Bupivacaine versus bupivacaine plus fentanyl for epidural analgesia: effect on maternal satisfaction

Investigation of the Minimum Local Analgesic Concentration of Epidural Sufentanil Combined With Ropivacaine for Labor Analgesia

PURPOSE

Worldwide, there are only few studies focusing on labor analgesia on the MLAC (minimum local analgesic concentration) or EC50 (median effective concentration) of sufentanil and ropivacaine. Therefore, we determine the MLAC or EC50 of sufentanil and ropivacaine for epidural analgesia by using an up-down sequential allocation and survey its adverse effect in a prospective blinded randomized trial.

METHODS

Sixty nulliparous full-term parturients who required labor analgesia were recruited and randomly divided into the sufentanil and ropivacaine groups. The formulation was 25 μg sufentanil combined with 0.1% ropivacaine (added 0.9% normal saline to 75 ml). According to the response of a previous parturient, the dosage of sufentanil was increased or decreased by 5 μg in the sufetanil group; meanwhile, we also administrated an initial concentration of 0.1% ropivacaine combined with 22.5 μg sufentanil (added 0.9% normal saline to 75 ml) in the ropivacaine group. The concentration of ropivacaine was increased or decreased by 0.01% following the response of the previous parturient. The Brownlee up-down sequential allocation was used to estimate the MLAC of epidural ropivacaine and its 95% confidence intervals in labor analgesia.

FINDINGS

There were no significant changes for the two groups, including for age, height weight, active stage, second stage of labor, and gestational weeks (P = 0.769, 0.900, 0.603, 0.441, 0.577, and 0.695, respectively). The VAS scores of the parturient decreased to varying degrees (P < 0.0001) after labor analgesia compared with VAS before labor analgesia, and the most effective analgesia was reached in 60 min. The EC50 dose of epidural ropivacaine combined with 0.3 μg/mL sufentanil was 0.09687%, and the 95% CI was 0.08944%~0.1043%. Five parturients had PONV, and the incidence rate was 16.7%; one parturient had pruritus, so the incidence rate was 3.3%. The EC50 dose of epidural sulfetanil combined with 0.1% ropivacaine was 18.76 μg with a 95% confidence interval of 13.5-24.48 μg. There were no significant differences in the active stage, second stage of labor, and maternal and fetal hemodynamic data between the two groups. Notably, the Apgar scores for 1 min and 5 min were 10 scores for almost all of these patients. There were no significant differences between the two groups for maternal and fetal side effects, which had very low incidence rates.

IMPLICATIONS

The MLAC of epidural sufentanil or ropivacaine could provide satisfactory and safe analgesia for parturients while having a low incidence rate of side effects.

A double-blind study on analgesic effects of fentanyl combined with bupivacaine for extradural labor analgesia

Background:

The intermittent technique of labor extradural analgesia has been showing promising results over other techniques. This study was done to assess and compare the efficacy of two different doses of fentanyl mixed with low doses of bupivacaine in intermittent labor extradural analgesia.

Materials and Methods:

90 ASA grade I-II parturients in active labor with a cervical dilatation of 3–7 cm were randomly allocated to three different groups:

Group A: 10 ml bupivacaine 0.125% + fentanyl 10 μg (1 μg/ml)

Group B: 10 ml bupivacaine 0.125% + fentanyl 20 μg (2 μg/ml)

Group C: 10 ml bupivacaine 0.125% (the control group)

All patients were preloaded with 10-15 ml/kg Lactated Ringer's solution. Labor analgesia was maintained by intermittent boluses of the drug combination.

Results:

The mean time of the onset of analgesia was significantly lower (P<0.05) and the duration of analgesia was significantly higher (P<0.01) in Group B when compared with Groups A and C (P<0.001). Patient satisfaction was considerably better in Group B (P<0.01). However, in both groups, the progression of labor was found to be slightly more prolonged than Group C. The level of the sensory and motor block was comparable in both the groups and was at the T8–T10 level; it was comparable and the level of motor blockade (Bromage score = 0, 1) in each group was also not significant (P>0.05).

Conclusion:

The addition of fentanyl (2 μg/ml) to bupivacaine 0.125% decreases the time of the onset of analgesia and increases the duration of analgesia and level of maternal satisfaction during labor as compared to fentanyl (1 μg/ml).

0.2% ropivacaine with fentanyl in the management of labor analgesia: A case study of 30 parturients

BACKGROUND

Epidural infusion of 0.2% ropivacaine is recommended by the manufacturers for labor analgesia.

AIMS

The aim of this study is to evaluate the analgesic efficacy, degree of motor blockade, obstetric outcome in the form of incidence of normal vaginal, assisted vaginal and lower segment cesarean section.

SETTINGS AND DESIGN

Pilot study.

MATERIALS AND METHODS

In this pilot study, 30 nulliparous parturients in active labor had epidural analgesia established using 0.2% ropivacaine with 25 mcg fentanyl for initiation when cervical dilatation was 3-4 cm and then analgesia was maintained with 0.2% ropivacaine at 10 ml/h till the delivery of baby.

STATISTICAL ANALYSIS

It was done by Wilcoxon sign rank test and paired t-test as applicable.

RESULTS

There was a significant difference (P < 0.05) between prebolus, postbolus and postinfusion with respect to visual analog score. There was a significant difference (P > 0.05) between prebolus, postbolus, and postinfusion with respect to Bromage motor score, (Wilcoxon sign rank test). Six out of 30 paturients complained of tingling and heaviness in lower limbs after continuous infusion of 2-2.5 h.

