Extending epidural analgesia for emergency Caesarean section: a meta-analysis

There is no high-level evidence supporting an optimal top-up solution to convert labour epidural analgesia to surgical anaesthesia for Caesarean section. The aim of this meta-analysis was to identify the best epidural solutions for emergency Caesarean section anaesthesia, with respect to rapid onset and low supplementation of intraoperative block. Eleven randomized controlled trials, involving 779 parturients, were identified for inclusion after a systematic literature search and risk of bias assessment. 'Top-up' boluses were classified into three groups: 0.5% bupivacaine or levobupivacaine (Bup/Levo); lidocaine and epinephrine, with or without fentanyl (LE ± F); and 0.75% ropivacaine (Ropi). Pooled analysis using the fixed-effects method was used to calculate the mean difference (MD) for continuous outcomes and risk ratio (RR) for dichotomous outcomes. Lidocaine and epinephrine, with or without fentanyl, resulted in a significantly faster onset of sensory block [MD -4.51 min, 95% confidence interval (CI) -5.89 to -3.13 min, P < 0.00001]. Bup/Levo was associated with a significantly increased risk of intraoperative supplementation compared with the other groups (RR 2.03; 95% CI 1.22-3.39; P = 0.007), especially compared with Ropi (RR 3.24, 95% CI 1.26-8.33, P=0.01). Adding fentanyl to a local anaesthetic resulted in a significantly faster onset but did not affect the need for intraoperative supplementation. Bupivacaine or levobupivacaine 0.5% was the least effective solution. If the speed of onset is important, then a lidocaine and epinephrine solution, with or without fentanyl, appears optimal. If the quality of epidural block is paramount, then 0.75% ropivacaine is suggested.     

Alkalinization improves the quality of lidocaine-fentanyl epidural anaesthesia for Caesarean section

This double-blind randomized study of 116 healthy women was undertaken to evaluate whether alkalinization potentiated the analgesic effects of epidural fentanyl-lidocaine for elective Caesarean section. After a test-dose of 3 ml, lidocaine 2% with adrenaline 1:200,000, all patients received 100 μg, fentanyl in 5 ml saline and they were then divided into two groups, to receive incremental doses of 5 ml lidocaine 2% with adrenaline 1:200,000 with or without 0.1 mEq · ml^?1 sodium bicarbonate, to obtain anaesthesia to T₄. The addition of bicarbonate to lidocaine resulted in a mean (SD)pH increase from 6.58 (0.01) to 7.14 (0.02) and in a mean PCO₂ increase from 3.8 (0.8) to 345.1 (5.9) mmHg. Onset of sensory analgesia to the S₁ segment as well as the interval between the block and the delivery of the baby were shorter in the bicarbonate group (respectively 15.4 (6.9) vs 18.9 (4.8) min and 28.9 (9.5) versus 33.9 (11.8) min; P < 0.01 and 0.05). No differences were noted in the onset to T₄ or in the degree of motor block. The percentage of patients experiencing pain during surgery and requiring intravenous analgesics was higher in the group which did not receive bicarbonate (3% vs 16%; P < 0.05). There were no differences in intraoperative maternal side-effects, neonatal outcome or in maternal venous and umbilical venous and arterial lidocaine concentrations between the groups. The concentrations of fentanyl in maternal plasma, umbilical artery, and the umbilical artery to maternal vein ratio were greater in the alkalinized group (P < 0.001). In conclusion, alkalinization improves the quality and reliability of epidural anaesthesia provided with fentanyl and lidocaine for Caesarean section in healthy mothers.     

