Safety and efficacy of epinephrine added to bupivacaine for lumbar epidural analgesia in obstetrics

The effects of epidural bupivacaine with and without 1:300,000 epinephrine on uterine activity, progress of labor, fetal heart rate, maternal blood pressure and heart rate, newborn Apgar scores, neonatal acid-base status, and Neurologic and Adaptive Capacity Scoring System (NACS) were compared in 32 parturients during labor and delivery. Patients in group I (n = 16) received 0.5% bupivacaine with 1:300,000 epinephrine and those in group II (n = 16) received 0.5% bupivacaine alone. Addition of epinephrine to bupivacaine had no significant effects on uterine activity, duration of first or second stages of labor, fetal heart rate and variability, or the incidence of abnormal fetal heart rate patterns. Maternal hypotension occurred less frequently in group I than in group II patients (P less than 0.05). Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I than in group II (186.8 +/- 11.6 vs 85.3 +/- 6.1 (mean +/- SEM) min, P less than 0.001). It is concluded that adding epinephrine to bupivacaine during epidural anesthesia in the normal parturient has no adverse effects on either mother, fetus, neonate, or the progress of labor; and that it significantly prolongs the duration of anesthesia and decreases the incidence of maternal hypotension.     

Comparative maternal, fetal, and neonatal effects of chloroprocaine with and without epinephrine for epidural anesthesia in obstetrics

The effects of epidural chloroprocaine with and without 1:200,000 epinephrine during labor and delivery on uterine activity, progress of labor, fetal heart rate, maternal blood pressure, newborn Apgar scores, neonatal acid-base status, and the Neurologic and Adaptive Capacity Scoring System (NACS) were compared in 28 parturients. Patients in group I (n = 14) received 2% chloroprocaine with 1:200,000 epinephrine and patients in group II (n = 14) received 2% plain chloroprocaine. Addition of epinephrine to chloroprocaine had no significant effects on uterine activity, duration of first or second stages of labor, or fetal heart parameters. Apgar scores, neonatal acid-base status, and the NACS were equally good in the two groups. Duration of analgesia was significantly longer in group I than in group II patients (76 +/- 3.8 vs 42.9 +/- 1 min, P less than 0.001). We conclude that addition of epinephrine to chloroprocaine during epidural anesthesia in the normal parturient has no adverse effects on mother, fetus, neonate, or the progress of labor and that it significantly prolongs the duration of anesthesia.     

Continuous infusion epidural analgesia in parturients receiving bupivacaine, chloroprocaine, or lidocaine--maternal, fetal, and neonatal effects

The effects of epidural analgesia for labor and delivery using a continuous infusion technique on fetal heart rate, uterine activity, maternal blood pressure, Apgar scores, neonatal acid-base status, and the Neurologic and Adaptive Capacity Scoring System were studied in 61 parturients. Group I (n = 23) received initial test and therapeutic doses of 2 and 6 ml of 0.5% bupivacaine followed by an infusion of 0.125% at a rate of 14 ml/hr. Group II (n = 19) received 2 and 6 ml of 2% chloroprocaine followed by an infusion of 0.75% at a rate of 27 ml/hr. Group III (n = 19) received 2 and 6 ml of 1.5% lidocaine followed by an infusion of 0.75% at a rate of 14 ml/hr. None of the three local anesthetics used had any significant effect on baseline fetal heart rate or uterine activity. In cases in which monitoring of fetal heart rate was both technically satisfactory and continuous, late and variable decelerations in fetal heart rate were seen in 10 of 17, 3 of 18, and 2 of 19 of the fetuses in groups I, II, and III, respectively. The incidence was significantly higher in group I than in groups II or III (P less than 0.05). Apgar scores and neonatal acid-base status were equally good in all three groups. Neurologic and adaptive capacity scores did not differ among the three groups of neonates, nor did any of the neonates in the three groups score lower than a control group of 19 neonates whose mothers did not receive any analgesia or medications for labor and delivery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of standard diluted epinephrine infusion on epidural anesthesia in labor

