不同椎间隙穿刺留管术后硬膜外持续泵注低浓度罗哌卡因镇痛效应的比较

目的 研究妇科手术后不同椎间隙留管硬膜外持续泵注罗哌卡因镇痛效应。方法 选择经腹子宫全切术的病人80例(ASAⅠ-Ⅱ级)随机分为四组,A1、A2组术后硬膜外留管位置为T_(11-12);B1组、B2组则为L(2-3);均采用双泵镇痛法双盲对照观察(n=20)。四组第一泵为硬膜外0.2％罗哌卡因4ml/h;第二泵中A1组、B1组以0.08％氯诺昔康静脉病人自控镇痛(PCA)辅助,其PCA设置为0.8mg/次,锁定时间为5min;A2组与B2组以0.1％吗啡静脉PCA,其设置为1mg/次,锁定时间为5min。结果 四组24h硬膜外罗哌卡因使用剂量为192mg;A1组、A2组静脉氯诺昔康和吗啡PCA的剂量分别为(3.9±2.8)mg和(4.6±3.5)mg,而B1组、B2组则为(7.7±2.5)mg和(7.8±2.4)mg,T_(11-12)硬膜外留管(A1组、A2组)静脉辅助镇痛药量明显减少(P<0.05)。四组相同时间段内VAS、BCS、Bromage评分及D1/D2比值均无统计学差异。结论 妇科手术后T_(11-12)硬膜外留管0.2％罗哌卡因硬膜外持续泵注(4ml/h)比L_(2-3)留管的镇痛效应更强,且静脉PCA辅助药量更少。     

罗哌卡因联合曲马多术后硬膜外镇痛疗效观察

我院应用罗哌卡因联合曲马多术后硬膜外镇痛,并就镇痛效果、并发症与罗哌卡因联合吗啡进行比较。资料与方法一般资料选择腹部手术40例,男26例,女14例,年龄(40.2±7.2)岁,ASAⅠ或Ⅱ级,随机均分为两组,Ⅰ组行罗哌卡因联合曲马多硬膜外镇痛,Ⅱ组行罗哌卡因联合吗啡硬膜外镇痛。方法两组患者均术前肌注苯巴比妥钠0.1g、阿托品0.5mg。于T8～12或L1～2间行硬膜外腔穿刺置管,术中硬膜外腔间断注入1.5%利多卡因 0.2%地卡因维持麻醉。术毕Ⅰ组患者硬膜外注入0.25%罗哌卡因5ml加曲马多100mg,接镇痛泵,内含0.125%罗哌卡因100ml、曲马多800mg、氟哌利…     

剖宫产术后患者左旋布比卡因、罗哌卡因与布比卡因混合芬太尼硬膜外镇痛的效应

目的 比较左旋布比卡因、罗哌卡因和布比卡因复合芬太尼用于剖宫产术后硬膜外镇痛的效果和副作用。方法 采用随机双盲法,将51例择期行剖宫产术的足月、单胎孕妇分为三组:左旋布比卡因组(L组)、罗哌卡因组(R组)和布比卡因组(B组),每组17例。术后分别采用0.125％左旋布比卡因、0.2％罗哌卡因及0.125％布比卡因复合小剂量芬太尼(2μg·ml-1)行病人自控硬膜外镇痛(PCEA)。观察各组术后48 h内镇痛效果、运动阻滞程度变化以及恶心呕吐、尿潴留等副作用的发生率。结果 三组产妇术后视觉模拟评分、改良Bromage评分比较差异均无显著性(P>0.05)。三组产妇对PCEA的非常满意率差异无显著性(L组88.2％,R组76.5％,B组81.3％,P>0.05)。三组不良反应发生率及排气时间差异无显著性(P>0.05)。结论 0.125％左旋布比卡因混合芬太尼(2μg·ml-1)用于产科术后硬膜外镇痛可获得满意的镇痛效果且无明显毒副作用。     