A randomised comparison of 0.5% bupivacaine with a lidocaine/epinephrine/fentanyl mixture for epidural top-up for emergency caesarean section after "low dose" epidural for labour

BACKGROUND: When extending a fentanyl-containing, low-dose labour epidural for emergency caesarean section it has been shown that there is no difference in time to surgical readiness between plain bupivacaine 0.5% and mixtures of lidocaine/epinephrine or lidocaine/bupivacaine/epinephrine. However, it is not known whether adding fentanyl to the lidocaine/epinephrine mixture would increase speed of onset or improve the efficacy of the mixture when topping up for an emergency caesarean section. METHODS: In a prospective, single blind study we compared plain 0.5% bupivacaine with a lidocaine/epinephrine/fentanyl mixture for extending previous low-dose epidural analgesia for emergency caesarean section in 68 patients. RESULTS: There was a significantly longer median preparation time for the mixture than for the single drug (3.0 v 1.25 min: P < 0.0005). The median onset time for block of T7 to touch from the start of the top-up was 13.8 min for the mixture and 17.5 min for plain bupivacaine. This difference was not statistically significant and was offset by the longer preparation time. No general anaesthetics were required for poor blocks and the need for other intraoperative supplementation was not significantly different between the groups (bupivacaine 5/34, lidocaine mixture 2/26). CONCLUSIONS: The use of a lidocaine/epinephrine/fentanyl mixture conferred no clear statistically significant benefit over the use of plain 0.5% bupivacaine when used to extend fentanyl containing low-dose labour epidural analgesia for emergency caesarean section, but the lidocaine solution is cheaper and less toxic than the alternatives.     

Extending low-dose epidural analgesia in labour for emergency Caesarean section - a comparison of levobupivacaine with or without fentanyl

Women in labour receiving epidural analgesia with 15 ml bupivacaine 0.1% and 2 microg.ml(-1) fentanyl followed by 10-15-ml top-ups as required, who needed Caesarean section, were randomly allocated to receive 20 ml levobupivacaine 0.5% over 3 min with either 75 microg fentanyl (1.5 ml) or 1.5 ml saline. Further top-ups or inhaled or intravenous supplementation were given for breakthrough pain. Time to onset (loss of cold sensation to T4 and touch sensation to T5 bilaterally), quality of analgesia and side-effects were recorded. The study was stopped after 112 patients had been randomly assigned, due to a unit protocol change, from midwife-administered top-ups to patient-controlled epidural analgesia. Data from 51 patients given fentanyl and 54 given saline were available for analysis. There were no significant differences in onset times or supplementation between the groups, but there was more intra-operative nausea/vomiting with fentanyl (53%) than with saline (18%; p = 0.004). We found no advantage of adding fentanyl to epidural levobupivacaine when extending epidural analgesia in women already receiving epidural fentanyl during labour and there was an increased incidence of intra-operative nausea and vomiting. Power analysis suggested the same conclusion even had the study proceeded to completion.     

Low-dose epidural top up for emergency caesarean delivery: a randomised comparison of levobupivacaine versus lidocaine/epinephrine/fentanyl

BackgroundLevobupivacaine has a greater safety margin for cardiotoxicity than bupivacaine; consequently it has been recommended as the agent of choice for extending low-dose epidural analgesia for emergency caesarean section. We wished to compare the onset of levobupivacaine with that of a 2% lidocaine/epinephrine/fentanyl mixture.MethodsIn a prospective, single blind study, we compared the speed of onset and efficacy of 20 mL of plain 0.5% levobupivacaine with 2% lidocaine/epinephrine 100 μg/fentanyl 100 μg for extending a previous low-dose labour epidural for emergency caesarean section in 100 patients.ResultsThe median [interquartile range] onset time for block of the T7 dermatome to touch from the end of the top up for 2% lidocaine /epinephrine/fentanyl mixture and levobupivacaine was 10 [8, 13] vs. 15 [10, 20] min respectively (P < 0.0009). There was a significantly longer preparation time for the 2% lidocaine/epinephrine/fentanyl mixture than for levobupivacaine (median 145 s [120, 200] vs. 60 s [44, 60] P < 0.0009). Even with the inclusion of the longer preparation time, 2% lidocaine/epinephrine/fentanyl still had a more rapid onset than levobupivacaine: 15 [15, 19] vs. 18 [13.8, 22.4] min (P < 0.05). General anaesthesia was not required for inadequate blocks but additional local anaesthetic or intraoperative analgesic supplements were needed more frequently in the levobupivacaine group: 9% vs. 29%, (P < 0.01).ConclusionsA freshly prepared mixture of 2% lidocaine 20 mL plus epinephrine 100 μg and fentanyl 100 μg provides a more rapid onset and superior quality T7 block to touch than 0.5% levobupivacaine 20 mL.     