BACKGROUND AND OBJECTIVES: Epinephrine is used with local anesthetics to prolong the duration of epidural analgesia and decrease the peak plasma concentrations of local anesthetics. However, the duration of labor may be prolonged because epinephrine reduces uterine activity. We designed a prospective, randomized, and doubleblind study to examine the effects of epinephrine infusion on the quality of analgesia and plasma concentration of local anesthetic, as well as the effect on the uteroplacental circulation, duration of the first or second stage of labor, and fetal outcome. METHODS: Twenty-four parturients received continuous epidural bupivacaine 0.125% (8 mL/h) combined either with epinephrine (40 microg/h) (n = 12) or without epinephrine (n = 12) for analgesia during labor. If patients requested additional analgesia, a bolus of 1% or 1.5% lidocaine (6 to 10 mL) was given. RESULTS: Only the plain bupivacaine group required additional lidocaine. However, epinephrine infusion prolonged the median (range) duration of the second stages of labor: 69 (21 to 231) minutes with epinephrine group versus 31 (8 to 99) minutes without epinephrine group (P < .05), and decreased pH in umbilical artery at the time of delivery. Epinephrine infusion did not change the uterine and umbilical blood flow, which were determined as the resistance indices. Changes in the fetal heart rate and Apgar score were also comparable. Epinephrine significantly reduced the umbilical venous to maternal arterial bupivacaine concentration (P < .05). CONCLUSIONS: A standard diluted epinephrine infusion (40 microg/h) into epidural space decreased anesthetic requirements. The possibility of the prolonged duration of labor remains a problem.     

Fetal heart rate after epidural lidocaine and bupivacaine for elective cesarean section

This prospective double-blind study was designed to determine whether the fetal heart rate (FHR) changes that have been reported after epidural administration of bupivacaine and lidocaine during labor are present when larger doses of these drugs are given during elective cesarean section. Prior to inserting an epidural catheter, FHR and maternal vital signs were monitored during a control period in 60 healthy term parturients. Patients were randomly assigned to receive either 0.5% bupivacaine with 0.1 mEq sodium bicarbonate added to each 20 ml (n = 30) or 2% lidocaine with 1:300,000 epinephrine (n = 30). A 3-ml test dose of the study solution was injected via the catheter and was followed by an additional 17 ml, in increments; additional doses were administered as necessary to obtain surgical anesthesia. FHR and maternal vital signs were monitored for at least 20 min and the characteristics of the anesthetic block noted. At delivery, neonatal status was evaluated, and maternal and cord blood samples were obtained for local anesthetic assays and neonatal blood gases. The groups were similar with respect to maternal characteristics, onset of surgical anesthesia, time to delivery, and uterine incision-delivery interval. Maternal blood pressure decreased from control values in both groups (P less than 0.05), but there was no difference between the groups in either the incidence of hypotension or ephedrine requirements. Analysis of FHR tracings by a perinatologist blinded to the study group revealed no changes after anesthesia and no significant differences between the groups at any time in basal FHR, short- or long-term variability, or the incidence of accelerations or decelerations.(ABSTRACT TRUNCATED AT 250 WORDS)     

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.     

