罗哌卡因与布比卡因硬膜外阻滞用于产科麻醉的效果及母体和胎儿血药浓度变化的比较

目的 比较罗哌卡因和布比卡因硬膜外阻滞用于产科麻醉的效果,及在母体中血药浓度的变化及经胎盘转运的情况。方法18例择期行宫产手术的足月单胎孕妇,随机分为两组,分别用0.75％罗哌卡因(R组)或0.5％布比卡因(B组)行硬外阻滞。观察感觉和运动阻滞情况、血压的变化、新生儿脐静脉血气和Apgar、NACS评分。并用高效液相色谱法测定了母体和胎儿的血浆药物浓度。结果 两组产归感觉和运动阻滞的起效时问和持续时间、最高阻滞平面、低血压的发生率、新生儿血气和Apgar、NACS评分都无显著差别。R组和B组母体血浆药物浓度在15～30min内达高峰,分别为(613±90)ng/ml和(512±63)ng/ml,脐静脉/母体静脉血药浓度比(UV/MV)分别为0.42=0.12和0.48±0.15。结论0.75％罗哌卡因和0.5％布比卡因硬膜外腔阻滞用于剖宫产手术时,都能获得满意的临床效果;两药经胎盘的转运比率相似;母体和胎儿血浆药物浓度远低于可致毒性反应的浓度,且罗哌卡因的安全范围大于布比卡因。     

患者硬膜外注射不同浓度左旋布比卡因的药代动力学

目的 探讨患者硬膜外注射不同浓度左旋布比卡因的药代动力学.方法 择期行结肠癌根治术、经腹或腹会阴直肠癌根治术患者20例,ASA Ⅰ或Ⅱ级,年龄35～59岁,随机分为0.75%左旋布比卡因组(Ⅰ组)和0.5%左旋布比卡因组(Ⅱ组),每组10例.麻醉方法为腰段硬膜外阻滞联合全麻.经L1,2硬膜外穿刺成功后,分别经2 min注入0.75%或0.5%左旋布比卡因2 mg/kg.硬膜外注药结束后30 min内记录感觉和运动阻滞效果,记录不良反应发生情况.于注药后即刻、注药后10、20、30、45、60、90、120、210、300、420、540、660和840 min时取中心静脉血3 ml,采用高效液相色谱法测定血浆左旋布比卡因浓度,绘制血浆左旋布比卡因浓度-时间曲线,计算2组药代动力学参数.结果 2组血浆左旋布比卡因浓度-时间曲线均符合二房室开放模型;2组药代动力学参数比较差异均无统计学意义(P＞0.05).结论 0.75%和0.5%左旋布比卡因2mg/kg腰段硬膜外阻滞安全性高,血浆药物浓度-时间曲线均符合二房室开放模型,两者药代动力学特性无差异.     

布比卡因加入肾上腺素作产科腰段硬膜外镇痛的安全性和有效性

作者为了研究布比卡因加入肾上腺素作腰段硬膜外镇痛对产妇和新生儿的影响,选择32例正常产妇进行观察。监测包括宫缩、胎儿心率和节律、产妇心率、血压。产妇取左侧卧位于L_(3-4)间隙穿刺,向头端留置硬膜外导管2cm。随机分组:Ⅰ组(n=16)用加入1:30万肾上腺素的0.5％布比卡因;Ⅱ组(n=16)用未加肾上腺素的0.5％布比卡因。注射试验量的局麻药2ml后若无蛛网膜下腔阻滞的迹象,再追加局麻药使镇痛平面达胸_(10)。观察每次追加局麻药的镇痛持续时间,各产程持续时间。产妇收缩压低于100托或降低幅度大于30托为低血压,通过加快输液和静注麻黄硷进行处理。产妇于注药10分钟后和婴儿娩出时采静脉血测定血浆局麻药浓度。婴儿娩出后采脐动,静脉血测定血浆局麻药浓度和酸碱状态。并于规定时间进行Apgar评分和神经学及适应能力评分(NACS,满分为40分)。     

