A Systematic Review and Meta-Analysis Comparing Programmed Intermittent Bolus and Continuous Infusion as the Background Infusion for Parturient-Controlled Epidural Analgesia

An Innovative Approach to Determine Programmed Intermittent Epidural Bolus Pump Settings for Labor Analgesia: A Randomized Controlled Trial

BACKGROUND

Three settings are required on a programmed intermittent epidural bolus (PIEB) pump for labor analgesia: the PIEB next bolus (PIEBnb), PIEB interval (PIEBi), and PIEB volume (PIEBv). The ideal settings for these parameters are still unknown. We hypothesized a mathematical modeling tool, response surface methodology (RSM), could estimate 3 PIEB pump parameters while balancing 3 clinically important patient outcomes simultaneously. The study objective was to use RSM to estimate PIEB settings (PIEBnb, PIEBi, and PIEBv) while maximizing maternal satisfaction, minimizing the need for clinician-administered boluses, and optimizing the ratio of delivered/requested patient-controlled epidural analgesia (PCEA) boluses simultaneously.

METHODS

With institutional ethics approval, a double-blind randomized trial was completed in a tertiary care labor and delivery center. Nulliparous, English-speaking American Society of Anesthesiologists (ASA) physical status II patients aged 18 to 45 years at full term, single gestation in vertex presentation, in spontaneous labor and ≤7 cm cervical dilation were included. Patients with comorbidities, contraindications to neuraxial analgesia, using chronic analgesics, <152 cm, or body mass index (BMI) >45 kg/m 2 were excluded. After informed consent, labor analgesia was initiated using 10 mL ropivacaine 0.2% with 10 µg/mL fentanyl solution and PCEA (volume 6 mL every 10 minutes). Patients were randomized to predetermined PIEB settings. RSM identified 3 pump settings that represented a stationary point that best maximized or minimized 3 outcomes simultaneously: PCEA ratio (a ratio closest to 1), clinician bolus (optimal is 0), and maternal satisfaction (visual analog scale, 0-100, ideal response is ≥90).

RESULTS

Of 287 potential participants, 192 did not meet inclusion criteria or declined to participate, and 26 were withdrawn, leaving 69 patients for study inclusion. Using RSM, the suggested PIEB settings for all the primary study outcomes were as follows: PIEBnb = 29.4 minutes, PIEBi = 59.8 minutes, and PIEBv = 6.2 mL. These PIEB settings corresponded to the following clinical outcomes: maternal satisfaction at 93.9%, PCEA ratio at 0.77, and need for clinician bolus at 0.29. The dermatome sensory score was between T10 and T5 in 89% of the patients. The median lowest Bromage score was 4.

CONCLUSIONS

This novel study used a mathematical model to estimate PIEB pump settings while simultaneously maximizing 3 clinical outcomes. Equally weighted clinical outcomes prevent maximal outcome optimization and may not reflect patient priorities. Future studies or quality improvement endeavors could use RSM methodology to estimate PIEB pump settings targeting optimal values for a single clinical outcome of determined importance to parturients.

Programmed intermittent epidural bolus regimen vs continuous epidural infusion: a retrospective study of motor block and obstetric outcomes using the Robson's Ten Group Classification System

BACKGROUND

Use of a programmed intermittent epidural bolus (PIEB) regimen during labour is associated with several benefits over a continuous epidural infusion (CEI), including reduced local anaesthetic consumption and reduced risk of motor block. We hypothesise that the benefits of a PIEB regimen may vary according to the Robson Ten Group Classification System (TGCS). The aim of this study was to determine if introduction of a PIEB regimen was associated with reduced incidence of motor block. We also wished to examine changes in obstetric outcomes following PIEB introduction across the Robson TGCS.

METHODS

This was a single-centre retrospective cohort study. Data were collected over two three-month periods before and after PIEB introduction. The primary outcome was the incidence of motor block. Maternal and obstetric outcomes across Robson Groups 1-4 were analysed.