程控硬膜外间歇脉冲注入与持续背景输注用于分娩镇痛的比较

目的比较程控硬膜外间歇脉冲注入(programmed intermittent epidural bolus,PIEB)和持续背景输注(CEI)两种模式联合PCEA用于分娩镇痛的临床效果。方法自愿接受分娩镇痛足月、单胎和头位初产妇200例,随机分为两组,每组100例。在宫口扩张2~3 cm时采用硬膜外阻滞行分娩镇痛。PIEB组背景输注剂量为8 ml/h,给药速度为6 ml/min,每小时给药一次;CEI组以8ml/h的速度持续给药。观察产妇镇痛前(T0)、镇痛后10 min(T1)、30 min(T2)、1 h(T3)、2 h(T4)、宫口开全时(T5)、分娩时(T6)、分娩后1 h(T7)BP、VAS评分、改良Bromage评分;PCEA追加次数、罗哌卡因、舒芬太尼的用量、宫缩情况、胎心率、产程时间、镇痛时间、分娩方式、产妇使用催产素、不良反应、新生儿Apgar评分、产妇满意度评分。结果 T4~T6时PIEB组VAS评分明显低于CEI组(P0.01)。PIEB组PCEA追加次数、药物用量明显少于CEI组(P0.05),PIEB组产妇满意度明显高于CEI组(P0.05)。两组产妇的血压、宫缩持续时间和间隔时间、胎心率、产程、镇痛时间、分娩方式、使用催产素比例、不良反应发生率及新生儿Apgar评分差异无统计学意义。结论与采用CEI+PCEA模式比较,PIEB+PCEA模式的PCEA追加率更低、用药量更少、VAS评分更低、产妇的满意度更高,而不良反应并没有增加。     

Effect of epidural epinephrine infusion with bupivacaine on labor pain and mother-fetus outcome in humans

BACKGROUND AND OBJECTIVES: Epinephrine is used with local anesthetics to prolong the duration of epidural analgesia and decrease the peak plasma concentrations of local anesthetics. In the practice of obstetric anesthesia, the utero-placental and fetal effects of epinephrine are controversial issues. We designed a prospective, randomized, and double-blind study to examine the effects of epinephrine infusion on the quality of analgesia and uterine or umbilical blood flows with Doppler ultrasound, as well as the duration of the first or the second stage of labor, and fetal outcome. METHODS: Twenty-eight parturients received continuous epidural bupivacaine 0.25% (4 mL/h) combined either with epinephrine (20 microg/h) (n = 13) or without epinephrine (n = 15) for analgesia during labor. If patients requested additional analgesia, an additional bolus of 1% or 1.5% lidocaine (6 to 10 mL) was administered. RESULTS: The total amount of additional lidocaine was greater in the plain bupivacaine group (130 [0, 280] mg; median [25th, 75th percentile] with P < .05) than in the epinephrine group (0 [0, 60] mg). Epinephrine infusion did not alter the resistance of the uterine and umbilical arteries as measured by resistance index. The duration of the first or second stages of labor did not significantly differ in the 2 groups. Epinephrine infusion did not change the fetal heart rate or the blood gas data in the umbilical artery. CONCLUSIONS: A low-dose epidural infusion of epinephrine decreased anesthetic requirements.     

Epidural lidocaine for cesarean delivery of the distressed fetus

Lidocaine with epinephrine and sodium bicarbonate has a rapid onset of action. We therefore wished to compare its use with that of chloroprocaine for urgent cesarean delivery. Thirty parturients for cesarean section under epidural anesthesia were divided into three groups. Group 1 required elective cesarean section and served as the control group for neonatal lidocaine levels. Groups 2 and 3 had been receiving epidural infusions of 0.125% bupivacaine with epinephrine 1:400,000 and required urgent cesarean section. They were randomized to receive either 1.5% lidocaine with epinephrine or 3% chloroprocaine, both with sodium bicarbonate 2 ml in a total volume of 25 ml. All patients had adequate anesthesia and none required supplementation. The time from completion of injection to the achievement of a T4 sensory level was significantly shorter in the chloroprocaine group (3.1 vs. 4.4 min). There were no differences in Apgar scores or Neurologic and Adaptive Capacity Scores between the lidocaine and chloroprocaine groups. Lidocaine was detectable in maternal serum from four of the urgent cases and all of the elective cases. It was detectable in five neonates from the elective group but none from the emergency group. In parturients with preexisting epidural catheters and a baseline epidural infusion to maintain a T10 sensory level, chloroprocaine is faster in onset than lidocaine, but the difference in this study was only 1.3 min, and both agents provided excellent anesthesia.     