年龄因素对患者硬膜外注射左旋布比卡因药效学和药代动力学的影响

目的 探讨年龄因素对患者硬膜外注射左旋布比卡因药效学和药代动力学的影响.方法 择期拟行下肢手术患者45例,年龄30～72岁,体重52～83 ks,ASA Ⅰ或Ⅱ级,按不同年龄分为3组:Ⅰ组(≤45岁)、Ⅱ组(46～64岁)和Ⅲ组(>64岁),每组15例,均采用腰段硬膜外麻醉,左旋布比卡因(7.5 mg/ml)用量1.8 mg/kg(含肾上腺素5 μg/ml).经L1,2硬膜外穿刺成功后,注射试验量0.5%左旋布比卡因3 ml,3 min后注射剩余量0.75%左旋布比卡因.硬膜外注药后记录感觉和运动阻滞效果及不良反应的发生情况;每组随机选择9例,于注药后即刻、注药后10、20、30、45、60、90、120、180、240、360、480、840、和1 440 min时采用高效液相色谱法测定血浆左旋布比卡因浓度,绘制血浆左旋布比卡因浓度-时间曲线,计算3组药代动力学参数.结果 与Ⅰ组比较,Ⅲ组最高感觉阻滞平面高,感觉和运动阻滞维持时间长,(P<0.05);各组麻醉效果优良率均达100%;各组左旋布比卡因的血浆药物浓度-时间曲线均符合二房室开放模型;硬膜外注药后1 440 min时Ⅱ组和Ⅲ组左旋布比卡因血药浓度高于Ⅰ组(P<0.05);Ⅱ组和Ⅲ组左旋布比卡因消除半衰期明显长于Ⅰ组,Ⅲ组明显长于Ⅱ组(P<0.05).结论 不同年龄患者硬膜外注射0.75%左旋布比卡因1.8 mg/kg安全有效;随年龄增加,感觉阻滞平面升高、感觉和运动阻滞恢复时间延长,药物代谢明显减慢.     

不同浓度罗哌卡因腰麻剖宫产胎儿娩出时母体和胎儿脐血浓度的观察

目的通过高效液相色谱法检测胎儿娩出时脐静脉血、母体静脉血罗哌卡因血药浓度,明确药物胎盘转移情况。方法择期行剖宫产术产妇60例,随机均分成H组(0.5%罗哌卡因10mg)和L组(0.375%罗哌卡因10mg)。胎儿取出后立即抽取胎儿脐静脉血与母体静脉血各3ml,应用高效液相色谱法检测罗哌卡因血药浓度。结果本方法得线性方程Y=0.2803X-0.0022,r=0.9993,罗哌卡因质量浓度为0.025～2.400mg/L范围内呈良好的线性关系,最低检测浓度为0.015mg/L,方法回收率95%～110%(n=5)。胎儿娩出时两组母体静脉血罗哌卡因浓度明显高于脐静脉血(P<0.01)。结论本研究建立的高效液相色谱法操作简便,能够测定罗哌卡因血药浓度。罗哌卡因注入蛛网膜下腔后可在母体静脉血与脐静脉血中检出,蛛网膜下腔罗哌卡因浓度不影响其在母体静脉血与脐静脉血中浓度。     

分娩镇痛时硬膜外左旋布比卡因运动阻滞的半数有效浓度

目的 确定分娩镇痛时硬膜外左旋布比卡因运动阻滞的半数有效浓度(EC50).方法 30例ASAI级初产妇,在第一产程宫颈开至2～3 cm时,L2,3硬膜外间隙穿刺,注射负荷量左旋布比卡因10ml,第1例产妇的左旋布比卡因浓度为0.5%,应用序贯法确定下一例产妇的药物浓度,相邻浓度比值为0.95.注药后30 min采用改良Bromage评分法评价下肢运动阻滞程度.结果 左旋布比卡因运动阻滞的EC50为0.562%,95%可信区间为0.542%～0.584%.结论 分娩镇痛时第一产程硬膜外左旋布比卡因(10 ml)运动阻滞的EC50为0.562%,95%可信区间为0.542%～0.584%.     