Epidural lidocaine-bicarbonate-adrenaline vs levobupivacaine for emergency Caesarean section: a randomised controlled trial

Epidural mixtures containing lidocaine with or without additives are commonly used to convert epidural analgesia in labour to anaesthesia for emergency Caesarean section, but direct comparisons with alternative, single agents in this situation are few. In a prospective double-blinded trial, we compared a freshly prepared lidocaine-bicarbonate-adrenaline mixture (final concentrations 1.8%, 0.76% and 1:200,000, respectively) with our standard agent, levobupivacaine 0.5%, for extending epidural blockade for emergency Caesarean section. Using a sequential analysis technique, with data analysed in blocks of 40, women receiving epidural analgesia in labour who required top-up for Caesarean section were randomly assigned to receive 20 ml of epidural solution over 3 min. The first analysis (n = 40) indicated that the study should be stopped, as significant differences were found in our primary outcome data. Median (IQR [range]) times to reach a block to touch to T5 and cold to T4 were, respectively, 7 (6-9 [5-17]) min and 7 (5-8 [4-17]) min for lidocaine-bicarbonate-adrenaline, and 14 (10 -17 [9-31]) min and 11 (9-14 [6-30]) min for levobupivacaine (p = 0.00004 and 0.001, respectively). Pre- and intra-operative supplementation/pain, maternal side-effects and neonatal outcomes (excluding five women who underwent instrumental delivery) were similar between the groups. Intra-operative maternal sedation (scored by the mother on a 10-point scale) was greater with lidocaine-bicarbonate-adrenaline (4.5 (3-8 [1-9])) than with levobupivacaine (3 (1-4 [1-7])), but not significantly so (p = 0.07). We conclude that epidural lidocaine-bicarbonate-adrenaline halves the onset time when extending epidural analgesia for Caesarean section although there is a possibility of increased maternal sedation.     

Epidural top-up solutions for emergency caesarean section: a comparison of preparation times

We compared the preparation times of three solutions commonly used for epidural top-up for emergency Caesarean section. Twenty-two anaesthetists were asked to prepare fresh solutions in random order as quickly as possible: 0.5% bupivacaine 20 ml (B); 2% lidocaine 20 ml with 1:200,000 epinephrine (LE); and 0.5% bupivacaine 10 ml and 2% lidocaine 10 ml with 1:200,000 epinephrine and 8.4% sodium bicarbonate 2 ml (BLEB). Preparation times for B were approximately half of those for LE, which in turn were approximately half of those for BLEB (P = 0.0001). If local anaesthetic solutions with additives such as epinephrine or bicarbonate are prepared just before emergency Caesarean section, any possible reduction in onset time that they might afford may be offset by the additional preparation time required.      

Effects of volume and concentration of lidocaine on epidural anaesthesia in pregnant females

BACKGROUND AND OBJECTIVE: The effects of altering the concentration of a local anaesthetic on the development of epidural anaesthesia in pregnant females are unclear. We compared the anaesthetic effects of a constant dose of two different concentrations of epidural lidocaine for Caesarean section. METHODS: After Institutional Review Board approval and informed consent, patients undergoing elective Caesarean section were randomized to receive either lidocaine 1% 30 mL (+epinephrine 5 microg mL(-1)) or lidocaine 2% 15 mL (+epinephrine 5 microg mL(-1)) (n = 20 each) for epidural anaesthesia at the L1-L2 interspace. The spread of the sensory block to pinprick and the degree of motor block (modified Bromage scale) were measured at 5, 10, 15, 20 and 30 min after injection. RESULTS: No significant differences in the progression of analgesia and motor block were observed at any time between 1 and 2% lidocaine. The maximum cephalad spread was observed 30 min after injection; the median was at T4 (range T3-T5) and at T4 (range T3-T6) for lidocaine 1 and 2%, respectively. CONCLUSIONS: The same doses but different volumes of lidocaine 1 and 2% produced comparable anaesthetic effects in pregnant females. The effects of epidural anaesthesia depend primarily on the total dose of the local anaesthetic.     

