Ropivacaine and Fentanyl Concentrations in Patient-Controlled Epidural Analgesia During Labor: A Volume-Range Study

Labor Analgesia Initiation With Dural Puncture Epidural Versus Conventional Epidural Techniques: A Randomized Biased-Coin Sequential Allocation Trial to Determine the Effective Dose for 90% of Patients of Bupivacaine

BACKGROUND

The dural puncture epidural (DPE) technique has a faster onset, better sacral spread, and improved bilateral coverage when compared to the conventional epidural (EPL) technique. Whether these qualities translate into a lower bupivacaine dose to provide initial analgesia is unknown. We sought to determine the effective dose of bupivacaine to achieve initial (first 30 minutes) labor analgesia in 90% of patients (ED90) with the DPE and EPL techniques, using a biased-coin, sequential allocation method.

METHODS

A total of 100 women of mixed parity with term, singleton gestation at ≤5 cm dilation with no major comorbidities were randomized to receive a DPE or an EPL technique. An experienced anesthesiologist performed these techniques and administered an allocated dose of plain bupivacaine diluted with isotonic sterile 0.9% saline to a total volume of 20 mL via the EPL catheter. Bupivacaine doses for each subject were determined by the response of the previous subject, using a biased-coin sequential allocation method, with success defined by a numeric rating scale (NRS) < 3 at 30 minutes. Outcome assessments were performed by an investigator blinded to the technique and bupivacaine dose. Sensory and motor blockade and maternal or fetal side effects were recorded every 5 minutes for the first 30 minutes. The ED90 of bupivacaine with each technique was estimated using centered isotonic regression.

RESULTS

A total of 95 women were included in the final analysis. The ED90 of bupivacaine was estimated at 29.30 mg (90% confidence interval [CI], 28.55-31.56) with a DPE technique and 45.25 mg (90% CI, 42.80-52.03) with an EPL technique.

CONCLUSIONS

Using a biased-coin, sequential allocation method, the DPE technique requires less bupivacaine to achieve effective initial analgesia (ED90) when compared to the EPL technique.

Dural puncture epidural versus conventional epidural analgesia for labor: a systematic review and meta-analysis of randomized controlled studies

Dural puncture epidural (DPE) technique is a modification of the conventional epidural (EP) technique in that the dura is intentionally punctured with a spinal needle but without any spinal injection. This meta-analysis aimed to evaluate the benefits and risks associated with the DPE technique for labor analgesia. Randomized trials comparing DPE analgesia with EP analgesia for labor pain relief were systematically searched in the database of Medline, Embase, Cochrane Controlled Trials Register, Web of Science, and China Biology Medicine till 1^st August 2021. The primary outcome was the percentage of patients with satisfactory pain relief following DPE or EP analgesia, which was defined as visual analog scale (VAS) pain scores ≤ 3/10 (or 30/100) measured 10 min and 20 min after initiation of labor analgesia. Totally ten trials with 1099 patients were included in this review. DPE technique increased the percentage of patients with VAS pain score ≤ 3/10 (or 30/100) both at 10 min (RR 1.43; 95% CI 1.17, 1.74; p < 0.001; I² = 0%) and 20 min (RR 1.13; 95% CI 1.04, 1.22; p = 0.005; I² = 0%) after labor analgesia. No adverse event was found with DPE analgesia. We conclude that compared with EP analgesia, DPE analgesia is beneficial for labor pain relief by shortening the time to achieve satisfactory pain control. Meanwhile, DPE analgesia is not associated with increased adverse maternal/fetal events.

Effects of different epidural initiation volumes on postoperative analgesia in cesarean section

Background/aim

The aim of this study was to compare the effects of different epidural initiation volumes on postoperative pain scores, analgesic requirements, and side effects in pregnant women administered patient-controlled epidural analgesia (PCEA) for postoperative pain after cesarean sections.

Materials and methods

Eighty-one pregnant women, aged 18–45 years, were included in this randomized, double-blind study. Combined spinal epidural anesthesia was administered for each cesarean section. The patients were divided into 3 groups and different volumes (20 mL, 10 mL, and 5 mL) of the study drug (0.0625% bupivacaine plus 2 μg/mL of fentanyl) were administered 90 min after the spinal block via epidural catheter. The visual analogue scale (VAS) scores at rest and during movement, first PCEA dose time, number of PCEA doses required per hour, total analgesic consumed, and side effects were recorded postoperatively.

Results

There were no statistically significant differences among the groups in terms of the VAS rest and VAS movement scores. The times to the first analgesic dose requirement were longer in Group 10 and Group 20 than in Group 5. The analgesic requirement during the first 2 h was lower in Group 20 than in the other groups.

Conclusions

The PCEA initiations with different volumes provided similar pain scores. However, the 20 mL volume resulted in a lower analgesic dose requirement during the early postoperative period, and it also delayed the requirement for analgesia.

Are there differences in pain intensity between two consecutive vaginal childbirths? A retrospective cohort study

BACKGROUND

Pain assessment is crucial for in-labour pain management. Even though women's self-rated pain intensity is the standard for pain relief or analgesic administration, multiparas appear to receive worse in-labour pain management than primiparas do. The discrepancy in pain perception between primiparas and multiparas remains unclear. Healthcare providers tend to think that multiparas endure the pain and report less pain because they have experienced childbirth.

OBJECTIVE

To retrospectively analyse the intensity of in-labour pain during first and second vaginal childbirth within the same group of women and explore whether parity may be an influential factor in labour pain intensity.