剖宫产术中异丙酚对新生儿的影响及其胎盘转移

目的 探讨剖宫产术中异丙酚对新生儿的影响及其胎盘转移情况.方法 拟行剖宫产术的足月初产妇60例,ASA Ⅰ或Ⅱ级,年龄23～31岁,体重59～89kg,身高156～169 cm,随机分为2组(n=30):全麻组(G组)和硬膜外麻醉组(E组).G组静脉注射异丙酚2 mg/kg和琥珀胆碱2 mg/kg快速诱导气管插管,行机械通气,局麻辅助下开始手术.胎儿娩出结扎脐带后立即抽取脐静脉(UV)、脐动脉(UA)血样各5 ml,经足背动脉取母体动脉(MA)血样5 ml,采用高效液相色谱法测定血浆异丙酚浓度(CUV、CUA和CMA);E组经L_(1,2)行硬膜外麻醉,给予2%利多卡因11～17 ml,控制感觉阻滞平面上界为T6～8.于入室5 min(T_0),切皮即刻(T_1)、新生儿娩出(T_2)和手术结束(T_3)时记录心率(HR)、脉搏血氧饱和度(SpO_2)和平均动脉压(MAP);记录分娩时间和给药结束到钳夹脐动脉、静脉的时间;胎儿娩出后1、5 min时行Apgar评分.结果 G组给药结束到钳夹脐动、静脉的时间短于E组(P<0.05),两组新生儿Apgar评分、各时点HR、SpO_2和MAP比较差异无统计学意义(P>0.05),两组均未见新生儿呼吸抑制发生,G组术后随访均未发生术中知晓.CMA、CUV和CUA分别为(1.4±0.4)、(0.86±0.25)、(0.70±0.22)μg/ml,CUV/CMA和CUA/CUV分别为0.61±0.11和0.80±0.10.结论 静脉注射异丙酚2 mg/kg用于剖宫产术麻醉效果满意,虽然易通过胎盘,且在胎儿体内代谢慢,但并未对新生儿产生不良影响.     

剖宫产术前病人静脉注射磷酸肌酸钠对胎儿血糖的影响

目的 评价剖宫产术前病人静脉注射磷酸肌酸钠对胎儿血糖的影响.方法 择期行剖宫产术病人60例,ASA Ⅰ或Ⅱ级,年龄22～36岁,随机分为2组(n=30),磷酸肌酸钠组(P组)麻醉前10 min静脉注射磷酸肌酸钠1g,生理盐水对照组(C组)给予生理盐水20 ml.两组采用脊椎-硬膜外联合穿刺针进行穿刺,经L2,3间隙行蛛网膜下腔穿刺成功后,注射0.75%布比卡因1.0～1.2 ml.记录蛛网膜下腔注药后至胎儿娩出时病人低血压和心动过速的发生情况.娩出后1、5 min时进行Apgar评分.娩出时采集脐动脉血样,测定血糖和心肌钙蛋白I(cTnl)浓度.结果 C组病人低血压与心动过速的发生率分别为60%和50%,P组分别为20%和10%,均低于C组(P＜0.05).与C组比较,P组Apgar评分差异无统计学意义(P＞0.05),血糖升高,cTnI降低(P＜0.05).结论 剖宫产术前病人静脉注射磷酸肌酸钠1 g可预防胎儿血糖水平的降低,有利于预防分娩时胎儿心肌损伤.     

剖宫产术患者瑞芬太尼辅助用药对新生儿的影响及其胎盘转移

目的 探讨剖宫产术患者瑞芬太尼辅助用药对新生儿的影响及其胎盘转移情况.方法 择期足月剖宫产术患者40例,初产,ASA Ⅰ级,年龄26～32岁,体重70～90 kg,随机分为2组(n=20),对照组(C组)和瑞芬太尼组(R组).于L3-4间隙穿刺行脊椎-硬膜外联合阻滞,控制阻滞平面上界T6-T8.R组靶控输注瑞芬太尼,血浆靶浓度1.5 ng/ml,C组按瑞芬太尼的血浆靶控模式和靶浓度输注生理盐水,血样采集完毕时停止输注.于入室平静5 min(T0)、切皮(T1)、胎儿娩出(T2)、子宫修补(T3)和关腹(T4)时记录MAP、HR、分钟通气量(MV)、呼吸频率(RR>、警觉,镇静评分(OAA/S评分);记录T0时和消毒前胎心率(FHR)、子宫切开到胎儿娩出时间(分娩时间)、新生儿体重、新生儿1、5 minApgar评分、1、24 h新生儿神经行为评分(NBNA)和患者不良反应发生情况.胎儿娩出后3 min内分别取脐动脉血(UA)、脐静脉血(UV)各2 ml,于足背动脉取母体动脉血(MA)2 ml,行血气分析,测定瑞芬太尼血浆浓度.结果 与C组和T0时比较,R组T1,2时OAMS评分降低(P<0.05).两组间MAP、HR、MV、RR、分娩时间、FHR、血气分析指标、新生儿体重、Apgar评分和NBNA评分的比较差异无统计学意义(P>0.05),且均在正常范围内.胎儿娩出时MA、UV及UA中瑞芬太尼血浆浓度分别为(0.85±0.31)、(0.57±0.12)、(0.22±0.09) ng/ml,CUV/CMA为0.67±0.41,CUA/CUV为0.39±0.08.结论 靶控输注瑞芬太尼(血浆靶浓度1.5 ng/ml)时,尽管瑞芬太尼可迅速进行胎盘转移,但进入胎儿体内后,可迅速被代谢或重分布,因而对新生儿无不良影响.     