CONCLUSION

We conclude that 0.2% ropivacaine (8 ml) with fentanyl 25 mcg is good for initiation of ambulatory labor analgesia. But for maintenance of labor analgesia lower concentration of ropivacaine may be preferred.

The effects of epidural/spinal opioids in labour analgesia on neonatal outcomes: a meta-analysis of randomized controlled trials

PURPOSE

Epidural/spinal opioids are increasingly used to relieve parturients' pain in labour. Some studies indicate that opioids can induce side effects in neonates, such as respiratory depression and neurobehavioural changes. This meta-analysis aimed to clarify the effects of opioids in labour analgesia on neonates.

SOURCE

PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE™ were searched for relevant randomized controlled trials (RCTs). The neonatal data of Apgar scores, Neurological and Adaptive Capacity Scores (NACS), and umbilical cord pH values were extracted. Statistical analyses were carried out using Review Manager 5.2 and Stata(®) 10.

PRINCIPAL FINDINGS

Twenty-one trials with 2,859 participants were included in our meta-analysis. No difference in the incidence of Apgar scores < 7 was shown between the opioid and control groups at one minute (risk difference [RD] 0.0%, 95% confidence interval [CI]: -3.0 to 2.0, P = 0.78; I (2) = 0%, 95% CI: 0 to 50) and at five minutes (RD -1.0%, 95% CI: -2.0 to 1.0, P = 0.31; I(2) = 0%, 95% CI: 0 to 50). No significant differences were found in the NACS at two hours (mean difference [MD] -0.35, 95% CI: -1.70 to 1.01, P = 0.62; I(2) = 0%, 95% CI: 0 to 79) and at 24 hr (MD -0.45, 95% CI: -1.36 to 0.46, P = 0.33; I(2) = 3%, 95% CI: 0 to 26). Also, no significant differences were found in umbilical cord artery pH (MD -0.02, 95% CI: -0.06 to 0.03, P = 0.48; I(2) = 80%, 95% CI: 46 to 92) and vein pH (MD -0.03, 95% CI: -0.07 to 0.00, P = 0.08; I(2) = 77%, 95% CI: 36 to 91). No significant publication bias was found.

CONCLUSION

The common doses of fentanyl and sufentanil used with an epidural/spinal technique in labour analgesia are safe for neonates up to 24 hr after delivery. In future studies, more attention should be paid to the long-term side effects in neonates.

Prospective longitudinal cohort questionnaire assessment of labouring women's preference both pre- and post-delivery for either reduced pain intensity for a longer duration or greater pain intensity for a shorter duration

BACKGROUND

Assessments of labour pain focus on pain intensity, not on duration. We aimed to assess the importance labouring women apply to pain intensity and duration before labour and post-delivery.

METHODS

Forty healthy women scheduled for labour induction were enrolled in this institutional review board-approved, prospective cohort study. Participants completed a pain preference questionnaire before active labour and within 24-h of delivery. The questionnaire consisted of seven stem questions that evaluated preference for pain intensity or duration. The pain preference ratio was determined by dividing the percentage of women who preferred reduced pain intensity for longer duration by that of those who preferred greater pain intensity for shorter duration (estimate of the odds). The overall hypothetical pain burden was determined by multiplying intensity by time. All questions presented the same overall hypothetical pain burden.

RESULTS

Pain preference questionnaire scores demonstrated preference for low intensity pain for a longer duration rather than higher intensity for a shorter duration, both pre-labour (P<0.001) and post-delivery (P<0.001): the null median imputed as 3 of 6 (i.e. no preference for pain intensity over pain duration). This preference for pain duration over intensity was greater post-delivery compared with before labour (P=0.03). There was a significant correlation (r=0.83; P=0.04) between the pain preference ratio vs overall hypothetical pain burden before labour but not after delivery (r=0.28; P=0.59).

CONCLUSIONS

In this preliminary labour assessment, women preferred lower pain intensity at the cost of longer pain duration. This suggests that pain intensity is the primary driver of hypothetical pain burden-a preference reinforced post-delivery.

Epidural labour analgesia using Bupivacaine and Clonidine

BACKGROUND

To compare the effects of addition of Clonidine (60 μg) to Epidural Bupivacaine (0.125%) for labour analgesia, with regard to duration of analgesia, duration of labour, ambulation, incidence of instrumentation and caesarean section, foetal outcome, patient satisfaction and side effects. PATIENTS #ENTITYSTARTX00026;

METHODS

On demand, epidural labour analgesia was given to 50 nulliparous healthy term parturients (cephalic presentation), divided in two groups randomly. Group I received bupivacaine (0.125%) alone, whereas Group II received bupivacaine (0.125%) along with Clonidine (60 μg). 10 ml of 0.125% bupivacaine was injected as first dose and further doses titrated with patient relief (Numerical Rating Scale <3). Top ups were given whenever Numerical Rating Scale went above 5.

RESULTS

There was statistically significant prolongation of duration of analgesia in Group II, with no difference in duration of labour, ambulation, incidence of instrumentation and caesarean section or foetal outcome. Also clonidine gave dose sparing effect to bupivacaine and there was better patient satisfaction without any significant side effects in Group II.

CONCLUSION

Clonidine is a useful adjunct to bupivacaine for epidural labour analgesia and can be considered as alternative to opioids.

A randomized controlled trial using patient-controlled epidural analgesia with 0.25% versus 0.0625% bupivacaine in nulliparous labor: effect on analgesia requirement and maternal satisfaction

BACKGROUND

The effect of epidural local anesthetic concentration on analgesic action is still the subject of debate. This study compared the effect of a four-fold change in concentration of bupivacaine for epidural analgesia in labor.