Patient-controlled epidural fentanyl following spinal fentanyl at Caesarean section

Spinal fentanyl can improve analgesia during Caesarean section. However, there is evidence that, following its relatively short-lived analgesic effect, there is a more prolonged spinal opioid tolerance effect. The effectiveness of postoperative epidural fentanyl analgesia may therefore be reduced following the use of spinal fentanyl at operation. This randomised, double-blind study was designed to assess whether patient-controlled epidural fentanyl could produce effective analgesia following 25 microg of spinal fentanyl at operation. Patients undergoing elective Caesarean section received spinal bupivacaine combined with either fentanyl 25 microg (fentanyl group; n = 18) or normal saline (saline group; n = 18). Patient-controlled epidural fentanyl was used for postoperative analgesia. The fentanyl group used a mean of 23.4 (SD 14.5) microg x h(-1) of fentanyl, compared with 27.0 (10.8) microg x h(-1) for the saline group (p =0.41). Using a 0-100 mm visual analogue score for pain, the maximum pain score recorded at rest for the fentanyl group was median 24 [IQR 15-35] mm, compared with 15 [13-45] mm for the saline group (p = 0.41). The maximum pain score recorded on coughing for the fentanyl group was 29 [24-46] mm, compared with 27 [19-47] mm for the saline group (p = 0.44). Nine of the fentanyl group rated postoperative analgesia as excellent and nine as good, compared with 10 of the saline group who rated it as excellent and eight as good (p = 0.74). Epidural fentanyl can produce effective analgesia following the use of 25 microg spinal fentanyl at Caesarean section.     

Spinal anaesthesia with lidocaine 2% for Caesarean section

Spinal anaesthesia with 2, 2.5 or 3 ml of glucose-free lidocaine 2% was studied in 50 patients undergoing Caesarean section. Onset time, cephalad spread of analgesia, quality of analgesia, muscle relaxation, the cardiovascular effects and duration of analgesia and motor block were assessed. Reliable anaesthesia was provided with 2.5 and 3 ml while 2 ml of 2% lidocaine was insufficient. Onset time varied between 5.5 to 6 min and maximum cephalad spread was achieved in 10-15 min. The mean maximum extent of sensory analgesia was higher after 2.5 ml (T4.1) and 3 ml (T3.6) than after 2 ml (T7) (P < 0.001). Complete motor block was achieved in all the patients. The mean duration of sensory block was 123 +/- 6.23 min (2 ml) to 126 +/- 7.53 min (2.5 and 3 ml). The mean duration of motor block in 2.5 and 3 ml groups was higher (P < 0.001) than in the 2 ml group and was correlated with the dose of lidocaine (P < 0.05). Hypotension (SBP < 100 mmHg) was noted in 10% (n = 5) of patients in whom the cephalad spread of analgesia was also higher. All the neonates had an apgar score of 7 or more at 1 min. These results suggest that 2.5 to 3 ml of 2% lidocaine provides satisfactory anaesthesia for Caesarean section.     