老年患者左旋布比卡因硬膜外运动阻滞的半数有效浓度

目的 研究老年和青壮年患者左旋布比卡因硬膜外运动阻滞的半数有效浓度(EC50).方法 60例下肢或下腹部择期手术患者分成老年组(A组,≥70岁)和青壮年组(Y组,<70岁),每组30例.硬膜外穿刺置管后注入15 ml不同浓度的左旋布比卡因:每组第一位患者左旋布比卡因浓度均定为0.375%,其后各患者所用浓度按序贯法进行选择,浓度变化梯度定为0.025%.以改良Bromage评分法判断运动阻滞程度,计算硬膜外左旋布比卡因运动阻滞的EC50.结果 A组左旋布比卡因硬膜外运动阻滞的EC50为0.349%(95%可信区间:0.327%～0.373%),显著低于Y组的0.453%(95%可信区间:0.424%～0.484%)(P<0.01).结论 与青壮年患者相比,老年患者左旋布比卡因硬膜外运动阻滞的EC50明显降低.     

Comparison between general,spinal, epidural,and combined spinal-epidural anesthesia for cesarean delivery: a network meta-analysis

BackgroundThis study is a network meta-analysis to compare maternal and fetal outcomes associated with four different anesthetic techniques for cesarean delivery.MethodsAn arm-based, random-effects frequentist network meta-analysis was performed. A random effect model was selected considering deviance information criteria. Randomized trials reporting the following outcomes were included: Apgar score at 1- or 5-min; umbilical arterial and venous pH; umbilical arterial pH <7.2; and neonatal score at 2–4 hours. Loop-specific heterogeneity was evaluated by risk of odds ratio and τ². Quality of evidence was assessed using the GRADE approach.ResultsData from 46 randomized trials including 3689 women contributed to the study. There were significant differences in Apgar score ≤6 at 1 min between spinal versus general anesthesia (odds ratio 0.27, 95% confidence interval [CI] 0.13 to 0.55: moderate quality evidence) and Apgar scores at 1- and 5-min, favoring spinal anesthesia. Umbilical venous pH associated with epidural anesthesia was significantly higher than that with general anesthesia (mean difference 0.010, 95% CI 0.001 to 0.020: moderate quality evidence) or spinal anesthesia. Spinal anesthesia was ranked best for Apgar score ≤6 at 1-min (SUCRA=89.8), Apgar score at 1-min (SUCRA=80.4) and 5-min (SUCRA=90.5). Epidural anesthesia was ranked highest for umbilical venous pH (SUCRA=87.4) and neonatal score (SUCRA=79.3).ConclusionsSpinal and epidural anesthesia were ranked high regarding Apgar scores and epidural anesthesia was ranked high regarding umbilical venous pH, but the results were based on small heterogeneous studies with high or unclear risks of bias.     