RESULTS

Introduction of PIEB was associated with reduced incidence of motor block (28.4% (95% CI 25.7% to 31.3%) vs 22.4%, (95% CI 19.9% to 25.2%), difference 5.9% (95% CI 1.0% to 21.1%), P=0.003), with no association with changes in rates of caesarean section, operative vaginal delivery or other obstetric outcomes. Use of a PIEB regimen was associated with reduced incidence of motor block in Robson Group 4a (20.3% (16.0%, 28.0%) vs 12.0%, (7.6%, 16.4%), difference 9.9% (95% CI -17.4% to -2.4%) P=0.009). There were no significant changes in other outcomes assessed across Robson TGCS.

CONCLUSION

Introduction of PIEB for maintenance of labour analgesia was associated with reduced incidence of motor block in our institution compared with CEI. Presenting results according to Robson's TGCS in future studies may allow better elucidation of the impact of neuraxial analgesia on maternal and obstetric outcomes.

Effects of different neuraxial analgesia modalities on the need for physician interventions in labour: A network meta-analysis

BACKGROUND

Neuraxial labour analgesia can be initiated with epidural (EPL), combined spinal epidural (CSE) or dural puncture epidural (DPE) and maintained with continuous epidural infusion (CEI), patient-controlled epidural analgesia (PCEA) or programmed intermittent epidural bolus (PIEB), but the optimal analgesia modality is still controversial.

OBJECTIVE

To compare the effects of commonly used neuraxial analgesia modalities on the proportion of women needing physician interventions, as defined by the need for physician-administered epidural top-ups for inadequate analgesia in labour.

DESIGN

Bayesian network meta-analysis.

DATA SOURCES

PubMed, Embase, CENTRAL, Web of Science and Wanfang Data were searched from January 1988 to August 2023 without language restriction.

ELIGIBILITY CRITERIA

Randomised controlled trials comparing two or more modalities of the following six neuraxial analgesia modalities in healthy labouring women: EPL+CEI+PCEA, EPL+PIEB+PCEA, CSE+CEI+PCEA, CSE+PIEB+PCEA, DPE+CEI+PCEA and DPE+PIEB+PCEA.

RESULTS

Thirty studies with 8188 women were included. Compared with EPL+CEI+PCEA, EPL+PIEB+PCEA [odds ratio (OR) = 0.44; 95% credible interval (CrI), 0.22 to 0.86], CSE+PIEB+PCEA (OR = 0.29; 95% CrI, 0.12 to 0.71) and DPE+PIEB+PCEA (OR = 0.19; 95% CrI, 0.08 to 0.42) significantly reduced the proportion of women needing physician interventions. DPE+PIEB+PCEA had fewer women needing physician interventions than all other modalities, except for CSE+PIEB+PCEA (OR = 0.63; 95% CrI, 0.25 to 1.62). There were no significant differences in local anaesthetic consumption, maximum pain score, and the incidence of instrumental delivery between the different neuraxial modalities.

CONCLUSIONS

PIEB+PCEA is associated with a lower risk of physician interventions in labour than CEI+PCEA. DPE or CSE and PIEB+PCEA may be associated with a lower likelihood of physician interventions than other neuraxial modalities. Otherwise, the new neuraxial analgesia techniques do not appear to offer significant advantages over traditional techniques. However, these results should be interpreted with caution due to limited data and methodological limitations.

TRIAL REGISTRATION

PROSPERO (CRD42023402540).

The 90% effective concentration of alfentanil combined with 0.075% ropivacaine for epidural labor analgesia: a single-center, prospective, double-blind sequential allocation biased-coin design

PURPOSE

More literature studies have reported that alfentanil is safe and effective for labor analgesia. However, there is no unified consensus on the optimal dosage of alfentanil used for epidural analgesia. This study explored the concentration at 90% of minimum effective concentration (EC90) of alfentanil combined with 0.075% ropivacaine in patients undergoing epidural labor analgesia to infer reasonable drug compatibility and provide guidance for clinical practice.