METHODS

Nulliparous women in early active labor were recruited. All women received analgesic drugs via a lumbar epidural catheter, and all received fentanyl 1 microg/kg with the epidural induction dose and no further opioids throughout the study. Patients were randomized to receive either a 5-mL bolus followed by a 5-mL/h infusion of concentrated (0.25%) bupivacaine or a 20-mL bolus followed by a 20-mL/h infusion of dilute (0.0625%) bupivacaine. Patient-controlled epidural analgesia of the study solution was then used to assess additional analgesia requirements. Analgesic requirement, maternal satisfaction and obstetric outcome were compared.

RESULTS

For subjects receiving 0.25% bupivacaine, the median total dose of drug administered was greater (117 vs. 90 mg, P=0.0008), and the mean maternal satisfaction score was less (82 vs. 93, P=0.04) than with the 0.0625% solution.

CONCLUSIONS

Larger volumes of more dilute solutions may result in dose sparing and provide more effective labor analgesia. This study supports the continued trend towards dilute local anesthetic mixtures for labor epidural analgesia.

An analysis of the need for anesthetic interventions with differing concentrations of labor epidural bupivacaine: an observational study

BACKGROUND

Labor epidural analgesia techniques using lower concentrations of bupivacaine are designed to maintain pain control with fewer side effects such as hypotension and motor block. However, the increase in sensation may allow breakthrough pain resulting in the need for additional interventions. We examined the number of interventions, both for analgesia and for treatment of side effects, required when using three concentrations of bupivacaine.

METHODS

Retrospective observational investigation examining 4493 women who received epidural analgesia during two periods. In the first period, higher concentrations of bupivacaine were used (0.125% and 0.0625%, both with fentanyl 2 microg/mL). In the second period, a very low concentration was used (0.04% plus fentanyl 1.7 microg/mL and epinephrine 1.7 microg/mL). Outcomes were compared using univariate tests, and multivariate Poisson regression was used to identify independent factors influencing interventions.

RESULTS

The frequencies of interventions were similar for women receiving bupivacaine concentrations of 0.04% (1.4+/-2.0) and 0.125% (1.5+/-2.0), while women receiving the 0.0625% solution required more interventions (1.8+/-2.3; P<0.001). Women who received 0.04% or 0.0625% bupivacaine required more treatment of breakthrough pain (P<0.002), while those receiving 0.125% bupivacaine required more treatment for hypotension and motor block (P<0.05). Multivariate Poisson regression showed that duration of treatment, maternal age and body mass index were independent factors for the number of interventions.

CONCLUSIONS

Neither the total interventions nor intervention rate per hour varied significantly with the concentrations of bupivacaine used in this study. Lower concentrations produced fewer side effects including hypotension, while the higher concentration resulted in less breakthrough pain.

Epidural analgesia for childbirth: effects of newer techniques on neonatal outcome

New low-dose, local anesthetic-opioid combinations, combined spinal epidural analgesia, and new anesthetic drugs, such as ropivacaine and levobupivacaine, have modified the anesthetic practice in obstetric labor analgesia. These new analgesic techniques have less or no neonatal effects when compared with traditional epidural labor analgesia. They also have less effect on mode of delivery, which may in turn affect neonatal outcome. The use of very diluted or low concentrations of local anesthetic solutions may reduce their placental passage and thus the possible subtle neonatal effects. Small doses of epidural or spinal opioids alone or combined with low doses of local anesthetics does not affect the well-being of the neonate at birth. When considering the neonatal outcome, combined spinal epidural analgesia is as well tolerated as low-dose epidural analgesia. Transient fetal heart rate changes have been described immediately after the administration of intrathecal or epidural opioids. Maternal hypotension may also occur at the onset of epidural analgesia. Whether the occurrence of transient fetal heart rate changes or maternal hypotension immediately after the epidural block may influence the neonatal outcome at birth needs verification.

Motor block during epidural infusions for nulliparous women in labour: a randomized double-blind study of plain bupivacaine and low dose bupivacaine with fentanyl

Sixty nulliparous women received epidural infusions in labour of either 0.125% plain bupivacaine or 0.0625% bupivacaine containing 2.5 mcg/ml fentanyl both starting at 12 ml/h and titrated to maintain a sensory block to T10. Those women who received low dose bupivacaine with fentanyl took significantly longer to reach full cervical dilation (P < 0.05). There was no statistical difference between the groups in the number of additional epidural bolus doses required during the infusions. Of the women receiving low dose bupivacaine with fentanyl, 77% required one or no additional top-up doses compared to 87% in the plain bupivacaine group. There was no reduction in the incidence of perineal pain in the group who received fentanyl. Significantly more women who received 0.125% bupivacaine had motor block after 2 h of the infusion (P < 0.05). The mode of delivery was similar in the two groups as was the satisfaction with epidural analgesia in both the first and second stages of labour and with labour overall. There were no significant differences in Apgar scores, umbilical cord blood pH levels or neurologic and adaptive capacity scores at 2 or 24 h. There was no significant difference in the incidence of symptoms 24 h after delivery.