硬膜外阻滞剖宫产术中测定脐带血气值的临床意义

目的：探讨硬膜外阻滞剖宫产术中测定脐带血气值的临床意义。方法：选３２６例在硬膜外阻滞下行剖宫产术的病例，测定新生儿脐动脉血气值，并评定新生儿１分钟Ａｐｇａｒ评分。根据不同临床状态将所有病人分为八组行统计分析。结果：１分钟Ａｐｇａｒ评分与脐动脉血气值无显著相关。在存在影响母儿血气因素时，发生脐动脉酸血症及低氧血症的病例显著增加。结论：产妇及其胎儿健康、麻醉手术经过顺利的病例可不检测脐带血气值。在存有     

Pharmacokinetics, placental transfer, and neonatal effects of vecuronium and pancuronium administered during cesarean section

Vecuronium and pancuronium were compared for placental transfer, pharmacokinetic variables, and neonatal effects during cesarean section under general anesthesia. Eighteen women underwent rapid-sequence intravenous induction using d-tubocurarine, succinylcholine, thiopental, and oxygen. Immediately after tracheal intubation, an intravenous injection of vecuronium (n = 11) or pancuronium (n = 7), 0.04 mg/kg, was given. Maternal venous blood samples were obtained before induction and at frequent intervals for 4 h after administration of vecuronium or pancuronium. Also, maternal venous and umbilical-cord arterial and venous blood samples were obtained at delivery. To describe placental transfer and maternal pharmacokinetics of the drugs, serum drug concentrations were determined using single-ion-monitoring mass spectrometry. The Apgar score and Neurologic and Adaptive Capacity Score (NACS) were used to evaluate neonatal condition. Both drugs crossed the placenta, as demonstrated by low concentrations of vecuronium (8.5-26.4 ng/ml) or pancuronium (12.2-34.2 ng/ml) found in umbilical venous blood. At delivery, the ratio of the drug concentration in umbilical venous blood to that in maternal venous blood was 0.11 +/- 0.02 for vecuronium and 0.19 +/- 0.03 for pancuronium. Vecuronium had a more rapid clearance (6.4 +/- 0.4 ml X kg-1 X min-1, mean +/- SE) and a shorter elimination half-life (36 +/- 1.8 min) than pancuronium (3.0 +/- 0.1 ml X kg-1 X min-1 and 72 +/- 6 min, respectively). No other pharmacokinetic differences were found between the drugs. Neonatal outcome was not affected adversely by either muscle relaxant, as assessed by Apgar scores and NACSs . The short duration of action, the minimal placental transfer, and the apparent lack of clinical neuromuscular effects on the newborn suggest that vecuronium should be a useful muscle relaxant for cesarean section.     

Maternal and neonatal effects of adding epidural sufentanil to 0.5% bupivacaine for cesarean delivery.

STUDY OBJECTIVE: To determine the maternal and fetal effects of the addition of epidural sufentanil to 0.5% bupivacaine for cesarean delivery. DESIGN: Randomized, double-blind, prospective study. SETTING: University Hospitals, Katholieke Universiteit Leuven, Leuven, Belgium. PATIENTS: Sixty women at term scheduled for elective cesarean section, all of whom had elected epidural anesthesia. INTERVENTIONS: The 60 women were divided into three groups of 20, with each group receiving a different 1 ml study solution: saline (control) or sufentanil 20 micrograms or sufentanil 30 micrograms added to 0.5% bupivacaine and epinephrine (1:200,000). MEASUREMENTS AND MAIN RESULTS: In the mother, the quality of anesthesia, the duration of postoperative analgesia, the volume of anesthetic, and the frequency of side effects were examined. The neonates were evaluated at 5 and 10 minutes after birth by Apgar scores and between 60 and 120 minutes after birth by both the screening test developed by Prechtl and the Neurological and Adaptive Capacity Scoring System. Immediately after delivery, maternal and umbilical vein blood were drawn and assayed for sufentanil levels. Adding sufentanil significantly improved the quality of anesthesia without depressing the neurobehavioral status of the baby. CONCLUSION: The epidural injection of sufentanil added to 0.5% bupivacaine with epinephrine improved the quality of anesthesia during elective cesarean section without jeopardizing the safety of the baby.     