METHODS

In this prospective, single-center, double-blind study, a total of 45 singleton term primiparas with vaginal delivery who volunteered for epidural labor analgesia were recruited. The first maternal was administered with 3 μg/mL alfentanil combined with 0.075% ropivacaine with the infusion of 10 mL of the mixture every 50 min at a background dose of 3 mL/h. In the absence of PCEA, a total of 15 mL of the mixture is injected per hour. The subsequent alfentanil concentration was determined on the block efficacy of the previous case, using an up-down sequential allocation with a bias-coin design. 30 min after epidural labor analgesia, the block of patient failed with visual analog score (VAS) > 3, the alfentanil concentration was increased in a 0.5 μg/mL gradient for the next patient, while the block was successful with VAS ≤ 3, the alfentanil concentration was remained or decreased in a gradient according to a randomized response list for the next patient. EC90 and 95% confidence interval were calculated by linear interpolation and prediction model with R statistical software.

RESULTS

In this study, the estimated EC90 of alfentanil was 3.85 μg/mL (95% confidence interval, 3.64-4.28 μg/mL).

CONCLUSION

When combined with ropivacaine 0.075%, the EC90 of alfentanil for epidural labor analgesia is 3.85 μg/mL in patients undergoing labor analgesia.

Regional anaesthesia truncal blocks for acute postoperative pain and recovery: a narrative review

Significant acute postoperative pain remains prevalent among patients who undergo truncal surgery and is associated with increased morbidity, prolonged patient recovery, and increased healthcare costs. The provision of high-quality postoperative analgesia is an important component of postoperative care, particularly within enhanced recovery programmes. Regional anaesthetic techniques have become increasingly prevalent within multimodal analgesic regimens and the widespread adoption of ultrasonography has facilitated the development of novel fascial plane blocks. The number of described fascial plane blocks has increased significantly over the past decade, leading to a burgeoning area of clinical investigation. Their applications are increasing, and truncal fascial plane blocks are increasingly recommended as part of procedure-specific guidelines. Some fascial plane blocks have been shown to be more efficacious than others, with favourable side-effect profiles compared with neuraxial analgesia, and are increasingly utilised in breast, thoracic, and other truncal surgery. However, use of these blocks is debated in regional anaesthesia circles because of limitations in our understanding of their mechanisms of action. This narrative review evaluates available evidence for the analgesic efficacy of the most commonly practised fascial plane blocks in breast, thoracic, and abdominal truncal surgery, in particular their efficacy compared with systemic analgesia, alternative blocks, and neuraxial techniques. We also highlight areas where investigations are ongoing and suggest priorities for original investigations.

Programmed Intermittent Intrathecal Bolus for Maintenance of Labor Analgesia in an Obstetric Patient: A Case Report

Maintenance of labor analgesia with programmed intermittent epidural boluses (PIEBs) has demonstrated benefits over the use of continuous infusions. While programmed intermittent boluses have been used for the maintenance of epidural analgesia, it has not been reported for the maintenance of intrathecal analgesia. Approximately 25% of intrathecal catheters (ITC) ultimately fail, often due to inadequate analgesic coverage. We describe the use of programmed intermittent intrathecal boluses for a laboring parturient who received an ITC. She reported excellent pain relief without significant motor block, high anesthetic block, hypotension, or respiratory distress. This delivery modality may increase the rate of ITC after unintentional dural puncture (UDP).

Programmed intermittent epidural bolus in maintenance of epidural labor analgesia: a literature review

Programmed intermittent epidural bolus (PIEB), administered by the infusion pump programmed to deliver boluses of epidural solution at certain intervals, is gradually gaining more attention as a technique to maintain the labor analgesia in recent years. Many studies find that it may have some advantages when compared with other methods. However, its exact effectiveness and optimal regimen are still unclear. We conducted a literature search in PubMed, Web of Science, and Cochrane Database of Systematic Reviews for studies published between January 2010 and June 2022. Of the 263 publications identified, 27 studies were included. The purpose of this review is to discuss the effects of PIEB with continuous epidural infusion (CEI) and patient-controlled epidural analgesia (PCEA) in maintenance of epidural labor analgesia on labor outcomes and elucidate the latest research progress of implementation strategies.