罗哌卡因硬膜外持续输注下氯诺昔康PCIA的临床效应

目的 研究硬膜外持续输注罗哌卡因期间氯诺昔康静脉PCA的临床效应和不良反应,并以吗啡对照比较。方法 选择60例(ASAⅠ～Ⅱ)妇科经腹子宫全切手术病人,随机分为L组与M组,双盲观察,均采用双泵行PCA治疗。其PCA设置为Bolus 1ml/次,锁定时间为5min,1h限量12ml。镇痛效果和副作用评定:(1)采用视觉模拟评分(VAS),0为无痛、10为剧痛。(2)BCS舒适评分。(3)病人对PCA总体印象评分。(4)记录可能出现的并发症和不良反应。结果 两组病人的一般情况相似,24h硬膜外罗哌卡因使用剂量均为192mg,L组与M组未按压PCA泵的病人各为5例(21.7％),静脉PCA用药剂量分别为(3.4±2.8)mg(L组)和(4.7±3.5)mg(M组),两药用量比值为1:1.4(P>0.05);相同时间段内两组间VAS、BCS、Bromage评分及D1/D2比值均无统计学差异。结论0.2％罗哌卡因硬膜外持续输注(4ml/h)能明显减少静脉PCA用量,新型非甾体类抗炎药氯诺昔康与吗啡静脉用药效价相似,但氯诺昔康对病人恶心呕吐的不良反应具有明显减少的优点。     

罗哌卡因用于可行走的硬膜外术后镇痛的临床研究

目的:对比观察罗哌卡因用于可行走的硬膜外术后镇痛的理想浓度和效果。方法:200例妇产料手术,随机分为两组:布比卡因组(B组)和罗哌卡因组(L组)。术后镇痛均采用硬膜外自控镇疯(PCEA),镇痛液为0.075％布比卡因和0.075％罗哌卡因分别复合芬太尼0.2mg、氟哌啶5mg。术后第4、8、12、24、36、48h记录镇痛评分(VAS)、运动神经阻滞评分、不良反应及生命体征。结果:两组生命体征均稳定,VAS评分无明显差异。运动功能评分,L组明显优于B组,差异有显著性意义(P<0.05)。结论;0.075％罗哌卡因用于术后镇痛效果好,运动神经阻滞轻微,是可行走的硬膜外术后镇痛的理想浓度。     

舒芬太尼复合罗哌卡因用于下腹部手术后硬膜外自控镇痛

目的 观察舒芬太尼复合罗哌卡因用于下腹部手术后患者硬膜外自控镇痛(patient-controlled epidural analgesia,PCEA)的效果.方法 下腹部择期手术120例,年龄28 ～66岁,ASA分级Ⅰ、Ⅱ级,应用随机数字表法分为3组(每组40例):0.5 mg/L舒芬太尼复合0.2％罗哌卡因组(Ⅰ组)、5 mg/L芬太尼复合0.2％罗哌卡因组(Ⅱ组)和0.2％罗哌卡因组(Ⅲ组).所有患者术后镇痛均采用PCEA模式,观察镇痛后4、8、16、24、48 h的MAP、HR、VAS评分和Ramsay镇静评分(ramsay sedationscore,RSS)情况,并记录48 h内镇痛泵总按压次数以及恶心、呕吐、皮肤瘙痒及呼吸抑制的发生率.结果 各时点Ⅰ组VAS评分[(1.4±0.4)、(1.6±0.5)、(1.5±0.4)、(1.6±0.3)、(1.3±0.3)分]和Ⅱ组VAS评分[(1.5±0.6)、(1.6±0.4)、(1.7±0.6)、(1.5±0.4)、(1.4±0.6)分]明显低于Ⅲ组[(2.1±0.7)、(2.4±0.6)、(2.4±0.5)、(2.3±0.7)、(2.2±0.8)分](P＜0.05);在8、16、24 h,Ⅰ组RSS[(2.4±0.6)、(2.1±0.9)、(2.4±0.5)分]高于Ⅱ组[(1.4±0.7)、(1.6±0.6)、(1.6±0.4)分]和Ⅲ组RSS[(1.7±0.6)、(1.4±0.3)、(1.6±0.6)](P＜0.05);Ⅰ组和Ⅱ组镇痛泵总按压次数与Ⅲ组比较,差异有统计学意义(分别为3、4、18次,P＜0.05);Ⅰ组和Ⅱ组恶心呕吐的发生率高于Ⅲ组(分别为15％、12.5％、0,P＜0.05);3组皆未发生呼吸抑制.结论 0.5 mg/L舒芬太尼配伍0.2％罗哌卡因用于下腹部手术后PCEA效果确切,且副作用发生率低.     