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。     

Lidocaine disposition in mother, fetus, and neonate after spinal anesthesia

Although it is generally believed that concentrations of local anesthetic in maternal plasma do not reach levels that affect the fetus after spinal anesthesia, there are few studies that have measured drug levels in either maternal or neonatal plasma after spinal anesthesia. The purpose of this study was to document the disposition of lidocaine in mother, fetus, and neonate after spinal anesthesia using gas chromatographic/mass spectrometric measurement of lidocaine and two metabolites of lidocaine. Plasma concentration time curves, fetal/maternal ratios, cord artery/cord vein ratios, and neonatal urine levels were determined in ten patients. The results document that lidocaine is present in maternal and neonatal plasma. Mean (+/- SD) maternal plasma levels (0.65 +/- 0.52 micrograms/ml) were significantly lower than those previously reported after epidural anesthesia (2.09 +/- 1.31 micrograms/ml). Fetal/maternal plasma concentration ratios averaged 0.37 +/- 0.2 and mean cord arterial/cord venous ratios 0.5 +/- 6.7. Lidocaine and its metabolites were present in neonatal urine for longer than 36 hr. This study demonstrates that spinal anesthesia with lidocaine results in neonatal exposure to lidocaine.     

Fetal heart rate abnormalities after regional analgesia for labor pain: the effect of intrathecal opioids

BACKGROUND AND OBJECTIVES: Intrathecal opioids used to relieve labor pain have been associated with uterine hyperactivity and nonreassuring fetal heart rate abnormalities. We retrospectively evaluated all charts of singleton, term, vertex-presenting parturients in active labor requesting neuraxial pain relief during a 1-year period for the occurrence of nonreassuring fetal heart rate tracings. METHODS: Three different strategies to relieve labor pain were routinely used in our department: conventional epidural using 10 mL bupivacaine 0.125% and sufentanil 0.75 microg/mL; combined spinal and epidural (CSE) using intrathecal sufentanil (7.5 microg); and CSE using intrathecal bupivacaine (2.5 mg) and sufentanil (1.5 microg). Charts (n = 1,293) were evaluated for nonreassuring fetal heart tracings and uterine hyperactivity as well as for neonatal and labor outcome. RESULTS: Intrathecal sufentanil (7.5 microg) produced significantly more nonreassuring tracings and uterine hyperactivity. However, this did not result in more cesarean deliveries or detrimental neonatal outcome. CONCLUSION: Based on this retrospective analysis, we conclude that intrathecal sufentanil in a dose of 7.5 microg has the potential to result in more nonreassuring fetal heart rate tracings compared with both intrathecal analgesia using a bupivacaine (2.5 mg)/sufentanil (1.5 microg) mixture and epidural analgesia using bupivacaine, sufentanil, and epinephrine. Reg Anesth Pain Med 2001;26:257-262.     

Abnormal echogenic findings detected by transesophageal echocardiography and cardiorespiratory impairment during total knee arthroplasty with tourniquet

BACKGROUND: The minimum local analgesic concentration (MLAC) has been defined as the median effective local analgesic concentration in a 20-ml volume for epidural analgesia in the first stage of labor. The aim of this study was to determine the local anesthetic-sparing efficacy of epidural epinephrine by its effect on the MLAC of bupivacaine. METHODS: In this double-blind, randomized, prospective study, 70 parturients who were at 7 cm or less cervical dilation and who requested epidural analgesia were allocated to one of two groups. After lumbar epidural catheter placement, 20 ml bupivacaine (n = 35) or bupivacaine with epinephrine 1:300,000 (n = 35) was administered. The concentration of bupivacaine was determined by the response of the previous patient in that group to a higher or lower concentration using up-down sequential allocation. Analgesic efficacy was assessed using 100-mm visual analog pain scores, with 10 mm or less within 30 min defined as effective. RESULTS: The MLAC of bupivacaine alone was 0.091% wt/vol (95% confidence interval, 0.081-0.102). The addition of epinephrine 1:300,000 (66.7 microg) resulted in a significant reduction (P < 0.01) in the MLAC of bupivacaine to 0.065% wt/vol (95% confidence interval, 0.047-0.083). The lowest maternal blood pressure was significantly lower in the bupivacaine-epinephrine group (P = 0.03). There were statistically significant reductions in fetal heart rate (P = 0.011) in the bupivacaine-epinephrine group that were not clinically significant. CONCLUSIONS: The addition of epidural epinephrine 1:300,000 (66 microg) resulted in a significant 29% reduction in the MLAC of bupivacaine. Coincident reductions in fetal heart rate and maternal blood pressure were also observed that were not clinically significant.     