Re: Effect of intrapartum epidural analgesia on rate of emergency delivery for presumed fetal compromise: nationwide registry-based cohort study

Linked article: This Correspondence comments on Damhuis et al. Click here to view the article.

Modern labor epidural analgesia: implications for labor outcomes and maternal-fetal health

Epidural analgesia is an important means of pain control during labor throughout the world. Over its historic development, it has been implicated in several undesirable outcomes, including prolongation of labor and increased need for operative delivery. These effects have emerged in some retrospective and observational studies, but such methods of investigation are highly prone to bias and are particularly ill-suited for the study of labor analgesia. In high-quality studies, including Cochrane reviews and meta-analyses, epidural analgesia has been suggested to extend the first stage of labor by 30 minutes and the second stage by 15 minutes, when compared with alternative forms of analgesia. Although this may be a reproducible effect, it may be argued that it is clinically negligible. With respect to mode of delivery, similar high-quality studies have consistently shown no increased risk of cesarean delivery associated with epidural analgesia. Some forms of epidural analgesia were associated with higher risk of assisted vaginal delivery, but the use of newer modalities has been shown to abolish this effect. Specific advancements have centered on reducing total anesthetic consumption, given that local anesthetic-induced motor block is theorized to interfere with maternal expulsive efforts in the second stage of labor. These measures include the use of low-concentration local anesthetic solutions equivalent to ≤0.1% bupivacaine, shown in meta-analyses to lead to no higher risk of assisted vaginal delivery relative to nonepidural analgesia. Additional advancements in the maintenance of analgesia include programmed intermittent epidural bolus and patient-controlled epidural analgesia, the combination of which has been shown to reduce the risk of assisted vaginal delivery, also likely mediated by reduction in local anesthetic dose. These techniques have gained popularity in the past two decades, such that studies published since 2005 show no higher risk of assisted vaginal delivery with epidural than with opioid analgesia (as reported in a Cochrane review). Labor epidural analgesia has implications for maternal and fetal health perinatally. It is known to result in transient maternal hypotension (particularly with initiation), which may progress to the level of necessitating fluid or vasopressor therapy. This is not clearly associated with any adverse outcomes. There is also a consistently higher incidence of fever in parturients receiving neuraxial anesthesia, likely of noninfectious origin, which has similarly not been associated with adverse neonatal outcomes. Finally, neonates of parturients who receive epidural analgesia have been shown to have no worse Apgar scores and more favorable acid-base status than their counterparts. These observations should serve to reassure providers that modern labor analgesia, as currently understood, is not consistently associated with any significant adverse outcomes for the parturient or fetus. In this review, we describe variations of modern labor epidural analgesia, conduct an in-depth review of current literature on its use, and explore the most up-to-date evidence on its implications for the progression and outcomes of labor, including the pertinent maternal and fetal side effects.

Comparison of different delivery modalities of epidural analgesia and intravenous analgesia in labour: a systematic review and network meta-analysis

PURPOSE

In labour, neuraxial analgesia is the standard in the provision of pain relief. However, the optimal mode of delivering epidural solution has not been determined, and some parturients may need an alternative to epidural analgesia. We sought to conduct a systematic review and network meta-analysis to compare continuous epidural infusion (CEI), programmed intermittent epidural bolus (PIEB), computer-integrated CEI, computer-integrated PIEB, patient-controlled epidural bolus (PCEA), fentanyl patient-controlled analgesia (PCA), and remifentanil PCA, either alone or in combination.