硬膜外甲磺酸罗比卡因复合吗啡应用于妇科术后镇痛的观察

目的比较硬膜外甲磺酸罗比卡因与盐酸罗比卡因复合吗啡用于妇科术后镇痛的临床效果和安全性。方法40例择期在硬膜外麻醉下行经腹子宫全切或子宫肌瘤摘除手术患者,随机分为两组,观察组(n=40)采用0·238%甲磺酸罗比卡因(含0·002mg/ml吗啡);对照组(n=40)采用0·2%盐酸罗比卡因(含0·002mg/ml吗啡)。观察术后15min、2、4、8、24、48h两组患者的视觉模拟评分(VAS)、镇静评分、下肢运动神经阻滞情况及副作用的发生率。结果在各时点两组患者的VAS、镇静评分、下肢运动神经阻滞情况及副作用的发生率差异均无显著意义。结论硬膜外甲磺酸罗比卡因与盐酸罗比卡因复合吗啡术后镇痛具有相似的临床效果和安全性。     

持续鞘内吗啡联合布比卡因用于中重度晚期癌痛患者的疗效和安全性

目的评估持续鞘内吗啡联合布比卡因用于中重度晚期癌痛患者的疗效和安全性。方法 42例中重度晚期癌痛患者,随机分为单纯鞘内吗啡组(A组)与吗啡联合布比卡因组(B组),每组21例。植入鞘内导管外接电子PCA泵实施持续鞘内镇痛,分别给予A组0.2mg/ml吗啡,B组0.2mg/ml吗啡+0.75mg/ml布比卡因混合液起始按口服吗啡转换剂量持续鞘内泵入+单次冲击量(24h背景量的1/10,锁定时间1h);记录患者术前、术后1周、2周、1月的静息及运动VSA疼痛评分、吗啡用量、便秘症状评分及WHOQOL-BREF生活质量评分,并观察镇痛后头痛、恶心呕吐、尿潴留、皮肤瘙痒、下肢麻木、运动阻滞不良反应的发生率。结果两组患者鞘内镇痛后静息VAS评分及便秘症状评分均显著下降(P<0.01),两组间差异无统计学意义。B组鞘内镇痛后运动VAS评分低于A组(P<0.05),每日吗啡用量低于A组(P<0.01),WHOQOL-BREF生理领域评分高于A组(P<0.05)。两组均有少数患者出现恶心呕吐、皮肤瘙痒、尿潴留、下肢麻木及运动阻滞,但差异无统计学意义。结论持续鞘内吗啡联合布比卡因用于中重度癌痛效果确切,运动痛及生活质量改善优于单纯鞘内吗啡。     

左布比卡因复合右美托咪定在分娩镇痛中的应用及对母儿的影响

目的 研究左布比卡因复合右美托咪定(dexmedetomidine,Dex)在分娩镇痛中的应用及对母儿的影响. 方法 120例单胎、头位、初产妇,采用随机数字表法分为两组(每组60例),观察组(A组)应用左布比卡因复合Dex,对照组(B组)应用左布比卡因复合舒芬太尼,两组均采用硬膜外麻醉方式.产妇行硬膜外穿刺,两组分别给予0.1％左布比卡因+0.5 mg/L Dex复合液和0.1％左布比卡因+0.5 mg/L舒芬太尼复合液各5 ml.连接泵镇痛,泵速设置为8ml/h,患者自控镇痛(patient controlled analgesia,PCA)追加5 ml/次,锁定15 min.观察两组产妇生命体征、VAS评分、Bromage评分、Ramsay评分、产程、产后出血及新生儿Apgar评分. 结果 与麻醉前(T0)比较,麻醉后30 min(Tt)两组产妇MAP[A组,(81.8±4.7) mmHg(1 mmHg=0.133 kPa)比(93.0±6.2) mmHg;B组,(86.3±5.4)mmHg比(93.8±7.0) mmHg]、HR[A组,(70±10)次/min比(90±10)次/min;B组,(76±8)次/min比(88±8)次/min]均降低(P＜0.05).VAS评分,在T0、T1、活跃期1 h(T2)、第二产程1 h(T3)时,A组分别为(8.6±1.1)、(1.3±0.7)、(1.7±0.6)、(3.5±0.7)分,B组分别为(8.8±1.2)、(3.0±0.3)、(3.0±0.5)、(3.2±0.8)分,两组差异有统计学意义(P＜0.05).Ramsay评分在T1～T3时点,B组[(3.0±0.2)、(4.0±0.3)、(4.0±0.1)分]与A组[(2.0±0.3)、(2.0±0.2)、(2.0±0.1)分]比较,差异有统计学意义(P＜0.05).两组Bromage评分、产程时间、妊娠结局、产后出血及新生儿Apgar评分比较,差异无统计学意义(P＞0.05). 结论 左布比卡因复合Dex用于分娩镇痛安全、有效、舒适.     