Delivery room analgesia: an analysis of maternal satisfaction

On the first post-partum day, 324 mothers completed a questionnaire designed to assess maternal perception of delivery room experience. Antenatal pain expectation, actual pain severity, analgesia received, as well as maternal satisfaction and choice of analgesia for future deliveries were recorded. Forty-five percent of primiparae and 36% of multiparae reported that they anticipated suffering extreme pain during delivery. The incidence of unbearable pain was similar among patients who received no analgesia or intravenous pethidine but significantly (P<0.0001) higher when compared to epidural analgesia. During the first stage of labour, continuous epidural analgesia was associated with severe or unbearable pain in 51% and 58% of primiparae and multiparae, respectively. The incidence of severe or unbearable pain during the second stage of labour was 43% and 46% for primiparae and multiparae, respectively. Patient satisfaction with epidural analgesia did not correlate with subjective pain scores. Among mothers who received continuous epidural analgesia 70% described their experience as good or excellent and 65.8% indicated that they would request similar pain relief in the future. Despite advances in obstetric analgesia, women anticipate and actually experience severe pain during childbirth. However, due to psychological and cultural factors, as well as possible post-partum euphoria, satisfaction with the delivery room experience is high.

Maternal temperature during labour using low-dose (ambulatory) epidural analgesia with bupivacaine and fentanyl

Maternal temperature is known to increase during labour with conventional epidural analgesia mixtures. To date, the effect of newer low-dose (ambulatory) epidural concentrations on maternal temperature has not been studied. Twenty-six women in established labour received epidural analgesia with 0.1% bupivacaine and 2 microg/ml fentanyl. Tympanic membrane (core) temperature was measured every 30 min during labour. There was no significant overall rise in maternal temperature during labour with the use of an ambulatory epidural mixture. One patient exhibited an increase in temperature of 0.8 degrees C to 38 degrees C after 720 min and another of 1.1 degrees C to 38.1 degrees C after 630 min. We conclude that, whilst overall maternal temperature does not increase following low-dose epidural analgesia, individual increases may still occur after 10 h.

Ambulatory labor analgesia: what does an obstetrician need to know?

A simple statement that describes the degree of the patient's satisfaction with the pain relief from her labor epidural analgesia has often assessed the quality of labor analgesia as perceived by the patient. Many laboring parturients, midwives, obstetricians and anesthesiologists are increasingly concerned by the limitations of traditional epidural labor analgesia. In general, women dislike the inability to void, the often-dense motor block, the feeling of numbness of the lower body, the total lack of the urge to bear down, and the complete perineal anesthesia. Continuous search for balanced labor analgesia that provides relief from pain, while preserving motor function, has led to the development of an ambulatory labor analgesia technique. This article assesses the validity of various strongly advocated opinions as to whether parturients benefit from ambulation in labor and also reviews the current trends in ambulatory labor analgesia.

A randomised controlled trial of fluid pre-loading before low dose epidural analgesia for labour

Preloading with fluid is recommended before regional block in labour. Low dose epidurals may produce less haemodynamic disturbance than traditional stronger solutions of local anaesthetics. Our aim was to compare the incidence of hypotension in normal labouring women who received a low dose epidural (0.1% bupivacaine 15 mL with fentanyl 2 microg microg.mL(-1)) with and without an i.v. crystalloid preload. Women with normal labours were randomised to the intervention group: no i.v. crystalloid preload (n = 85) and the control group: 7 mL mL.kg(-1) i.v. crystalloid solution before epidural injection (n = 83). Mean arterial pressure was recorded every 5 min for 30 min. There was no difference between the groups in mean decrease in mean arterial pressure and similar proportions of women showed falls in mean arterial pressure of 20% or greater (13% vs. 11%, risk ratio 1.2, 95% CI 0.54 to 2.8, P = 0.6). Blinded analysis by independent obstetricians revealed no differences in the fetal heart rate abnormalities (20% vs. 15%, risk ratio 1.3, 95% CI 0.67 to 2.7). A scientifically valid conclusion whether preloading is useful cannot be drawn from this study. This study suggests that about 350 participants in each group would be necessary to exclude a type 2 error in a future study.

Does the use of low dose bupivacaine/opioid epidural infusion increase the normal delivery rate?

To investigate whether using low dose epidural infusion improves the normal delivery rate, outcome of labour was studied in women with singleton vertex presentations randomised to receive either 0.0625% bupivacaine opioid, or plain bupivacaine 0.125% for labour. The infusion rate was titrated to maintain analgesia and a sensory level to T10. Data were analysed using the unpaired t test, Mann-Whitney U test and for categorical variables chi2 test. Adjusted odds ratios for factors significantly associated with non-normal delivery were calculated using stepwise logistic regression. There were 291 women in the low dose and 296 in the plain bupivacaine group. There were no significant differences between groups in parity, race, induction of labour, use of augmentation, cervical dilatation at epidural insertion, duration of any stage of labour or duration or volume of infusion. Total dose of bupivacaine (126 +/- 47 mg versus 91 +/- 32 mg) and the proportion of women with motor block at the end of labour (45% versus 27%) were significantly greater in the plain bupivacaine than in the low dose group (P < 0.0001). The adjusted odds ratios (95% CI) for factors significantly associated with non-normal delivery were primiparity: 4.68 (2.78-7.88), older maternal age: 1.1 (1.05-1.14), longer active second stage of labour: 1.01 (1.005-1.017), total bupivacaine dose: 1.01 (1.005-1.016) and greater cervical dilatation at epidural insertion 1.22 (1.08-1.37). Treatment group and motor block at the end of labour had no significant effect. We found no increase in normal delivery rate with low dose infusions.