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine in preeclampsia

The pharmacokinetics and maternal and neonatal effects of epidural lidocaine were compared in ten preeclamptic and five normotensive women undergoing cesarean section at 36-40 weeks of gestation. Lumbar epidural anesthesia was achieved using 15-20 ml of 2% lidocaine without epinephrine. Serial venous samples for lidocaine levels were drawn from all the mothers during the procedure and up to 6 hr after the initial injection. Umbilical venous and arterial samples were drawn at delivery for measurement of neonatal acid-base status and lidocaine levels. There were no significant differences between normotensive and preeclamptic patients in the total dose of lidocaine, peak maternal plasma concentration, volume of distribution, maternal elimination half-life and umbilical vein/maternal vein ratios. The calculated area under the concentration time curve in preeclamptic patients (18.5 +/- 4.7 micrograms X hr X ml-1) was significantly greater than in normotensive mothers (14.1 +/- 1.3 micrograms X hr X ml-1) (P less than 0.02). Total maternal body clearance in preeclamptic patients (24.5 +/- 7.1 L/hr) was significantly lower than in normotensives (31.1 +/- 4.4 L/hr) (P less than 0.05). Neonatal outcome as evaluated by Apgar scores, umbilical arterial and venous blood gas tensions, umbilical vein/maternal vein ratios, and early neonatal neurobehavior scores at 4 hr and 24 hr after birth were similar in the two groups. The results indicate that the total maternal body clearance of lidocaine is prolonged in preeclampsia, and repeated administration of lidocaine can result in higher blood levels than in normotensive parturients.     

剖宫产术患者瑞芬太尼-异丙酚-阿曲库铵复合麻醉的效果

目的 探讨瑞芬太尼-异丙酚-阿曲库铵复合麻醉用于剖宫产术患者的效果.方法 全麻剖宫产术患者40例,ASA Ⅰ或Ⅱ级.麻醉诱导:静脉注射瑞芬太尼1 μg/kg、异丙酚1.5 mg/kg和阿曲库铵0.6 mg/kg,气管插管后行机械通气.麻醉维持:静脉输注瑞芬太尼0.15 μg·kg~(-1)·min~(-1),异丙酚4 mg·kg~(-1)·~(-1),间断静脉注射阿曲库铵0.3 mg/kg.取新生儿脐动脉(UA)血样1 ml行血气分析,取UA、脐静脉(UV)和母体动脉(MA)血样各2 ml,以气相色谱.质谱法测定血浆瑞芬太尼浓度(CUV、CUA和CMA).于气管插管前、气管插管即刻、切皮即刻、拔除气管导管即刻记录血液动力学指标,记录苏醒时间和术者满意情况,术后随访术中知晓情况.行新生儿Apgar评分和神经行为学评分(NBNA).结果 所有患者各时点血液动力学平稳,均在正常范围波动.苏醒时间为(5±4)min,未见术中知晓发生.新生儿UA血气分析结果均在正常范围内.新生儿1、5、10 min Apgar评分均大于7分,NBNA均正常.CUV、CUA和CMA分别为(0.65±0.14)、(0.22±0.09)、(0.86±0.25)ng/ml,CUV/CMA和CUA/CUV分别为0.7±0.4和0.35±0.11.结论 瑞芬太尼-异丙酚-阿曲库铵复合麻醉用于削宫产术患者效果良好,对新生儿无不良影响.     