国产罗哌卡因用于乳腺癌术后硬膜外镇痛

目的比较国产罗哌卡因(康博宁,GL)和进口罗哌卡因(耐乐品,JL)复合吗啡用于乳腺癌术后硬膜外自控镇痛的临床效果。方法选择50例择期行乳腺癌根治术的患者,连续硬膜外麻醉,术后随机均分为两组,GL组:0.15%GL复合吗啡(30μg/ml);JL组:0.15%JL复合吗啡(30μg/ml)。观察患者术后48h内的镇痛效果及不良反应发生率。结果两组VAS、镇痛治疗总体印象评分差异无统计学意义,两组不良反应发生率差异亦无统计学意义。结论0.15%GL和JL用于乳腺癌术后镇痛,效果均满意,均无明显不良反应。     

Pharmacokinetics of 0.2% ropivacaine and 0.2% bupivacaine following caudal blocks in children

BACKGROUND: Ropivacaine is the first S-enantiomer aminoamide local anaesthetic in clinical use, and has been found to be less toxic than bupivacaine. Caudal ropivacine has been shown to cause less motor blockade and longer duration of analgesia in the postoperative period than bupivacaine in children. Plasma levels of ropivacaine and bupivacaine have not been previously compared in children. This study was undertaken to compare the total venous plasma concentrations of similar doses of ropivacaine and bupivacaine following caudal administration. METHODS: Blood samples were obtained to determine the total venous plasma levels of the used local anaesthetic in 30 children, aged 2.3-8.7 years, ASA I, given 1 ml x kg of either 0.2% ropivacaine or 0.2% bupivacaine in a prospective, randomised manner. RESULTS: There were no differences in the individual peak plasma concentrations achieved. Time to the measured peak plasma concentration was significantly shorter in the bupivacaine group. The plasma concentrations of bupivacaine were significantly lower than for ropivacaine at 60, 90 and 120 min after the block. CONCLUSION: Absorption and tissue distribution of ropivacaine is slower than for bupivacaine following caudal administration in children.     

Comparison of ropivacaine 0.1% and 0.2% with bupivacaine 0.2% for single-shot caudal anaesthesia in children

We compared analgesic efficacy and degree of motor block induced by ropivacaine 0.1% (R 0.1) and 0.2% (R 0.2) vs. bupivacaine 0.2% (B 0. 2) after caudal anaesthesia in children. Total and free plasma concentrations were measured after caudal injection. Duration of caudal analgesia (median/range) was significantly shorter in group R 0.1 (1.7 h/0.2-6 h) than in group R 0.2 (4.5 h/1.7-6 h) or group B 0. 2 (4 h/1-6 h) (P<0.05). Motor block in the first 2 h postoperatively was significantly less for both ropivacaine groups compared with bupivacaine (P<0.05). Peak plasma concentrations after ropivacaine 0.2% were higher and protein binding lower than after bupivacaine 0.2% (P<0.05). We conclude that caudal analgesia with ropivacaine 0.1% is less effective and of shorter duration than that of ropivacaine 0.2%, whereas ropivacaine 0.2% provides pain relief similar to bupivacaine 0.2%. Motor block in the early postoperative period is less with ropivacaine than with bupivacaine.     