Epidural anesthesia in the normotensive pregnant ewe: Effects on uterine blood flow and fetal acid-base status.

Lumbar epidural anesthesia was administered to 12 normotensive pregnant ewes. Blood pressure was maintained by intravenous fluid infusion. Six ewes received anesthesia with 1.5 per cent 2-chloroprocaine with 1:100,000 epinephrine and the remaining six received 1.5 per cent 2-chloroprocaine without epinephrine. The sensory level of anesthesia was between the umbilicus and xiphisternum. Except for a transient 14 per cent decrease in uterine blood flow in the ewes receiving 2-chloroprocaine with epinephrine, uterine blood flow remained near control values and was sufficient at all times to maintain stable fetal acid-base and blood gas values. Provided blood pressure and uterine blood flow were stable, the percentage of uterine blood flow distributed to the placenta in the absence of uterine contractions was not altered by epidural anesthesia or by addition of epinephrine to the anesthetic solution.     

Plasma lidocaine concentrations are higher in twin compared to singleton newborns following epidural anesthesia for Cesarean delivery

PURPOSE: This study compares plasma lidocaine concentrations in 16-sets of twin neonates to 16-singleton neonates all of whom were delivered by Cesarean section under lumbar epidural anesthesia (LEA). METHODS: Lidocaine 1.5% with epinephrine 5 microg x mL(-1) was used for activation of LEA. Upon delivery plasma lidocaine concentrations were measured from the maternal vein (MV), neonatal umbilical vein (UV) and umbilical artery (UA) using TDx fluorescence polarization immunoassay. RESULTS: MV lidocaine concentrations were similar in both twin and singleton mothers. Both mean lidocaine UV and UA levels were 35% higher in twin A (first-delivered) compared to the singleton neonate, (P < 0.01, t test). Similarly, twin B mean UV and UA lidocaine levels were 35% and 53% higher than the singleton value (P < 0.01). Mean UV and UA lidocaine fetal/maternal ratios in both twins were at least 18% higher than the singleton value (P < 0.05). CONCLUSION: Even though there were no differences in neonatal outcome, a potential does exist for high plasma lidocaine concentrations in twin fetuses, suggesting that the total maternal dose of lidocaine must be regulated carefully.     

Comparison of three doses of epidural fentanyl followed by bupivacaine and fentanyl for labor analgesia

Background: Epidural fentanyl 100 μg after lidocaine–epinephrine test dose has been shown to provide adequate analgesia in early labor. This investigation determines the effect of three different bolus doses of epidural fentanyl on duration and quality of analgesia during early first stage of labor. Methods: In this prospective, double‐blind study, 103 laboring nulliparous at cervical dilation <5 cm were enrolled. After an epidural test dose of lidocaine (60 mg) with epinephrine (15 μg), parturients received, randomly, bolus of epidural fentanyl 50, 75, or 100 μg, followed by a continuous infusion of epidural bupivacaine 0.0625% and fentanyl 3 μg/ml at a rate of 10 ml/h. Pain scores and maternal sedation, pruritus, nausea, and vomiting were recorded 10, 20, and 30 min after fentanyl, and every 30 min thereafter until first request for additional analgesia. Results: Adequate analgesia was achieved in 87% (28/32), 94% (35/38), and 94% (31/33) in the fentanyl 50, 75, and 100 μg groups within 20 min. Mean duration of analgesia before re‐dosing was significantly longer in fentanyl 100 and 75 μg groups (185.6±82.9 and 188.5±82.2 min, respectively) as compared with fentanyl 50 μg group (133.6±46.2 min, P<0.016). There was no difference in the incidence of maternal side effects or neonatal Apgar scores among the three groups. Conclusion: After a test dose of lidocaine–epinephrine, the three epidural fentanyl doses produced similar effective labor analgesia. However, epidural fentanyl 75 μg followed by epidural infusion of dilute bupivacaine and fentanyl produced longer duration of analgesia than fentanyl 50 μg followed by the same infusion, with no further prolongation when the dose of fentanyl was increased up to 100 μg.     