Zusatz von Fentanyl zur Bupivacain – Periduralanalgesie bei Sectio Caesarea

Epidural anaesthesia for elective caesarean section can have advantages over general anaesthesia. The anaesthesiologist can avoid endotracheal intubation as well as fetal depression following placental transfer of systemic anaesthetics. However, despite reaching an effective blockade preoperatively, intraoperative discomfort and pain may occur during epidural anaesthesia with local anaesthetics alone, necessitating supplemental systemic analgesics or even conversion to general anaesthesia [21]. Addition of epidural fentanyl has been shown to improve onset and quality of perioperative analgesia without evident side effects for mother or newborn [24]. Nevertheless, administration of epidural opioids before cord clamping is still hotly debated, some fearing maternal and or neonatal depression [6, 26]. The aim of the present study was to investigate the quality of analgesia, associated side effects and the resulting maternal and neonatal plasma opiate concentrations after a single preoperative addition of 0.1 mg fentanyl to epidural bupivacaine analgesia in comparison to epidural bupivacaine analgesia alone. Methods. Following governmental and ethics committee approval, 43 elective consenting patients for caesarean section were randomized to receive double-blind injections of either 8 ml 0.5% bupivacaine+0.1 mg fentanyl (B+F group, n=22) or 8 ml 0.5% bupivacaine +2 ml saline (Bup group, n=21) into an epidural catheter. In both groups additional injections of bupivacaine were given to achieve sensory blockade up to T4. Systolic blood pressure, heart and respiratory rates were measured regularly. Quality of intraoperative pain relief was assessed at delivery, uterine eventration, and during uterine and abdominal closure using a visual analogue scale (VAS). The duration of postoperative analgesia was compared between groups, as well as the incidence of nausea, itching or sedation. Similarly, Apgar scores and umbilical arterial and venous blood gas analyses were compared. Fentanyl concentrations were determined in maternal venous blood sampled before and 20 and 40 min after epidural injection and at birth, and in umbilical venous and arterial blood sampled after delivery. Radioimmunoassay analysis was performed from plasma specimens centrifuged and frozen at ?20° C [19]. The statistical level of significance was defined as P<0.05. Results. Groups were comparable regarding age, weight and time of gestation. Total bupivacaine doses and injection to delivery times were similar in both groups. Figure 1 shows that there were 40% more pain-free (VAS=0) patients in the B+F group during uterine eventration and wound closure (P<0.05). Mean postoperative duration of analgesia was significantly longer in the B+F group (382 vs 236 min). The rate of nausea and mild itching was significantly higher in the B+F group. Respiratory depression was never detected in patients or newborns. Small group differences in blood pressure or respiratory rate were inconstant and clinically irrelevant, as were differences in umbilical venous pCO₂. One hundred and twenty-five blood samples were analysed for fentanyl concentrations. The mean fentanyl concentration before epidural injection was not zero, but 0.25 ng/mg (range 0.02–0.32). Maternal concentrations at 20 and 40 min after injection were 0.55 ng/ml (0.12–1.14) and 0.52 ng/ml (0.26–1.04) (Fig. 3). At delivery, mean maternal fentanyl concentration was 0.58 ng/ml (0.14–1.18); mean umbilical arterial and venous concentrations were 0.51 ng/ml (0.04–1.8) and 0.41 ng/ml (0.18–1.2), respectively. Rare results of fentanyl concentrations >1.0 ng/ml correlated neither with sedation, maternal respiratory rate and side effects, nor with Apgar scores and umbilical blood gas values. No Apgar score at 5 min was below 9, and no umbilical pH was below 7.20. Conclusion. We conclude that preoperative epidural addition of 0.1 mg fentanyl to 0.5% bupivacaine significantly improves intraoperative pain relief during elective caesarean section and prolongs postoperative analgesia. This important advantage of fentanyl is associated with an increased incidence of nausea and mild itching. No clinically significant fentanyl-associated depression of vigilance could be detected in the mother or newborn. The resulting plasma fentanyl concentrations are within safe limits. When administered epidurally and preoperatively for caesarean section, maternal plasma levels of fentanyl do not decrease significantly until birth. In the radioimmunoassay an unknown substance cross-reacts like fentanyl.     

腰麻-硬膜外联合麻醉对剖宫产母婴肾素-血管紧张素-醛固酮系统的影响

目的 研究腰麻－硬膜外联合麻醉（CSEA）对剖宫产母婴肾素－血管紧张素－醋固酮系统（RAAS）的影响。方法 将60例ASA Ⅰ级行择期剖宫产的健康产妇随机分为硬膜外麻醉组（EA组，n＝30）和CSEA组（n＝30)。分别于注射局麻药前(T0)、切皮后即刻（T1）、胎儿晚出后即刻（T2）、术毕即刻（T3）和术后24h（T4）取母体静脉血和胎儿娩出后胎儿脐动、静脉血测定血清素活性（PRA）、血管紧张素Ⅱ（AT-Ⅱ）和醛固酮（ALD）浓度；评定麻醉效果，记录痛觉阻滞平面达T7水平的时间，注射局麻药至胎儿娩出时间（I－DI）及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分。结果 两组术中SP、DP、HR、SpO2的变化及新生儿娩出1min、5min的Apgar评分差异无显著性（P＞0.05）。同EA组相比，CSEA组麻醉起效时间明显缩短（P＜0.01）。两组母体于T1、T2、T4的PRA、AT－Ⅱ、ALD值均比T0、T3值明显降低（P＜0.01），胎儿脐动、静脉血中三者值差异不明显，但明显低于母体T0、T3值（P＜0.01）。结论 CSEA用于剖宫产手术时，只要运用得当，不会对母婴AAS产生不良影响。