Chemical stability of bupivacaine, lidocaine and epinephrine in pH-adjusted solutions

Epinephrine and sodium bicarbonate may be added to local anaesthetic solutions in order to reduce the onset time and enhance the quality of epidural anaesthesia for Caesarean section. Such mixtures are sometimes prepared several hours in advance for subsequent use in emergency Caesarean section through a pre-existing epidural catheter. To evaluate this practice, we studied the chemical stability in solution over 24 h of nine epidural mixtures consisting of different combinations of bupivacaine, lidocaine, epinephrine and sodium bicarbonate. In mixtures alkalinised with sodium bicarbonate, epinephrine concentrations decreased significantly over 24 h (p<0.0001), whereas those in nonalkalinised mixtures did not change with time. Bupivacaine and lidocaine concentrations in all mixtures did not decrease over time regardless of alkalinisation. We do not recommend adding epinephrine to alkalinised epidural solutions that are to be stored for a prolonged period before clinical use.     

Epidural anaesthesia for caesarean section in an achondroplastic dwarf

We describe the anaesthetic management of a parturient with achondroplasia presenting for Caesarean section under epidural anaesthesia. A block extending from T4 to S4 was established over 25 min using a total of 12 ml of 2.0% lidocaine (lignocaine) with epinephrine (adrenaline) 1:200,000 and fentanyl 37.5 micrograms. Apart from mild discomfort during peritoneal incision, her perioperative course was uneventful. Achondroplasia is reviewed and the anaesthetic implications of the condition are discussed.      

The extension of epidural blockade for emergency Caesarean section: a survey of current UK practice

The conversion of epidural analgesia during labour to surgical anaesthesia for Caesarean section can have important medical and medicolegal implications. This survey sought to establish the current management for extending epidural blockade for emergency Caesarean section. A postal questionnaire was sent to the lead obstetric anaesthetist in all maternity units in the UK (n = 254). The response rate was 82% (n = 209). Of those surveyed, 68% (136) give the full dose of the local anaesthetic mixture in the delivery room, whilst 12.5% (25) initiate the top-up in the delivery room and give the remainder of the dose in theatre. Fifteen per cent (30) transfer the woman to theatre before commencing anaesthesia and 34% (68) give a test dose before the full anaesthetic dose. Guidelines for converting labour analgesia to anaesthesia for emergency Caesarean section were available in 64% (128) units. Bupivacaine 0.5% was the most commonly used agent, being used as the sole agent by 41.5% (81) units and in combination by a further 18% (36). Adrenaline was added to the chosen local anaesthetic by 30% (60) whilst 12% (24) added bicarbonate. In all, 13 combinations of local anaesthetics and adjuncts were used. The mode time to transfer the patient to theatre was 1 min. Of the 161 respondents who commenced anaesthesia in the delivery room, 71% (114) did not monitor the patient during transfer, whilst 87% (140) had ephedrine immediately available. Thirty-three respondents reported a total of 43 adverse incidents associated with the extension of epidural blockade. These included high blocks, inadequate blocks and possible intravascular injections, the latter resulting in two seizures and one cardiac arrest.     

The addition of hydromorphone to epidural fentanyl does not affect analgesia in early labour

PURPOSE: Epidural fentanyl after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labour. The current study was designed to determine the influence of hydromorphone added to an epidural fentanyl bolus (e.g., whether there is an increase in duration of analgesia). METHODS: Forty-four labouring primigravid women, at less than 5 cm cervical dilation, who requested epidural analgesia were enrolled in this randomized, double-blind study. After a 3 mL test dose of lidocaine with epinephrine, patients received fentanyl 100 microgram (in 10 mL volume). They randomly received the fentanyl with either saline or hydromorphone (300 microgram). After administration of the initial analgesic, pain scores and side effects were recorded for each patient at ten, 20, and 30 min, and every 30 min thereafter, by an observer blinded to the technique used. RESULTS: The patients were taller in the hydromorphone group (P < 0.04). There were no other demographic differences between the two groups. The mean duration prior to re-dose was not significantly different in the group that received hydromorphone (135 +/- 52 min) compared to the control group (145 +/- 46 min). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. CONCLUSION: In early labouring patients, the addition of hydromorphone (300 microgram) to epidural fentanyl (100 microgram after a lidocaine and epinephrine test dose) neither prolongs the duration of analgesia nor affects the ability to ambulate, and cannot be recommended according to the current study.     