Impact study of the introduction of low-dose epidural (bupivacaine 0.1%/fentanyl 2μg.mL−1) compared with bupivacaine 0.25% for labour analgesia

We conducted a retrospective analysis of the obstetric effects of introducing a low-dose epidural regimen for epidural analgesia in labour. Before this, all women in our unit requesting epidural analgesia for labour received intermittent boluses (10 mL) of 0.25% bupivacaine. After the introduction of the low-dose service in March 2000, intermittent boluses (10 mL) of 0.1% bupivacaine with fentanyl 2 microg . mL(-1) were given. The records of 300 women were examined, 150 who had received the standard regimen before the introduction of the new service and 150 women afterwards. The groups were compared for outcome of labour, quality of analgesia and any adverse events related to the epidural analgesia. There was a significant reduction in the low-dose group in the number of women requiring instrumental delivery (41% vs. 29%, P = 0.04). The need for indwelling bladder catheters was also reduced in the patients receiving the low-dose regimen (21.3% vs. 4.7%, P < 0.001). Duration of analgesia was longer in patients receiving bupivacaine 0.25% (mean minimum time between boluses 42.25 +/- 33.8 vs. 24.37 +/- 19.8 min, P < 0.001). The need for further anaesthetic intervention was higher with the low-dose regimen (24% vs. 34%, P = 0.037). Maternal satisfaction was high in both groups (95 and 97%, respectively). We conclude that the introduction of a low-dose regimen of epidural analgesia for labour reduces the incidence of instrumental deliveries. It also decreases the incidence of bladder catheterisation during labour, but the need for anaesthetic intervention may be greater.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.

Continuous epidural analgesia with bupivacaine 0.125% or bupivacaine 0.0625% plus sufentanil 0.25 μg·mL−1: a study in singleton breech presentation

Epidural analgesia is the most efficient technique for labor pain relief. However, its resultant motor block might impair the mode of delivery, particularly in breech presentation where the risk of dystocia is high. In this trial, we compared bupivacaine 0.125% with a combination of a low concentration of bupivacaine (0.0625%) and sufentanil (0.25 microg.mL(-1)) both administered by continuous infusion. Analgesia, maternal and fetal/neonatal side effects and obstetric outcome were compared between group bupivacaine (n = 23) and group bupivacaine-sufentanil (n = 35). A greater number of patients in the bupivacaine 0.125% group required more than two top-ups (32 vs. 8% of patients, P = 0.03) while pain scores were similar. Motor block at delivery was more pronounced in the bupivacaine 0.125% group. Nausea and pruritus were more often encountered in the bupivacaine-sufentanil group. There was a trend toward a decreased rate of assisted or operative delivery in the bupivacaine-sufentanil group (92% vs. 74%, P = 0.09). Fetal/neonatal data did not differ between groups. Epidural analgesia with bupivacaine-sufentanil required fewer additional top-ups and produced less motor block than did bupivacaine 0.125%. However, there was no significant difference in mode of delivery between the two analgesic regimens.

Intrathecal ropivacaine or bupivacaine with fentanyl for labour

Combined spinal-epidural (CSE) is widely used to provide pain relief in labour while minimizing motor blockade. Aiming to further reduce associated motor weakness, we compared ropivacaine 2.5 mg in the intrathecal injection with a standard bupivacaine CSE in a double-blind study. Forty women were randomized to receive either bupivacaine 2.5 mg or ropivacaine 2.5 mg intrathecally, both with fentanyl 0.025 mg. There were no significant differences between the groups regarding the onset, duration or quality of analgesia or the level of sensory block attained. Forty per cent of the women (8/20) receiving bupivacaine developed detectable motor block compared with only 5% (1/20) in the ropivacaine group (P<0.05). Vibration sense was impaired in one woman in each group. Adverse effects did not differ between groups. We conclude that intrathecal ropivacaine 2.5 mg in combination with fentanyl 0.025 mg as part of a CSE technique provides rapid and safe analgesia for labour as effective as that achieved with bupivacaine 2.5 mg and with significantly less motor block.

Effect of low-dose mobile versus traditional epidural techniques on mode of delivery: a randomised controlled trial

BACKGROUND

Epidural analgesia is the most effective labour pain relief but is associated with increased rates of instrumental vaginal delivery and other effects, which might be related to the poor motor function associated with traditional epidural. New techniques that preserve motor function could reduce obstetric intervention. We did a randomised controlled trial to compare low-dose combined spinal epidural and low-dose infusion (mobile) techniques with traditional epidural technique.

METHODS

Between Feb 1, 1999, and April 30, 2000, we randomly assigned 1054 nulliparous women requesting epidural pain relief to traditional (n=353), low-dose combined spinal epidural (n=351), or low-dose infusion epidural (n=350). Primary outcome was mode of delivery, and secondary outcomes were progress of labour, efficacy of procedure, and effect on neonates. We obtained data during labour and interviewed women postnatally.

FINDINGS

The normal vaginal delivery rate was 35.1% in the traditional epidural group, 42.7% in the low-dose combined spinal group (odds ratio 1.38 [95% CI 1.01-1.89]; p=0.04); and 42.9% in the low-dose infusion group (1.39 [1.01-1.90]; p=0.04). These differences were accounted for by a reduction in instrumental vaginal delivery. Overall, 5 min APGAR scores of 7 or less were more frequent with low-dose technique. High-level resuscitation was more frequent in the low-dose infusion group.

INTERPRETATION

The use of low-dose epidural techniques for labour analgesia has benefits for delivery outcome. Continued routine use of traditional epidurals might not be justified.