Caudal 0.2% ropivacaine is less effective during surgery than 0.2% levobupivacaine and 0.2% bupivacaine: a double-blind, randomized, controlled trial

BACKGROUND: We hypothesized that without the analgesic effects of volatile anesthetics, caudal 0.20% ropivacaine would be less effective during surgical stimulation than 0.20% bupivacaine or 0.20% levobupivacaine. This trial was designed to examine whether the combination of a caudal block with 0.20% ropivacaine and i.v. anesthesia resulted in reduced analgesic efficacy during surgery compared with caudal 0.20% levobupivacaine or 0.20% bupivacaine in children. METHODS: Ninety ASA I-II children between 1 and 7 years old, scheduled for inguinal hernia repair or orchidopexy under propofol anesthesia were randomized to receive a caudal block with 1 ml x kg(-1) of 0.2% bupivacaine, 0.2% ropivacaine or 0.2% levobupivacaine. The primary outcome measure of the study was the clinical efficacy of the caudal block during surgery. Secondary outcome measures were postoperative pain relief and residual motor blockade. RESULTS: Four children were excluded and 86 were analyzed. The proportion of children with effective caudal block during surgery was significantly higher in children receiving levobupivacaine (26/28) or bupivacaine (27/29) compared with patients receiving ropivacaine (21/29) (P = 0.03). There were no significant differences among groups in the analgesic onset time (P = 0.1), incidence of residual motor blockade (P = 0.4), number of patients requiring analgesia after operation or in the time from caudal injection to the first administration of analgesic medication (P = 0.3). CONCLUSIONS: Combined with propofol anesthesia, 0.2% levobupivacaine and 0.2% bupivacaine are more effective than 0.2% ropivacaine for caudal use in children undergoing inguinal hernia repair or orchidopexy.     

Comparison of bupivacaine 0.2% and ropivacaine 0.2% combined with fentanyl for epidural analgesia during labour

BACKGROUND AND OBJECTIVE: Recent clinical studies comparing ropivacaine 0.25% with bupivacaine 0.25% reported not only comparable analgesia, but also comparable motor block for epidural analgesia during labour. An opioid can be combined with local anaesthetic to reduce the incidence of side-effects and to improve analgesia for the relief of labour pain. The purpose of the study was to evaluate the effects of epidural bupivacaine 0.2% compared with ropivacaine 0.2% combined with fentanyl for the initiation and maintenance of analgesia during labour and delivery. METHODS: Sixty labouring nulliparous women were randomly allocated to receive either bupivacaine 0.2% with fentanyl 2 microg mL(-1) (B/F), or ropivacaine 0.2% with fentanyl 2 microg mL(-1) (R/F). For the initiation of epidural analgesia, 8 mL of the study solution was administered. Supplemental analgesia was obtained with 4 mL of the study solution according to parturients' needs when their pain was > or = 4 on a visual analogue scale. Analgesia, hourly local anaesthetic use, motor block, patient satisfaction and side-effects between groups were evaluated during labour and at delivery. RESULTS: Sixty patients were enrolled and 53 completed the study. No differences in verbal pain scores, hourly local anaesthetic use or patient satisfaction between groups were observed. However, motor block was observed in 10 patients in the B/F group whereas only two patients had motor block in the R/F group (P < 0.05). The incidence of instrumental delivery was also higher in the B/F group than in the R/F group (P < 0.05). CONCLUSIONS: The results suggest that epidural bupivacaine 0.2% and ropivacaine 0.2% combined with fentanyl produced equivalent analgesia for pain relief during labour and delivery. It is concluded that ropivacaine 0.2% combined with fentanyl 2 microg mL(-1) provided effective analgesia with significantly less motor block and need for an instrumental delivery than a bupivacaine/fentanyl combination at the same concentrations during labour and delivery.     

