Systemic toxic effects of local anaesthetics

Local anaesthetics are widely used in the provision of local/regional anaesthesia and the management of acute and chronic pain. Their mechanism of action temporarily inhibits voltage gated sodium channels in neuronal plasma membranes. Local anaesthetic systemic toxicity (LAST) is a serious yet largely preventable complication that can occur by any of the multiple routes of administration. LAST predominantly affects the central nervous and cardiovascular systems. Awareness of LAST and vigilance during administration of local anaesthetics may help in early recognition and successful management of the toxicity. Intralipid emulsion (ILE) infusions have been successfully used in reversing local anaesthetic-induced cardiotoxicity. Since 2007 in the UK, ILE infusion has been incorporated into the safety guidelines for management of LAST.     

Effect of Ketamine Added to Ropivacaine in Nerve Block for Postoperative Pain Management in Patients Undergoing Anterior Cruciate Ligament Reconstruction: A Randomized Trial

PurposeNerve blocks are commonly used as a part of multimodal pain relief. It was previously shown that ketamine could enhance the analgesic effect of local anesthetics in nerve blocks. A literature review on adding ketamine to local anesthetics for ameliorating analgesia revealed inconsistencies in analgesic efficiency and safety. This prospective, randomized, double-blind trial was performed to evaluate the antinociceptive effect of mixing ketamine with local anesthetics in a combined femoral and sciatic nerve block (CFSNB) during anterior cruciate ligament (ACL) reconstruction.MethodsSeventy-six patients undergoing preoperative ultrasound-guided CFSNB in ACL reconstruction were enrolled. Patients were randomly assigned to 3 groups: Group RNK received perineural administration of 40-mg ketamine plus 0.375% ropivacaine in 40-mL volume; Group RIK received 40 mL of 0.375% ropivacaine, as well as IV ketamine 40 mg; and Group R received 40 mL of 0.375% ropivacaine. Pain scores were recorded. AUC was calculated based on the pain scores at different times. Duration of CFSNB, postoperative analgesic demand, time to first analgesic demand, and adverse events were also examined.FindingsPerineural ketamine decreased pain scores 20 and 24 h' postoperatively, as well as lowered AUC values (all, P = 0.001). Group RNK had a prolonged time to first analgesic request (P = 0.014), inhibited rebound pain (P = 0.001), and increased satisfactory score at 48 h’ postsurgery (P = 0.001). Perineural ketamine prolonged the duration of sensory block (P = 0.001) with no effect on early mobilization. There were no significant differences between Group R and Group RIK in terms of postoperative pain scores, AUC of different time intervals (P = 0.832 or more), and time to first rescue analgesics (P = 0.585). Compared with the 2 other groups, IV ketamine had a higher incidence of hallucination after operations.ImplicationsPerineural ketamine added to the ropivacaine-enhanced analgesic efficacy of CFSNB with less rebound pain compared with the IV ketamine and control groups. IV ketamine had no effect in potentiating analgesia when a conventional multimodal approach was used in the study. Chinese Clinical Trial Registry: ChiCTR1900023867.     

罗哌卡因联合地塞米松连续股神经阻滞在人工全膝关节置换术术后镇痛中的应用

目的比较罗哌卡因联合地塞米松连续股神经阻滞（连续股神经阻滞）与单纯罗哌卡因连续股神经阻滞用于人工全膝关节置换术（TKA）患者术后镇痛效果。方法选取本院及开平市中心医院40例拟行TKA患者随机分成对照组和试验,每组20例,所有患者术后在B超下行连续股神经阻滞麻醉。对照组镇痛药物为2.5 g/L罗哌卡因150 mL;试验组镇痛药物为2.5 g/L罗哌卡因和0.1 g/L 地塞米松混合液150 mL。记录所有患者不同时间点静息状态疼痛视觉模拟（VAS）评分,主、被动功能训练VAS评分,吗啡用量,主动屈曲关节角度以及麻醉相关不良反应。结果试验组6、12、24、48、72 h静息状态VAS评分均低于对照组,差异有统计学意义（P<0.05）。试验组术后24、48、72 h主、被动功能训练VAS评分均低于对照组（P<0.05）。试验组与对照组患者术后6 h后各时间段及72 h总吗啡用量均低于对照组（P<0.05）。试验组患者术后24、48、72 h患肢主动关节屈曲角度均大于对照组（P<0.05）。对照组麻醉相关不良反应发生率为30%,试验组为15%,两组患者麻醉相关不良反应发生率差异无统计学意义（P>0.05）。结论与单纯罗哌卡因相比,罗哌卡因联合地塞米松连续股神经阻滞可加强TKA患者的术后镇痛作用,提高TKA患者术后康复锻炼效果,减少阿片类药物的使用,且并发症发生率低,值得推广。     