Intrathecal alfentanil with and without bupivacaine for analgesia in labour

Combined spinal-epidural (CSE) for analgesia in labour is widely used as a method of providing pain relief while minimising motor blockade. Aiming to further reduce the associated motor weakness, we investigated the use of alfentanil alone as the initial intrathecal injection in a double-blind study. Thirty women were randomly allocated to receive either alfentanil 0.25 mg with bupivacaine 2.5 mg intrathecally, or alfentanil 0.25 mg in the same volume. Onset of analgesia did not differ significantly between groups but duration was significantly longer in those receiving alfentanil-bupivacaine (mean 55 min vs. 40 min; p < 0.05). Quality of analgesia was satisfactory for all women, although the cumulative analgesia scores were significantly lower in the women receiving the alfentanil-bupivacaine mixture (p = 0.003). More women in the alfentanil-bupivacaine group developed both a sensory level (15/15 vs. 6/15; p < 0.01) and sympathetic block (12/15 vs. 4/15; p < 0.01). Sixty per cent of women receiving the alfentanil-bupivacaine mixture demonstrated an impaired ability to straight leg raise compared with none of the women in the alfentanil-saline group (p < 0.01). The incidence of adverse effects in mother and fetus was similar in both groups. We conclude that intrathecal alfentanil 0.25 mg alone as part of a CSE technique provides rapid analgesia of satisfactory quality without detectable motor blockade.

Comparison of maternal satisfaction between epidural and spinal anesthesia for elective Cesarean section

PURPOSE

Epidural anesthesia was a commonly used technique for elective Cesarean section. Recently, because of the availability of non-cutting spinal needles, many institutions have changed from epidural to spinal anesthesia. The purpose of this study was to compare maternal satisfaction between epidural and spinal anesthesia for elective Cesarean section with a new satisfaction tool.

METHODS

We studied healthy parturients in a randomized, double-blinded pilot study in which patients were assigned to receive either epidural (n = 13) or spinal (n = 14) anesthesia for elective Cesarean section. Two and 24 hr postoperatively, patients completed a validated 22-point maternal satisfaction questionnaire and a 10-cm visual analog score (VAS) for satisfaction. Maternal satisfaction scores were compared between groups.

RESULTS

There was no difference in demographics, complications or technical failures between groups. Mean satisfaction scores on the questionnaire (0-154) at two and 24 hr were 130.23 +/- 11.36 and 129.54 +/- 16.70 for the epidural group and 116.92 +/- 18.47 and 115.92 +/- 15.71 for the spinal group (P = 0.04 and P = 0.03 respectively). No difference in VAS scores was noted. The presence of minor side effects including pruritus contributed to the lower satisfaction in the spinal group at 24 hr.

CONCLUSION

This pilot study demonstrated higher maternal satisfaction with epidural than with spinal anesthesia for elective Cesarean section. This may be related to the increased side effects caused by neuraxial morphine. The satisfaction questionnaire was able to elucidate differences not detected with a global VAS for satisfaction. Further study with a larger patient population is required to confirm these data.

Does an inflatable obstetric belt facilitate spontaneous vaginal delivery in nulliparae with epidural analgesia?

OBJECTIVE

To assess whether an inflatable obstetric belt, synchronised to apply uniform fundal pressure during a uterine contraction, reduces operative delivery rates when used in the second stage of labour.

DESIGN

Randomised controlled trial.

METHODS

Five hundred nulliparae with a singleton cephalic pregnancy at term and with an epidural in labour were recruited during the first stage and randomised at full dilatation. Standard care involved one hour passive second stage and one hour active pushing after which instrumental delivery was performed if delivery was not imminent. Those randomised to the belt group, in addition to standard care, had the inflatable obstetric belt for the whole second stage of labour.

MAIN OUTCOME MEASURE

Mode of delivery.

RESULTS

One hundred and eleven of the 260 women in the belt group (42.7%) compared with 94 of the 240 in the control group (39.2%) had a spontaneous vertex delivery (P = 0.423). The lift-out instrumental delivery rate was similar between the two groups: 108 belts (41.5%), compared with 101 controls (42.1%) (P = 0.902), whereas rotational instrumental deliveries in the belt group were 26 belts (10%) compared with 36 controls (15%) (P = 0.09). Fifteen women (5.8%) in the belt group and nine women (3.8%) in the control group had a caesarean section in the second stage (P = 0.292). An intact perineum was more likely in the belt group (16.5% compared with 9.6%, P = 0.022) as was a third degree tear (6.5% compared with 0.4%, P = 0.001).

CONCLUSION

The inflatable obstetric belt did not significantly reduce operative delivery rates when used in this clinical setting in the second stage of labour.

The development of a maternal satisfaction scale for caesarean section

Satisfaction has become an important outcome measure. The purpose of this study was to develop a valid, reliable maternal satisfaction scale for women undergoing caesarean section. After Research Ethics Board approval, each patient gave verbal consent. To ensure face validity, patients were interviewed before and after caesarean section. Interviewing until no new items were generated ensured content validity. A draft scale using a 7 point Likert scale was given to 115 patients. Items endorsed by less than 15% of patients were deleted. Item-total correlations, principal component and factor analysis were performed and items in factors with less than three items or complex loadings excluded. Correlating the new scale to a Visual Analogue Scale (VAS) for satisfaction assessed construct validity. Reliability, as measured by internal consistency, was tested using Cronbach's alpha. Twenty-five women were interviewed for item generation. Patients were both nulliparous and multiparous and all received regional anaesthesia for elective or non-emergent caesarean section. Six items of the 33 on the draft scale were excluded because of lack of endorsement. Five items were excluded after principal component and factor analysis and two after item-total correlations. The correlation between the scale total and the VAS was 0.48. Cronbach's alpha was 0.82 for the total scale. Maternal sense of control was the item most related to satisfaction. This scale provides more detailed information than a simple VAS. In the population studied, this tool was found to be a valid and reliable method for assessing maternal satisfaction in women undergoing non-emergent caesarean section.