DESIGN

Retrospective cohort study.

SETTING

Labour and delivery in a large academic specialized hospital in Guangzhou, China.

PARTICIPANTS

Women were included if they had two consecutive vaginal childbirths with singleton cephalic presentations and cervical dilation ≤ 3 cm for the first childbirth and ≤ 2 cm for the second childbirth. The final study sample consisted of 417 women.

METHODS

All childbirth case records between January 2015 and August 2018 were scanned using a structured electronic medical system. Maternal and neonatal demographics as well as obstetric and neonatal outcomes were extracted. The in-labour pain for each childbirth was compared between first and second births. Paired t-tests, McNemar's chi-square tests and mixed-effects modelling were applied to compare the differences in labour pain intensity between the two vaginal childbirths and explore the factors that influenced maximum labour pain scores during the second childbirth.

RESULTS

Four hundred seventeen women were included, with an average birth interval of 1.7 years. The average maximum labour pain score during the latent phase was 6 (5,6) for the first childbirth and 5 (4,6) for the second childbirth (paired t =-6.13, P <0.001). Pain scores decreased in 28.1% (117/417) of women and increased in 13.7% (57/417) of women from the first to the second childbirth. More than half of the women in our study experienced the same maximum labour pain score during the first and second labour. Mixed-effects modelling revealed that parity, education and pregnancy complications were independently associated with maximum labour pain scores.

CONCLUSIONS

From a clinical point of view, in-labour pain is not clinically different for women when comparing their first and second labours. Health care professionals may underestimate in-labour pain in primiparas when comparing them with nulliparas. More studies are warranted to explore options for achieving better pain management for women with more childbirths.

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.

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.

A randomised double-blinded controlled trial of the effect of diluent volume on the efficacy of a single dose of epidural ropivacaine for labour analgesia

BACKGROUND

Few studies have systematically investigated the effect of diluent volume on the efficacy of epidural local anaesthetics for labour analgesia and no data are available for ropivacaine. Our aim was to compare epidural ropivacaine given in three different volumes for labour analgesia.

METHODS

In a double-blinded study, we randomly assigned 60 labouring parturients with cervical dilatation <5 cm to receive epidural ropivacaine 30 mg diluted to 5 mL (group 5, n=20), 10 mL (group 10, n=20) or 20 mL (group 20, n=20) for analgesia. We measured visual analogue scale pain scores at the peak of contraction for 30 min plus onset and duration of analgesia.

RESULTS

Pain scores at 30 min were similar among group 5 (median 22 [interquartile range 0-44] mm), group 10 (9 [0-21] mm) and group 20 (37 [0-51] mm), P=0.35. The number of patients who achieved a decrease in pain score to < or =30% of baseline was similar among group 5 (12/20 (60%)), group 10 (17/20 (85%)) and group 20 (11/19 (58%)), P=0.13. Onset and duration of analgesia, the incidence of motor block and patient satisfaction were similar among groups.

CONCLUSIONS

Under the conditions of this study, within the range of 5-20 mL, the volume and concentration were not significant factors influencing the efficacy of a single 30-mg bolus of epidural ropivacaine given for labour analgesia. This suggests that the most important factor influencing analgesic efficacy was drug mass.

[Patient-controlled epidural analgesia for labour: in practice]

OBJECTIVES

Update on patient controlled epidural analgesia for labour.

STUDY DESIGN

Literature review of the recent data on local anaesthetics, additional analgesics and of publications on the various protocols used.

DATA COLLECTION

Pubmed database was checked with the following key words: PCEA, labour, opioids, clonidine. The abstracts of the ASA meetings from 2000 to 2005 were also examined.

RESULTS

Patient controlled epidural analgesia (PCEA) is the method of choice for optimal labour pain management. The advantages of this technique are numerous. Some of them are established: consistent reduction in overall local anathetic requirement, less motor blockade, safety of the technique and team workload reduction. A better adequacy with the analgesic requirements and an increase in overall patient satisfaction are frequently retrieved, provided that the choice of the analgesics and the PCEA parameters are adequately chosen.

CONCLUSION

The use of PCEA improves the quality of analgesic management offered to the parturients who are more and more willing to have a "more natural" childbirth. The PCEA gives them more autonomy and, in fine, enables them to better enjoy this unique event. The main barrier to a more widespread diffusion of PCEA in many institutions remains the financial issue, although a well-selected device and low cost disposables allow a reduction of indirect costs by decreasing care giver workload.

Recent advances in patient-controlled epidural analgesia for labour

PURPOSE OF REVIEW

Patient-controlled epidural analgesia (PCEA) is a relatively new mode of maintenance of labour analgesia. The purpose of this review is to demonstrate that PCEA has several advantages over continuous-infusion analgesia and to discuss recent refinements in the use of PCEA for labour.

RECENT FINDINGS

Early investigations showed that PCEA without background infusion reduced the incidence of motor block and the amount of local anaesthetic needed to produce satisfactory analgesia compared to continuous infusions. Recent studies have shown that the addition of a background infusion to PCEA may be advantageous, depending on the patient population and the rate of the continuous infusion. Both bupivacaine and ropivacaine have been used in PCEA but ropivacaine may be associated with a reduced incidence of motor block in parturients who have epidural analgesia for long periods of time. Of note, very low concentrations of local anaesthetics are required to produce satisfactory analgesia.

SUMMARY

PCEA has proven to be a safe, convenient, and highly effective way to maintain labour analgesia. Parturients appreciate the control they have over the analgesia received throughout labour when this method is used.