盐酸丁卡因粉剂用于开胸手术后硬膜外镇痛

研究盐酸丁卡因粉剂用于开胸肺叶切除术后硬膜外麻醉病人自控镇痛的镇痛效果及其对呼吸和循环功能的影响。43例全麻下开胸肺叶切除术病人，随机分为盐酸丁卡因(22例)和盐酸罗哌卡因(21例)两组。两组病人术后均使用病人自控硬膜外镇痛泵，分别采用0．15％丁卡因与0．3％罗哌卡因行硬膜外镇痛48h。镇痛泵设定为单次注射模式：单次剂量6mL，锁定时间1h。采用视觉模拟评分(VAS)评估镇痛效果。术前及术后每日测定用力肺活量(FVC)，第一秒用力呼气量(FEV1.0)，第一秒用力呼气量占用力肺活量的百分率(FEV1.0/FVC)及呼气流量峰值(PEF)。监测并记录每次注药前后的血流动力学指标。结果表明，硬膜外单次注射局麻药后两组病人VAS均显著降低。两组间术后FEV1.0/FVC和PEF改变率无显著性差异。给药后两组病人心率、血压、血氧饱和度的改变率亦无显著性差异。开胸术后使用0．15％丁卡因行病人自控硬膜外镇痛的镇痛效果及对呼吸和循环功能的影响与0．3％罗哌卡因相似，未见严重不良反应发生。     

低浓度罗哌卡因硬膜外麻醉用于经尿道前列腺电切术的麻醉处理

目的：探讨低浓度罗哌卡因用于经尿道前列腺电切术患者的麻醉处理及效果。方法择期行经尿道前列腺电切术并硬膜外穿刺置管成功的老年患者63例。结果2例患者Ramsay镇静评分1级,35例患者Ramsay镇静评分3级,26例患者Ramsay镇静评分2级,术后随访患者对手术和麻醉无不良记忆。讨论低浓度的罗哌卡因用于硬膜外麻醉对呼吸循环功能影响小,安全且镇痛效果明确,值得在临床上应用推广。     

罗哌卡因复合咪唑安定在小儿骶管阻滞麻醉中的临床研究

目的：观察罗哌卡因复合咪唑安定在小儿骶管阻滞麻醉中的有效性和安全性。方法：40例1～6岁行下腹部、会阴部及下肢手术患儿，随机双盲分成布比卡因（2．5mg／kg）对照组，罗哌卡因低、中、高（2．5、3．5、5．0mg／kg）剂量组。采用七氟醚诱导吸入麻醉加骶管阻滞罗哌卡因，复合咪唑安定（0．2mg／kg）。结果：在一定剂量范围内，罗哌卡因复合咪唑安定对舒张压、平均动脉压的影响小；术中心率、动脉血氧饱和度有轻度下降，但均在生理范围内；高、中剂量组术后镇痛持续时间类似布比卡因，低剂量短于布比卡因。除个别患儿在术中有牵拉反应和术后呕吐外，其余均未见明显不良反应。结论：罗哌卡因骶管阻滞复合咪唑安定在小儿麻醉中对患儿血液动力学影响小、可延长镇痛时间，且无明显不良反应。     

低浓度罗哌卡因复合舒芬太尼用于上肢手术后镇痛的效果

目的:观察低浓度罗哌卡因复合舒芬太尼用于上肢手术后的镇痛效果。方法:上肢骨折切开复位术后60例患者随机分为低浓度(0.125%)罗哌卡因复合舒芬太尼留置针自控镇痛(试验组,n=29)与舒芬太尼静脉自控镇痛(对照组,n=31),分别于术后4,8,12,24 h观察VAS疼痛评分和VAS满意度评分,24 h按键次数和24 h药液消耗量以及不良反应。结果:试验组VAS疼痛评分显著低于对照组,VAS满意度评分显著高于对照组,按键次数、24 h消耗量和不良反应发生率均显著低于对照组(P<0.05)。结论:低浓度罗哌卡因用于上肢术后镇痛安全有效。     