Caudal anesthesia for minor pediatric surgery: a prospective randomized comparison of ropivacaine 0.2% vs levobupivacaine 0.2%

BACKGROUND: Previous published data comparing ropivacaine 0.2% with levobupivacaine 0.25% have suggested that ropivacaine might be associated with less early postoperative motor blockade compared with levobupivacaine. The aim of the present study was to further investigate this issue comparing equal concentrations (0.2%) of ropivacaine and levobupivacaine in children undergoing minor subumbilical surgery. METHODS: Following induction of a standardized anesthetic, patients (1-7 years) were randomized in a double-blind manner to receive a caudal block with either ropivacaine 0.2% (group R, n=30) or levobupivacaine 0.2% (group L, n=30), total volume 1 ml.kg-1. Motor blockade (modified Bromage scale; primary end-point) and analgesia [Children and Infants Postoperative Pain Scale (CHIPPS) score] were assessed at predetermined time points during the first 24-postoperative hours. RESULTS: Motor blockade was only registered during the first postoperative hour with no significant differences between the groups (group R n=5, group L n=8). Postoperative CHIPPS scores were almost identical in both groups with only seven and six patients requiring supplemental analgesia (CHIPPS score>or=4) in the R and L groups, respectively. CONCLUSIONS: A 0.2% concentrations of ropivacaine or levobupivacaine are clinically very similar with regard to postoperative analgesia and unwanted postoperative motor blockade in children undergoing minor subumbilical surgery.     

Levobupivacaine 0.2% or 0.125% for continuous sciatic nerve block: a prospective, randomized, double-blind comparison with 0.2% ropivacaine

In 60 patients receiving elective hallux valgus repair, we compared the efficacy of continuous popliteal sciatic nerve block produced with 0.2% ropivacaine (n = 20), 0.2% levobupivacaine (n = 20), or 0.125% levobupivacaine (n = 20) infused with a patient-controlled system starting 3 h after a 30-mL bolus of the 0.5% concentration of the study drug and for 48 h (baseline infusion rate, 6 mL/h; incremental dose, 2 mL; lockout time, 15 min; maximum incremental doses per hour, 3). No differences were reported in the intraoperative efficacy of the nerve block. The degree of pain was similar in the three groups throughout the study period, both at rest and during motion. Total consumption of local anesthetic solution during the first 24 h was 148 mL (range, 144-228 mL) with 0.2% ropivacaine, 150 mL (range, 144-200 mL) with 0.2% levobupivacaine, and 148 mL (range, 144-164 mL) with 0.125% levobupivacaine (P = 0.59). The volume of local anesthetic consumed during the second postoperative day was 150 mL (range, 144-164 mL) with 0.2% ropivacaine, 154 mL (range, 144-176 mL) with 0.2% levobupivacaine, and 151 mL (range, 144-216 mL) with 0.125% levobupivacaine (P = 0.14). A smaller proportion of patients receiving 0.2% levobupivacaine showed complete recovery of foot motor function as compared with 0.2% ropivacaine and 0.125% levobupivacaine, both at 24 h (35% vs 85% and 95%; P = 0.0005) and at 48 h (60% vs 100% and 100%; P = 0.001). We conclude that sciatic infusion with both 0.125% and 0.2% levobupivacaine provides adequate postoperative analgesia after hallux valgus repair, clinically similar to that provided by 0.2% ropivacaine; however, the 0.125% concentration is preferred if early mobilization of the operated foot is required.     

Comparison of 0.125% bupivacaine and 0.2% ropivacaine in obstetric analgesia

This comparative study of low doses of ropivacaine was conducted in order to identify the most effective form of analgesia during labour with the aid of supplementary low doses of fentanyl and clonidine. 60 ASA I and II parturient primipares who had asked for epidural analgesia were randomly assigned to two groups. Group R was given 5-7 ml 0.2% ropivacaine and Group B 0.125% bupivacaine with both groups receiving 75 ng clonidine and 50 ng fentanyl with their first bolus of local anaesthetic. The parameters measured included the speed and spread of the sensory blockade and the scale of any motor blockade. The material haemodynamics and VAS pain relief scores were also measured at 30-minute intervals during labour and all side-effects (nausea, vomiting, localised or generalised itching, headache etc) were also monitored. Apgar anaesthetics and other drugs was decided on the basis of the VAS score (a further dose was given to women with a VAS of > 3-4). The study was completed by a telephone interview 6 months after delivery and the data were analysed using the Student's t-test and the chi 2 test. The analgesic effect was satisfactory in both groups and no statistically significant differences were found between the two groups under most of the headings analysed, apart from the top-up doses needed to maintain adequate analgesia. The average time between the first VAS to parturition was 292 mns in Group B and 267 mns in Groups R. Top-up doses of local anaesthetic (2.35 vs 5.05) came on average to 15.8 ml in Group B compared to 24.1 ml in Group R. There were 20% Caesarian sections in Group R and 13.8% in Group B. Optimum analgesia was achieved in Group R, the level of analgesia was insufficient or barely sufficient in 3.3% of cases. There was no Apgar score < 7 in either group. It was therefore concluded that both bupivacaine and ropivacaine offer excellent analgesia during labour and have no significant side effects on mothers or babies.     