Epidural nalbuphine for analgesia following caesarean delivery: dose-response and effect of local anaesthetic choice

The analgesic profile of epidural nalbuphine for postoperative pain relief and the impact of local anaesthetic choice upon this profile was investigated in 58 patients undergoing elective Caesarean delivery under epidural anaesthesia. Patients were randomized to receive either lidocaine 2% with 1:200,000 epinephrine or 2-chloroprocaine 3% for perioperative anaesthesia, followed by either 10, 20, or 30 mg of epidural nalbuphine administered at the first complaint of postoperative discomfort. Postoperative analgesia was quantitated on a visual analogue (VAS) scale, and by the time from the epidural opioid injection until the first request for supplemental pain medication. The duration of analgesia after lidocaine anaesthesia followed by 10, 20 or 30 mg nalbuphine was 77 (53-127) min, 205 (110-269) min, and 185 (116-241), respectively (median, 95% confidence interval, P less than 0.01, 20 and 30 mg vs 10 mg). Following 2-chloroprocaine anaesthesia, VAS remained consistently elevated: the median duration of analgesia was only 30-40 min and did not differ among the three doses of nalbuphine. Side-effects consisted only of somnolence, and were noted only following lidocaine anaesthesia. Somnolence was observed in 0, 20% and 50% of those receiving 10 mg, 20 mg and 30 mg of nalbuphine respectively (NS). No evidence of respiratory depression was noted in any patient. It is concluded that 20 or 30 mg of epidural nalbuphine provides analgesia for only two to four hours following Caesarean delivery with lidocaine anaesthesia, but anaesthesia with 2-chloroprocaine resulted in minimal or no analgesia from this opioid. Nalbuphine appears to be a disappointing agent for epidural use after Caesarean delivery.     

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 fentanyl does not influence intravenous PCA requirements in the post-Caesarean patient

Forty ASA physical status I or II patients scheduled for elective Caesarean delivery were studied to determine the effect ofepidural fentanyl on post-Caesarean delivery analgesic requirements as administered by intravenous patient-controlled analgesia (PCA). Following delivery of the infant, under epidural anaesthesia with lidocaine 2% with 11200,000 epinephrine, patients were randomly assigned to receive either 10 ml of preservative-free normal saline via theepidural catheter or 100 μg of fentanyl with 8 ml preservative-free normal saline in a double-blinded fashion. On arrival in the post-anesthesia recovery room (PAR), patients were provided with intravenous PCA meperidine 12.5 mg every eight minutes as needed. Patients were visited at intervals over the next 24 hr to determine if any differences in narcotic requirements, demands for narcotics, or severity of pain were noted. No differences were observed in any values between the groups. It is concluded that a single bolus of épidural fentanyl does not provide an advantage for postoperative pain relief in this patient population.     

The influence of a bupivacaine and fentanyl epidural infusion after epidural fentanyl in patients allowed to ambulate in early labor

Epidural fentanyl after a lidocaine and epinephrine test dose provides adequate analgesia and allows for ambulation during early labor. This study was designed to determine the influence of an epidural infusion of bupivacaine plus fentanyl administered after initiation of epidural labor analgesia with fentanyl. Specifically, we evaluated whether there is an increase in motor block or an increased time to request for further analgesic medication. Fifty-one laboring primigravid women at <5 cm cervical dilation who requested epidural analgesia were enrolled. After a 3-mL epidural test dose of 1.5% lidocaine with epinephrine (5 microg/mL), patients received fentanyl 100 microg via the epidural catheter. They then randomly received either an infusion (10 mL/h) of 0.0625% bupivacaine with fentanyl (3 microg/mL) or an infusion of preservative-free saline. After the administration of the initial analgesic, pain scores and side effects were recorded for each patient at 10, 20, and 30 min, every 30 min thereafter, and at the time of request for additional analgesic medication, by an observer blinded to the technique used. There were no demographic differences between the two groups. The mean duration of analgesia (time from initial dose to request for additional analgesia) was increased in the group that received a continuous infusion of bupivacaine and fentanyl compared with the Saline group (198 +/- 86 vs 145 +/- 50 min; P < 0.009). Side effects were similar between the two groups. No patient in either group experienced any detectable motor block. Fourteen patients chose to ambulate in the Saline group, and 12 patients chose to ambulate in the Infusion group. In early laboring patients, a continuous infusion of 0.0625% bupivacaine infusion with fentanyl (3 microg/mL) prolonged the duration until top-up was required, after epidural fentanyl 100 microg after a lidocaine and epinephrine test dose, and did not cause any clinically detectable motor block. IMPLICATIONS: A 0.0625% bupivacaine and fentanyl (3 microg/mL) infusion, when added to epidural fentanyl (100 microg), prolongs the analgesic duration without increasing motor block in women in early labor.     