A survey of epidural analgesia for labour in the United Kingdom

A postal survey of obstetric units throughout the UK was conducted to obtain information about the provision of epidural analgesia for labour. Ninety per cent of units offered a 24-h epidural service and the average epidural rate was 24%. The most commonly administered epidural test dose was 3 ml of bupivacaine 0.5% and bupivacaine 0. 25% was most often used as the initial epidural top-up. Continuous infusions of low-dose bupivacaine and opioid mixtures were the most popular method of maintenance epidural analgesia. Twenty-four per cent of units offered combined spinal-epidural analgesia in addition to standard epidural analgesia. Midwives played a prominent role in the administration of epidural bolus top-ups and also in the assessment and maintenance of continuous epidural infusions.

Regional analgesia in early active labour: combined spinal epidural vs. epidural

We randomly allocated 93 women in early active labour and requesting epidural analgesia to receive either epidural (n = 48) or combined spinal-epidural analgesia (n = 45). For epidural analgesia 15 ml of bupivacaine 0.1% with 75 micrograms of fentanyl were injected into the epidural space. For combined spinal-epidural analgesia 1 ml of bupivacaine 0.25% with 25 micrograms of fentanyl were injected into the subarachnoid space. For both groups subsequent top-ups of 10 ml of bupivacaine 0.1% with fentanyl 20 micrograms were given using a lightweight patient-controlled epidural analgesia (PCEA) pump with a lockout time of 30 min. We assessed analgesia and the degree of motor blockade and found no significant differences in pain or maternal satisfaction scores between the two groups. The time to first top-up was significantly longer in the epidural group than in the CSE group (p = 0.01). The combined spinal-epidural group had significantly greater motor blockade at 30 min than the epidural group (p = 0.01), but there was no difference after this. The PCEA machine failed completely twice and temporarily many times. We conclude that the combined spinal-epidural technique confers no advantages in early active labour. Also, a lightweight PCEA pump needs to be more reliable before we can recommend its use.

Maternal satisfaction with labour analgesia

Satisfaction with childbirth is a multidimensional issue, of which analgesia is but one component. The importance of analgesia as a contribution to overall satisfaction has been recognized increasingly in the last 50 years, but improvement in quality of available analgesia has not always resulted in commensurate improvement in satisfaction. Satisfaction by its very nature has proved to be difficult both to define and to quantify, and no reliable standards of measurement have been accepted. Pain relief in childbirth is subject to many social and cultural modifiers, which continue to change. Control of pain rather than absolute amelioration is seen by many to provide greater satisfaction. Analgesia issues still do not figure prominently in the overall satisfaction of the birthing process for the vast majority of women, despite the availability of and demand for improved methods of relief. The interpersonal relationships established between patient and healthcare providers may ultimately be of more importance in the determination of satisfaction with management.

Alternating patient position following the induction of obstetric epidural analgesia does not affect local anaesthetic spread

To assess the influence of gravity on epidural-induced sensory blockade during the first stage of labour, 60 parturients were recruited to a randomized, controlled, single-blinded study. In all cases an epidural catheter was placed with the patient in the left lateral position. Thereafter, patients were randomized to one of three groups. In group supine (S), the epidural injection was performed in the supine position with a 15-20 degrees right flank elevation and the patient remained supine. In group left (L) patients remained in the left lateral position for 10 min after injection. In group left and right (L+R) patients remained in the left lateral position for 5 min and then assumed the right lateral position for 5 min. Thereafter, in groups L and L+R patients lay supine with a 15-20 degrees right flank elevation. All patients received 50 microg fentanyl in 10 ml of 0.125% bupivacaine. Ten minutes after injection loss of pinprick and temperature sensation were assessed and pain scores measured. Height of sensory deficit 10 min after injection and after maximal blockade were unaffected by patient position. In all cases maximal blockade reached T8 or higher. Time to maximal block was 14.7 +/- 2.3 min, 14.1 +/- 1.6 min and 13.9 +/- 1.5 min for groups L, L+R and S respectively. After maximal blockade, pain scores were significantly (P<0.0001) decreased in all groups, with no differences between them. We conclude that position immediately following local anaesthetic drug administration has little effect on onset and distribution of epidural analgesia.

Blood pressure and fetal heart rate changes with patient-controlled combined spinal epidural analgesia while ambulating in labour

OBJECTIVE

To determine the effect of patient-controlled combined spinal epidural analgesia (PCEA) on maternal pulse and blood pressure, and fetal heart rate in primigravid women, when adapting different positions in labour.

DESIGN

A prospective study.

SETTING

Queen Charlotte's and Chelsea hospital, London.

PARTICIPANTS

Fifty-five primigravid women in labour at > or = 37 weeks of gestation; 40 women had supervised standing top-ups given by an anaesthetist. A further 15 women had PCEA top-ups given in each of standing, sitting and lying positions.

MAIN OUTCOME MEASURES

Maternal pulse rate, blood pressure and fetal heart rate changes following epidural top-ups.