Alkalinization and precipitation characteristics of 0.2% ropivacaine

BACKGROUND AND OBJECTIVES: Alkalinization of local anesthetics has been used to increase the speed of onset of nerve blocks. However, alkalinization of local anesthetic solutions may cause precipitation, thereby decreasing bioavailability and anesthetic activity. Alkalinization of ropivacaine has not been described. This laboratory study assessed the alkalinization and precipitation characteristics of ropivacaine. METHODS: Aliquots (2 mL) of commercially available ropivacaine (Naropin, 0.2%; Astra Pharmaceutical, Westborough, MA) were alkalinized with increasing amounts (0.01, 0.02, 0.04 mL) of sodium bicarbonate (8.4%) and immediately monitored for pH change and onset of visible precipitation at room temperature. We then alkalinized ropivacaine with sodium bicarbonate and measured the amount of precipitate that accumulated after various incubation times. RESULTS: The pH of ropivacaine increases with the addition of small amounts of bicarbonate. The calculated percentage of nonionized ropivacaine increased from 0.3% to greater than 30% with alkalinization from pH of 5.51 to 7.63. Drug loss to precipitation increased with higher doses of bicarbonate, reaching 25% to 30% of the total ropivacaine. Even with a low dose of bicarbonate (0.1 mL bicarbonate/20 mL ropivacaine), precipitation increased with time of incubation, reaching a plateau at 20 minutes. CONCLUSIONS: A laboratory evaluation that establishes the alkalinization characteristics of ropivacaine is a prerequisite for designing a clinical study of alkalinized ropivacaine. In our experiment, low doses of bicarbonate produced significant increases in the proportion of nonionized ropivacaine with only modest precipitation. There would be a low likelihood of substantial drug precipitation if the mixture was administered within 5 to 10 minutes after alkalinization. These results indicate that alkalinized ropivacaine should not be used for infusions and that ropivacaine should not be alkalinized until just before use.     

Comparison of ropivacaine 0.2% and 0.25% with lidocaine 0.5% for intravenous regional anesthesia

Study ObjectiveTo compare the anesthetic effects of two different concentrations and doses of ropivacaine (0.2% and 0.25%) with those of a conventional dose of lidocaine 0.5%.DesignProspective, randomized, double-blinded, clinical investigation.SettingLarge metropolitan university hospital.Patients66 adult ASA physical status I and II patients undergoing forearm and hand surgery.InterventionsPatients were randomly allocated to three groups to receive intravenous regional anesthesia (IVRA). Study groups were: ropivacaine 0.2% (Group I, n = 22), ropivacaine 0.25% (Group II, n = 22), and lidocaine 0.5% (Group III, n = 22).MeasurementsTourniquet tolerance times and regression of sensory analgesia were noted. Verbal numerical pain scores (VNS), cumulative analgesic consumption, and side effects were recorded during surgery and postanesthesia care unit (PACU). Time to first pain medication intake and number of patients receiving analgesics in the PACU were recorded.Main ResultsAdditional tolerance times for the distal tourniquet were significantly higher in the ropivacaine 0.25% group than the other two groups. Regression of sensory anesthesia was fastest in the lidocaine group. During the PACU stay, VNSs were significantly lower in the first 20 minutes in the ropivacaine groups than the lidocaine group. Time to first intake of pain medication in the PACU was soonest in the lidocaine group. The number of patients given analgesics in the PACU was highest in the lidocaine group. The number of patients taking > two tablets of tramadol was significantly lowest in the ropivacaine 0.25% group. No serious side effects were observed in any study group.ConclusionLonger tolerance times for the distal tourniquet, prolonged analgesia after tourniquet release, and lower analgesic requirements postoperatively make ropivacaine 0.2% and 0.25% an alternative to lidocaine for IVRA.