METHODS

We searched CENTRAL, CINAHL, Ovid Embase, Ovid Medline, and Web of Science for randomized controlled trials that included nulliparous and/or multiparous parturients in spontaneous or induced labour. The maintenance epidural solution had to include a low concentration local anesthetic and an opioid. Specific subgroups in the obstetric population such as preeclampsia were excluded. Network meta-analysis was performed with a frequentist method, and continuous and dichotomous outcomes are presented as mean differences and odds ratios, respectively, with 95% confidence intervals.

RESULTS

Overall, 73 trials were included. For the first coprimary outcome, the need for rescue analgesia, CEI was inferior to PIEB and PIEB + PCEA was superior to PCEA alone, with a low certainty of evidence given the presence of serious limitations and imprecision. The second coprimary outcome, the maternal satisfaction, was improved by PIEB + PCEA compared with CEI + PCEA and PCEA alone, with a low quality of evidence in view of the presence of serious limitations and imprecision. Fentanyl PCA increased the requirement for rescue analgesia and decreased maternal satisfaction relative to many methods of delivering epidural solution. In terms of secondary outcomes, PIEB increased analgesic efficacy compared with CEI, and PCEA reduced local anesthetic consumption at the expense of inferior analgesia relative to CEI and PIEB. PIEB + PCEA was superior to CEI + PCEA in regard to the pain score at 2 h and 4 h, consumption of local anesthetic, incidence of lower lower limb motor blockade and the rate of spontaneous vaginal delivery. Fentanyl and remifentanil PCA did not provide the same level of analgesia as all epidural methods, resulted in increasing analgesic ineffectiveness with time spent in labour, and predisposed to a higher incidence of side effects such as nausea and/or vomiting and sedation. Remifentanil PCA was superior to fentanyl PCA for analgesia at an early time point, and it increased the incidence of oxygen desaturation relative to other strategies of delivering epidural solution.

CONCLUSIONS

Opioid PCA did not provide the same level of analgesia as epidural methods with a higher incidence of side effects. We interpret the findings of our systematic review and network meta-analysis as suggesting PIEB + PCEA to be the optimal delivery mode of epidural solution. Nevertheless, the potential differing importance of the various maternal, fetal, and neonatal outcomes in determining which is optimal has not, to our knowledge, been elucidated yet.

STUDY REGISTRATION

PROSPERO (CRD42021254978); registered 27 May 2021.

Peripheral Regional Anesthesia Using Local Anesthetics: Old Wine in New Bottles?

During the past decade, numerous efforts were undertaken aiming at prolonging the analgesic effect of regional anesthesia. With the development of extended-release formulations and enhanced selectivity for nociceptive sensory neurons, a very promising contribution to the development of pain medications has been achieved. At present, liposomal bupivacaine is the most popular, non-opioid, controlled drug delivery system, but its duration of action, which is still controversially discussed, and its expensiveness have decreased initial enthusiasm. Continuous techniques can be seen as an elegant alternative for providing a prolonged duration of analgesia, but for logistic or anatomical reasons, they are not always the best choice. Therefore, focus has been directed towards the perineural and/or intravenous addition of old and established substances. As for perineural application, most of these so-called 'adjuvants' are used outside their indication, and their pharmacological efficacy is often not or only poorly understood. This review aims to summarize the recent developments for prolonging the duration of regional anesthesia. It will also discuss the potential harmful interactions and side effects of frequently used analgesic mixtures.

Effect of adding dexmedetomidine on two methods of labor analgesia via epidural among parturient patients

Background

Continuous epidural infusion (CEI) has been an optimal and acceptable technique for inducing epidural anesthesia. This study compared two methods of programmed intermittent epidural bolus (PIEB) with CEI in labor analgesia among patients receiving epidural dexmedetomidine.

Methods

This study was a randomized clinical trial. The target population was term women candidates for epidural anesthesia. After selection of sample size based on inclusion criteria, a total of 3 cc of dexmedetomidine (0.5 µg/ml) and Ropivacaine 0.1% was injected. Furthermore, 5 ml was injected as a loading dose of dexmedetomidine 0.5 µg /ml and Ropivacaine 0.1%. Then the pain score was recorded. SPSS software Version 23 was used for statistical analysis of data.