产程活跃期患者自控硬膜外分娩镇痛的应用及对母儿结局的影响

目的研究产程活跃期患者自控硬膜外分娩镇痛（patient-ontrolled pidural nalgesia，PCEA）的应用效果及对母儿结局的影响。方法对2004年2月至2006年2月要求分娩镇痛的190例单胎、足月临产的初产妇，采用前瞻性研究方法，将其随机分为两组：镇痛Ⅰ组采用0．2％罗哌卡因（98例），镇痛Ⅱ组采用0．1%布比卡因（92例），均辅以芬太尼2μg／ml，首次负荷量为10ml，采用电子镇痛泵调节维持给药量为5ml／h，宫口开全后停用麻醉剂，选取同期未采用任何镇痛方法分娩的100例为对照组（分组征得患者本人的知情同意）。结果镇痛Ⅰ组、镇痛Ⅱ组的孕妇分娩镇痛效果均良好，两组比较，差异无显著意义（P〉0．05）。分娩镇痛能缩短产程活跃期时间，降低剖宫产率，与对照组比较，差异有显著意义（P〈0．05）。镇痛Ⅰ组与镇痛Ⅱ组相比，使用阴道器械的助产率低（P〈0．05），对产妇产后出血无影响（P〉0．05），对胎儿和新生儿无不良影响。结论患者自控硬膜外分娩镇痛对母亲及胎儿安全有效，罗哌卡因不影响子宫收缩力和其他产力，更有利于阴道分娩。     

硬膜外持续泵注罗哌卡因阻滞的临床研究

目的:探讨硬膜外持续泵注新型长效酰胺类局麻药罗哌卡因的可行性.方法:将60例拟行妇产科手术的患者随机分为0.75%罗哌卡因组持续泵入给药组(A组)和0.75%罗哌卡因组间断给药组(B组).两组均在L2～3硬膜外穿刺成功并给予实验量后,A组(30例)硬膜外注入0.75%罗哌卡因12mL,然后以6mL/h的速度用微泵持续输入;B组(30例)注入0.75%罗哌卡因15mL,在80min后时追加6mL.分别测定麻醉前及硬膜外给药后的平均动脉压(MAP)、心率(HR);首次注药后至手术结束时针刺皮肤测阻滞平面,同时记录改良Bromage评分,术中肌松质量由手术者评定(手术者为同一组人),分为很满意、满意和不满意;记录术中麻黄素使用情况.结果:B组在90min左右时血压出现明显下降,与A组比较差异有统计学意义(P＜0.05),A组术中麻黄素使用病例数较少(P＜0.05).两组间皮肤阻滞平面、Bromage评分和术中肌松情况比较差异无统计学意义(P＞0.05).结论:硬膜外微泵持续泵入罗哌卡因的给药方法既可以达到间断给药法同样的麻醉效果,又避免了间断法造成血压大幅波动的缺点,是一种较为安全的给药方法.     

Comparison of epidural pain treatment with sufentanil-ropivacaine infusion with and without epinephrine in children

BACKGROUND: Epidural analgesia provides outstanding pain relief after surgery, but it is also associated with numerous adverse effects. In order to improve postoperative pain management in children we determined whether the use of epinephrine added to epidural sufentanil-ropivacaine infusion reduced drug requirements, the intensity and duration of postoperative pain and the incidence and severity of adverse effects. METHODS: A prospective, randomized, double blind, parallel group study design was used in 61 children. The children were given continuous epidural sufentanil-ropivacaine infusion either with (n=32) or without (n=29) epinephrine for postoperative analgesia. Intravenous ketoprofen, a non-steroid anti-inflammatory drug, was used for all children, and epidural ropivacaine was used for rescue analgesia. The drug consumption, intensity of pain at rest and during activity, and all adverse effects were recorded. RESULTS: : The need for sufentanil (P=0.001) and ropivacaine (P=0.006) was significantly lower in the with-epinephrine group than in the without-epinephrine group. The mean duration of epidural infusion (62 h) was similar in both groups. Four children in the without-epinephrine group were noticed to have a low oxygen saturation (SpO2<90%), and in one child a low respiratory rate (8 breaths min-1). The incidence of pruritus was higher in the without-epinephrine group (P=0.026). CONCLUSION: Both infusions provided effective pain relief, and epinephrine as an adjuvant to continuous epidural sufentanil-ropivacaine infusion seems to be useful in children.