Epidural anesthesia worsens uterine blood flow and fetal oxygenation during hemorrhage in gravid ewes.

Recent studies suggest that epidural anesthesia initiated before hemorrhage may improve survival and acid-base status in laboratory animals. However, studies of hemorrhagic shock in nonpregnant animals may not be applicable to less severe hemorrhage in pregnant animals. The purpose of this study was to determine whether epidural anesthesia alters maternal and fetal hemodynamic and acid-base responses to hemorrhage in gravid ewes. Twenty-four experiments were performed in twelve chronically instrumented animals between 0.8 and 0.9 of timed gestation. The experimental sequence included: 1) T = 0 min: normal saline 500 ml intravenously; 2) T = 15 min: epidural administration of 0.5% bupivacaine (epidural group) or normal saline (control group); 3) T = 30 min: epidural administration of additional 0.5% bupivacaine (epidural group only) if the sensory level of anesthesia was below T10; 4) T = 45 min: maternal hemorrhage 20 ml/kg over 55 min; and 5) T = 110 min: transfusion of collected maternal blood over 55 min. At 45 min (i.e., 30 min after the epidural injection of bupivacaine), epidural bupivacaine resulted in a median sensory level of T9 in the epidural group. At that time, maternal mean arterial pressure was less (P less than 0.05) in the epidural group than in the control group (14 +/- 2% below baseline versus 4 +/- 1% above baseline, respectively). Maternal mean arterial pressure, heart rate, cardiac output, and uterine blood flow, and fetal PO2 and pH all were significantly less during hemorrhage (P less than 0.05) in the epidural group than in the control group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Local infiltration of epinephrine-containing lidocaine with bicarbonate reduces superficial bleeding and pain during labor epidural catheter insertion: a randomized trial

BACKGROUND: Superficial bleeding after labor epidural catheter placement is a common phenomenon. In addition to delaying securing the epidural catheter, it may loosen the adhesive catheter dressing. The primary aim of this study was to determine whether skin infiltration with epinephrine-containing rather than plain lidocaine reduces superficial bleeding after catheter placement. Secondary objectives were to determine whether adding epinephrine and/or sodium bicarbonate affected infiltration pain. METHODS: After institutional review board approval and informed consent, 80 healthy women receiving epidural analgesia during labor were randomly assigned in a double-blind manner to four local anesthetic mixtures (n=20 in each group): group L: lidocaine 1.5%, group LB: lidocaine 1.5% with 8.4% sodium bicarbonate, group LE: lidocaine 1.5% with epinephrine 1:200000, and group LEB: lidocaine 1.5% with epinephrine 1:200000 and 8.4% sodium bicarbonate. Clinical endpoints included the amount of superficial bleeding at the catheter site, pain during local anesthetic infiltration and epidural catheter movement during labor. RESULTS: Demographic data were similar among the groups. The addition of epinephrine to lidocaine significantly reduced superficial bleeding. Solutions containing epinephrine were well tolerated and caused no cardiovascular disturbances. The addition of epinephrine did not increase pain, while bicarbonate reduced it [verbal score (scale 0-10) 3.6+/-2.2 vs. 2.6+/-1.8; P=0.04]. There were no differences in epidural catheter movement among the groups; no catheters became displaced during labor. CONCLUSION: Local infiltration of epinephrine-containing lidocaine before epidural catheter insertion reduces superficial bleeding and the addition of bicarbonate decreases pain during skin infiltration.     