RESULTS

In the first 40 women there was no clinically significant fall in their blood pressure (< 5 mmHg). The subsequent 15 women who had PCEA top-ups had no fall in blood pressure in the standing and sitting positions, though the average blood pressure fell significantly when a top-up was given in the lying position. Maternal heart rate increased significantly at 12 min post top-up when the women were in the standing position (P = 0.0018). In the 15 women who had PCEA top-ups, the CTG showed improvement in decelerations when women were in the standing position but deterioration when in the lying position (P < 0.01).

CONCLUSION

Patient-controlled epidural analgesia top-ups with maternal mobility may be beneficial to the fetus possibly by reducing the hypotension normally associated with top-ups in the lying position.

Comparison of 15 mg and 25 mg of bupivacaine both with 50 μg fentanyl as initial dose for epidural analgesia

Bupivacaine 15 mg is commonly used as a test dose prior to the initial dose for epidural analgesia in labour. When 15 mg or 25 mg of bupivacaine (15 ml of 0.1% or 0.167%) with 50 microg fentanyl was administered blindly to two groups of labouring women, as an initial dose, 83% and 90% of women respectively, achieved analgesia within 20 min. All the remaining women achieved analgesia with a further dose of 10 mg bupivacaine (10 m10.1%) with fentanyl 2 microg per ml given at 20 min.

Epidural analgesia for labour and delivery: fentanyl or sufentanil?

PURPOSE

The highly lipid soluble opioids, fentanyl and sufentanil, are used in combination with local anaesthetics with/without epinephrine to provide epidural analgesia during labour and delivery. Our aim was to determine whether wither opioid was superior when used with low dose local anaesthetic.

METHODS

In a double-blind study patients were randomized to two epidural infusion groups: Group I (n = 50) fentanyl 2 micrograms.ml-1 with bupivacaine 0.015% and epinephrine 2 micrograms.ml-1, Group II(n = 50) sufentanil 1 microgram.ml-1 with bupivacaine 0.015% and epinephrine 2 micrograms.ml-1. Following a 20 ml bolus of the study solution an infusion was started at 10 ml.h-1. To achieve analgesia patients could receive two boluses of 5 ml of the study solution and if analgesia was still inadequate, a further 5 ml bupivacaine 0.25% was used. Pain and overall satisfaction were assessed with a 10-point visual scale. Plasma samples obtained from the mother at the time the infusion was discontinued and from the umbilical cord vein at delivery were assayed to determine opioid concentration.

RESULTS

Pain scores were greater for Group I than for Group II patients throughout the first and second stages of labour (P = 0.002). More patients in Group I (42%) requested a dose of bupivacaine 0.25% than in Group II (6%) (P < 0.001) and the total dose of bupivacaine given to Group I patients was greater than that of Group II, 26.0 +/- 22.0 mg vs. 13.4 +/- 12.6 mg, P = 0.005. There were no differences with respect to first or second stage duration, incidence of side effects, infusion duration, outcome of labour or neonatal Apgar scores. There was no opioid accumulation in either maternal or foetal blood.

CONCLUSION

Epidural opioid infusion with very low dose bupivacaine (0.015%) achieved an overall high level of patient satisfaction in both groups without serious maternal or neonatal side effects. At the fentanyl-to-sufentanil ratio used here patients receiving sufentanil had lower pain scores and substantially fewer patients required bupivacaine rescue.

Adding fentanyl 0.0002% to epidural bupivacaine 0.125% does not delay gastric emptying in laboring parturients

Previous studies have shown that bolus doses of fentanyl (50 and 100 micrograms) with epidural bupivacaine delay gastric emptying by up to 45 min. We studied the effect of the addition of small-dose fentanyl to epidural bupivacaine infusions on gastric emptying during labor. The acetaminophen absorption technique was used to infer gastric emptying. Twenty-eight patients in established labor consented to participate in the study. They were randomized to receive either 1) 10 mL bupivacaine 0.125% followed by an infusion of 0.125% bupivacaine at 10 mL/h or 2) 10 mL bupivacaine 0.125% with 50 micrograms fentanyl followed by an infusion of 0.125% bupivacaine and 0.0002% fentanyl at 10 mL/h. Two hours after initiation of epidural analgesia, each patient ingested 20 mg/kg acetaminophen in a suspension of 150 mL water. Venous blood samples were drawn for a baseline and then every 15 min for 2 1/2 h. There were no significant demographic differences between the groups. There were no differences detected between groups in the peak plasma concentrations of acetaminophen, the time to achieve the peak plasma concentrations, or the area under the curve at 45 and 90 min. Our results indicate that epidural infusions for labor analgesia using 0.125% bupivacaine and 0.0002% fentanyl do not delay gastric emptying compared to infusions of bupivacaine 0.125% alone.

Epidural infusion of low-dose bupivacaine and opioid in labour. Does reducing motor block increase the spontaneous delivery rate?

Labouring women were randomly allocated to receive epidural infusions during labour of either 0.125% plain bupivacaine (n = 200) or a combination of 0.0625% bupivacaine with either 2.5 micrograms.ml-1 fentanyl or 0.25 micrograms.ml-1 sufentanil (n = 199) each starting at 12 ml.h-1 and adjusted as necessary to maintain analgesia. The dose of bupivacaine, both hourly (p < 0.001) and total (p < 0.001), was significantly lower in the group receiving the combination. Motor block was significantly less common and less severe in the combination group (p < 0.001). These reductions did not result in a significant increase in spontaneous deliveries. Maternal satisfaction with first (p < 0.001) and second stage analgesia (p < 0.001) was significantly increased in the combination group. The addition of opioid to the epidural infusion did not reduce the incidence of perineal pain. There were no significant differences between the groups in neonatal outcome or the incidence of early postnatal symptoms.