Results

The neonatal Apgar score in PIEB method was more improved (P = 0.003) and the use of assisted delivery tools such as vacuum, in PIEB method was reduced. (p=0.038) Duration of the first phase of the labor in this method was more reduced than CEI.(p=0.015) Patients in the group undergoing epidural anesthesia by PIEB method were associated with a higher level of satisfaction with the delivery process (p < 0.05) than patients undergoing CEI protocol.

Conclusion

PIEB method is associated with further improvement in neonatal Apgar score and maternal outcomes (reduction in the duration of the first phase of labor and no need to use assisted delivery methods) compared to the CEI protocol, but has little effect on hemodynamic conditions or drug dosage.

Comparison of programmed intermittent epidural bolus injection and continuous epidural injection in controlling nighttime pain and improving sleep quality after thoracotomy

BACKGROUND

Postoperative pain after open thoracotomy is known to be very severe and affects sleep quality. This study aimed to investigate the effects of a programmed intermittent epidural bolus injection versus continuous epidural injection for controlling nighttime pain and improving sleep quality after thoracotomy.

METHODS

Seventy-six patients scheduled for open thoracotomy for lung cancer or other lung diseases were enrolled. The participants were divided into 2 groups. Group A was continuously injected with 0.2% levobupivacaine at 1.1 mL/h, and group B was injected intermittently with 3 mL 0.2% levobupivacaine at 3 hours intervals through a thoracic epidural catheter via a programmed infusion pump. Within 48 hours after surgery, the degree of pain control using visual analog scale and the patients' sleep conditions on postoperative day (POD) 0 and 1 were evaluated, and other adverse events were investigated.

RESULTS

On POD 1 night, the visual analog scale in group B showed lower than group A (P = .009). Comparison of time to fall asleep showed no differences between 2 groups. Total sleep time was no difference on POD 0 but was longer in group B than that in group A on POD 1 (P = .042). Awakening from sleep on POD 0 was lower in group B than that in group A (P = .033), and satisfaction with sleep quality on POD 0 was superior in group B compared to group A (P = .005). Postoperative nausea and vomiting occurred more frequently in group B than in group A (P = .018).

CONCLUSION

The programmed intermittent epidural bolus technique of patient-controlled epidural analgesia reduces postoperative nighttime pain and improves sleep quality in patients undergoing thoracotomy for lung cancer or other lung diseases.

Optimization of programmed intermittent epidural bolus volume for different concentrations of ropivacaine in labor analgesia: a biased coin up-and-down sequential allocation trial

Background and objectives

To date, programmed intermittent epidural bolus (PIEB) has been widely used in obstetric analgesia, while no optimal PIEB regimen has been proposed. This study aimed to assess effective analgesia in 90% of women (EV90) with different concentrations of ropivacaine (0.075% and 0.1%) combined with 0.5 µg/mL sufentanil, at an interval of 40 min using the biased coin design-up-and-down method (BCD-UDM), and to explore whether there is a difference in EV90 with the increase of ropivacaine concentration.

Methods

In total, 103 primiparous women were assigned to two groups, including group A (n = 52) and group B (n = 51). Parturients in group A were treated with 0.075% ropivacaine and 0.5 µg/mL sufentanil, while those in group B were treated with 0.1% ropivacaine and 0.5 µg/mL sufentanil. Used the biased coin up-and-down sequential allocation method to determine the EV90. The secondary outcomes were sensory block level, motor block, and adverse events (hypotension, urinary retention, and pruritus).

Results

The results revealed that EV90 was 10 mL (95% confidence interval (CI):8.03–11.54) in group A, and EV90 was 9 mL (95% CI:7.49–10.51) in group B by the isotonic regression method. The highest level of the sensory block was T8, and the lowest was T12. No case of hypotension was recorded,and only 4 parturients complained of motor block.

