛是一种安全、有效无痛分娩术。     

Intervertebral epidural anaesthesia in paediatric surgery: success rate and adverse effects in 650 consecutive procedures

The success rate and occurrence of adverse effects are reported in a retrospective study of 650 (99 sacral, 468 lumbar, 76 thoracic and seven cervical) paediatric epidurals performed, mostly (91%) under light general anaesthesia, by several anaesthetists. Seventeen-gauge Tuohy and 20-gauge (Potts-Cournand® and Tuohy) needles were used. Anaesthetic solutions used were 1% lignocaine, 0.5% bupivacaine and a mixture of equal volumes of 0.5% bupivacaine with either 1% lignocaine or 1% etidocaine, all containing 1:200 000 adrenaline. The epidural space was identified by loss-of-resistance technique (LORT) with normal saline, air or CO₂. Up to five attempts were occasionally necessary. LORT using fluid resulted in more subarachnoidal penetrations than the LORT using air (P < 0.05) which was easy and reliable but produced patchy anaesthesia (‘painful gaps') in 4.2% of patients. CO₂-LORT was as easy and reliable as air-LORT and did not result in painful gaps. Lateral and mid-line insertion routes were equally suitable whatever the level of approach. Twenty-gauge needles, especially Tuohy needles, resulted in significantly less dural punctures in young children. The spread of the local anaesthetic correlated with the volume injected and the height of the epidural approach. Epidural anaesthesia had little haemodynamic effects. Administration of epidural morphine improved the duration of postoperative pain relief but undesirable effects occurred in up to 50% of patients. Low doses of naloxone (2–5 μg?kg^?1.h^?1) counteracted most adverse effects, avoiding urinary retention and delayed apnoea. Anaesthetists and residents without experience in paediatric anaesthesia had a good success rate in performing the techniques (under supervision of an experienced anaesthetist). At the same time, experience in regional anaesthesia would significantly boost the confidence of the anaesthetist in managing such cases. The authors recommend using CO₂ instead of air in the LORT.     

Hyperbaric vs. isobaric bupivacaine for spinal anaesthesia for elective caesarean section: a Cochrane systematic review

Both isobaric and hyperbaric bupivacaine have been used for spinal anaesthesia for elective caesarean section, but it is not clear if one is better than the other. The primary objective of this systematic review was to determine the effectiveness and safety of hyperbaric bupivacaine compared with isobaric bupivacaine administered during spinal anaesthesia for elective caesarean section. We included 10 studies with 614 subjects in the analysis. There was no evidence of differences either in the risk of conversion to general anaesthesia, with a relative risk (95%CI) of 0.33 (0.09–1.17) (very low quality of evidence), or in the need for supplemental analgesia, the relative risk (95%CI) being 0.61 (0.26–1.41) (very low quality of evidence). There was also no evidence of a difference in the use of ephedrine, the amount of ephedrine used, nausea and vomiting, or headache. Hyperbaric bupivacaine took less time to reach a sensory block height of T4, with a mean difference (95%CI) of ?1.06 min (?1.80 to ?0.31). Due to the rarity of some outcomes, dose variability, use of adjuvant drugs and spinal technique used, future clinical trials should look into using adequate sample size to investigate the primary outcome of the need for supplemental analgesia.     

布比卡因等比重腰麻用于妇科腹腔镜手术

目的 探讨布比卡因等比重腰麻用于妇科腹腔镜手术的可行性。方法 妇科腹腔镜手术59例，ASAⅠ、Ⅱ级，分为布比卡因等比重腰麻（isobaric spinal anesthesia，ISA）组35例，全麻（general anesthesia，GA）组24例，观察ISA组气腹前后阻滞平面的变化及术中口述疼痛评分，监测两组的BP、HR，SpO2、PEICO2、Pa—CO2等生命体征，比较两组术后恶心呕吐的发生率及手术时间。结果 ISA组C02气腹使阻滞平面上升2～4个节段，气腹引起轻～中度疼痛，随阻滞平面上升，疼痛消失或减轻；ISA组腰麻后BP、HR下降，但大部分不需升压药、阿托品，GA组Bp、HR稳定；ISA组有2例患者术中SpO2〈90％，GA组术中SpO2≥98％；两组气腹后PETCO2、PaCO2保持稳定；GA组术后恶心呕吐的发生率高于ISA组，两组手术时间相同。结论 布比卡因等比重腰麻操作简单、起效快、不良反应少，可用于妇科腹腔镜手术。     

利多卡因加左旋布比卡因或布比卡因混合液用于臂丛阻滞的效果比较

目的:比较0.25%左旋布比卡因或0.25%布比卡因与利多卡因1∶1混合液用于臂丛阻滞的麻醉效果和并发症。方法:ASAⅠ～Ⅱ级病人60例,随机分两组行臂丛阻滞,LB组使用左旋布比卡因+利多卡因混合液,B组使用布比卡因+利多卡因混合液。观察两组的感觉阻滞起效时间、阻滞完全时间、麻醉效果优良率、镇痛维持时间、不良反应及麻醉过程中生命体征的变化。结果:两组患者感觉阻滞起效时间及镇痛维持时间LB组明显长于B组(P<0.05);阻滞完全时间、麻醉效果优良率及不良反应发生以及对循环的影响均相似(P>0.05)。结论:利多卡因+左旋布比卡因混合液用于臂丛神经阻滞更具有选择性而且安全有效。     

Epidural ropivacaine – where are the benefits? A prospective,randomized, double‐blind trial in patients with retropubic prostatectomy

BACKGROUND: In comparison with bupivacaine, ropivacaine exhibits comparable anaesthetic effects but with less motor impairment and systemic toxicity. However, the analgesic potency may differ. For example, ropivacaine during obstetric epidural analgesia provides an approximately 40% lower analgesic potency than bupivacaine. Equal visual analogue pain scores require significantly higher dosages of ropivacaine, and general statements about a favourable benefit-risk profile relative to that of bupivacaine may therefore have limited clinical impact. We addressed this topic in a male pain model by evaluating the analgesic efficacy of epidural ropivacaine 0.2% vs. bupivacaine 0.125% after retropubic prostatectomy. METHODS: Forty patients scheduled for retropubic prostatectomy were randomly assigned to two groups (20 patients per group). In a double-blind prospective design, patient-controlled lumbar epidural analgesia was provided by ropivacaine 0.2% in the ropivacaine group and by bupivacaine 0.125% in the bupivacaine group. The primary endpoint was the total amount of local anaesthetic consumption. The secondary endpoints were the numeric rating scale scores for rest and dynamic pain and the degree of motor impairment. RESULTS: Ropivacaine consumption was 60% higher (mean +/- standard deviation, 1372.5 +/- 108.3 mg) than that of bupivacaine (852 +/- 75.2 mg) (P < 0.001). There were no significant differences in the numeric rating scale scores and motor impairment. CONCLUSIONS: In male patients, lumbar epidural administration of ropivacaine 0.2% after retropubic prostatectomy does not appear to provide benefits over bupivacaine 0.125%. Moreover, in view of the significantly higher drug requirements, general statements focusing on the favourable therapeutic index of ropivacaine may require critical analysis, at least during epidural administration.