Labor analgesia with epidural bupivacaine plus fentanyl: enhancement with epinephrine and inhibition with 2-chloroprocaine

Epidural injection of drug combinations may decrease toxicity by decreasing the dose of each component, but may also result in detrimental drug interactions. In this study interactions among bupivaciane, fentanyl, epinephrine, 2-chloroprocaine, and lidocaine for epidural analgesia during labor were examined. In part 1 of the study, healthy parturients received in a random manner either 10 ml of 0.25% bupivacaine with 5 micrograms/ml fentanyl (n = 50), or 10 ml of this combination with 3.33 micrograms/ml freshly added epinephrine (n = 50). Epinephrine prolonged the median duration of pain relief (180 vs. 138 min, P less than 0.05) without affecting duration of first or second stages of labor, or neonatal Apgar scores. Blood pressure decreased slightly more in those receiving epinephrine, although the incidence of hypotension requiring treatment did not differ between groups. Part 2 of the study evaluated the possibility that local anesthetic used for confirming catheter tip location may interfere with the analgesic action of this bupivacaine-fentanyl-epinephrine (BFE) combination. In 50 additional parturients, a test dose of either 2-chloroprocaine (n = 25) or lidocaine (n = 25) was injected through the epidural catheter and was followed by injection of the BFE mixture. The lidocaine test dose group had a greater duration of analgesia than the 2-chloroprocaine test dose group (median duration of 164 vs. 91 min, P less than 0.05). The authors conclude that the addition of epinephrine 3.33 micrograms/ml significantly increases the duration of analgesia obtained from 0.25% bupivacaine with 5 micrograms/ml fentanyl. However, prior injection of 2-chloroprocaine, but not lidocaine, significantly decreases the duration of analgesia achieved with this BFE mixture.     

Comparison of epidural fentanyl versus epidural sufentanil for analgesia in ambulatory patients in early labor

Epidural sufentanil, after a lidocaine and epinephrine test dose, provides adequate analgesia and allows for ambulation during early labor. Epidural fentanyl has not been evaluated in this setting. The current study was designed to determine whether there is an analgesic difference between epidural fentanyl and epidural sufentanil in laboring patients. Forty-six laboring nulliparous women, at <5-cm cervical dilation, who requested epidural analgesia were enrolled. After a 3-mL test dose of lidocaine with epinephrine, patients were randomized to receive either sufentanil 20 microg or fentanyl 100 microg. After administration of the analgesic, pain scores and side effects were recorded for each patient at 5, 10, 15, 20, and 30 min and every 30 min thereafter, by an observer blinded to the technique used. There were no demographic differences between the two groups. Pain relief was rapid for all patients. The mean durations of analgesia were similar between the sufentanil group (138 +/- 50 min) and the fentanyl group (124 +/- 42 min). Side effects were similar between the two groups. In early laboring patients, epidural fentanyl 100 microg, after a lidocaine and epinephrine test dose, provides analgesia comparable to that of sufentanil 20 microg. Implications: In early laboring patients, epidural fentanyl 100 microg, after a lidocaine and epinephrine test dose, provides analgesia comparable to that of sufentanil 20 microg.