Intrathecal sufentanil and fetal heart rate abnormalities: a double-blind, double placebo-controlled trial comparing two forms of combined spinal epidural analgesia with epidural analgesia in labor

Combined spinal epidural analgesia (CSE) for labor pain relief has become increasingly popular. However, the effect of intrathecal sufentanil on the incidence of uterine hyperactivity and fetal heart rate (FHR) abnormalities remains controversial. We hypothesized that the use of intrathecal sufentanil in a dose of 7.5 microg is more likely to induce a nonreassuring FHR tracing than a small dose of spinal sufentanil combined with bupivacaine or epidural analgesia. Three-hundred parturients were randomized into three groups. In the first group, epidural analgesia was initiated with 12.5 mg of bupivacaine, 12.5 microg of epinephrine, and 7.5 microg of sufentanil in a volume of 10 mL (EPD group). In Group 2, initial intrathecal analgesia consisted of 2.5 mg of bupivacaine, 2.5 microg of epinephrine, and 1.5 microg of sufentanil (BSE group); in Group 3, spinal analgesia consisted of 7.5 microg of sufentanil (SUF group). Analgesia was maintained in all groups with patient-controlled epidural analgesia using bupivacaine 0.125%, 1.25 microg/mL of epinephrine, and 0.75 microg/mL of sufentanil (bolus, 4 mL; lockout, 15 min). Cardiotocography was monitored continuously 15 min before analgesia and for 60 min after the start of analgesia. The quality of analgesia, labor, and neonatal outcome and side effects were recorded. Twenty-four percent of patients in the SUF group developed FHR abnormalities (bradycardia or late decelerations) during the first hour after initiation of analgesia compared with 12% in the BSE group and 11% in the EPD group. Uterine hyperactivity occurred in 12% of parturients in the SUF group but in only 2% in the other groups. Onset of analgesia was more rapid in both CSE groups as compared with the EPD group. However, 29% of patients in the BSE group developed severe hypotension, requiring IV ephedrine (29% in the BSE group versus 7% and 12% in the EPD and SUF groups, respectively). All these differences reached statistical significance. The present data corroborate previous recommendations of caution when performing CSE using a large dose (7.5 microg or more) of spinal sufentanil because of the risk of uterine hyperactivity and FHR abnormalities. IMPLICATIONS: Combined spinal epidural analgesia (CSE) produces pain relief during labor. Fetal heart rate changes after CSE using intrathecal sufentanil have been reported. We performed a randomized, blinded trial confirming that fetal heart rate changes are more frequent after CSE using 7.5 micro g of intrathecal sufentanil as compared with other forms of neuraxial labor analgesia.     

Maternal and fetal effects of epinephrine in gravid ewes

Intravenous cannulation by an epidural catheter may complicate epidural anesthesia. Local anesthetic solutions containing epinephrine produce tachycardia and hypertension when given intravenously and may identify intravenous placement. The authors studied the maternal and fetal effects of intravenous epinephrine-containing solutions in ten chronically instrumented gravid ewes. While continuously monitoring maternal and fetal effects, epinephrine 5, 10, or 20 micrograms iv bolus was injected. Solutions of bupivacaine 5 mg and bupivacaine 5 mg combined with epinephrine 10 micrograms given iv were also examined. All epinephrine-containing solutions produced a significant increase (P less than 0.001) in maternal mean arterial pressure, which returned to baseline after 1 min. Maternal heart rates decreased transiently and returned to baseline after 1 min. All epinephrine-containing solutions decreased uterine blood flow (UBF) (P less than 0.001), and, for doses of 10 to 20 micrograms, this decrease lasted more than 3 min. Fetal heart rate and mean arterial blood pressure did not change following any test solution, nor did maternal or fetal arterial blood gas values. The authors conclude that small intravenous boluses of epinephrine decreased UBF in these animals.