Conclusion

With an interval of 40 min, the optimal PIEB bolus volume of 0.075% ropivacaine and 0.5 µg/mL sufentanil was 10 mL, 0.1% ropivacaine and 0.5 µg/mL sufentanil was 9 mL. Moreover, the PIEB volume decreased along with the higher concentration of ropivacaine.

Trial registration

ChiCTR registration number: ChiCTR2000040917. Registration date: December 15, 2020.

A survey of labour epidural practices at obstetric anesthesia fellowship programs in the United States

Purpose

Labour epidural analgesia (LEA) is an evolving field. Various neuraxial techniques and dosing regimens are available to the modern obstetric anesthesia provider, allowing for significant practice variability. To begin a search for consensus on optimal care, we sought to query fellowship training practices for LEA.

Methods

We conducted an electronic survey of institutions with American Council for Graduate Medical Education-accredited obstetric anesthesiology fellowship programs. We studied the frequency of epidural initiation techniques, including combined spinal epidural (CSE), dural puncture epidural, and epidural bolus. For maintenance techniques, we appraised the use of continuous epidural infusion, programmed intermittent bolus (PIEB), and patient-controlled epidural analgesia (PCEA).

Results

Of 40 institutions surveyed, we received 32 responses (80% response rate). Twenty-eight of 40 (70%) were included in the analysis. A plurality of institutions (12/28; 43%) preferred CSE, and among those who used CSE, 23/27 (85%) included intrathecal opioids. A majority of institutions used protocols with PIEB (55%), while almost all (92%) used PCEA. Most participants (88%) reported using dilute concentration maintenance infusions of 0.1% bupivacaine/ropivacaine or less.

Conclusion

Despite significant variability in LEA practice, some clear patterns emerged in our survey, including preference for opioid-containing CSE and maintenance with PIEB, PCEA, and dilute epidural solutions.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12630-022-02192-6.

Programmed Intermittent Epidural Bolus in Comparison with Continuous Epidural Infusion for Uterine Contraction Pain Relief After Cesarean Section: A Randomized, Double-Blind Clinical Trial

Purpose

Programmed intermittent epidural bolus (PIEB) was reported to provide superior maintenance of labour analgesia with better pain relief and less motor block than continuous epidural infusion (CEI). Whether this is also evident for uterine contraction pain relief after cesarean section remains unknown.

Patients and Methods

Parturients scheduled for cesarean section were recruited for the study. At the end of the surgery, after a similar epidural loading dose given, patients received either PIEB (6 mL·h⁻¹) or CEI (6 mL·h⁻¹) of 0.1% ropivacaine. The primary outcome was the uterine contraction pain assessed with visual analog scale (VAS-U) at the postoperative 36 h. Secondary outcomes included incision pain at the rest (VAS-R) and in the movement-evoked (VAS-P), and lower extremity motor block (defined as Bromage score > 0). The whole profile of VAS scores between groups was analyzed using linear mixed model. When significant differences were found, the pairwise comparison was done with the Mann Whitney U-test followed by Bonferroni correction.

Results

One hundred and twenty parturients were studied (PIEB, 60; CEI, 60). VAS-U at the postoperative 36 h in the PIEB group was lower than in the CEI group (Bonferroni-adjusted P < 0.01). The linear mixed model indicated that VAS-U, VAS-R and VAS-P were lower in the PIEB group compared with the CEI group (all P < 0.01). Motor block was higher in the CEI group than in the PIEB group during the study period except 2 h (all P < 0.05). No differences of adverse events such as hypotension and urinary retention were observed between the two groups.

Conclusion

Programmed intermittent epidural bolus provides more effective uterine contraction and incision pain relief and less motor block after cesarean section than continuous epidural infusion without an increased risk of urinary retention and blood pressure instability.

Programmed intermittent epidural bolus in parturients: A meta-analysis of randomized controlled trials

BACKGROUND

To evaluate the efficacy and safety of programmed intermittent epidural bolus (PIEB) in parturients.

METHODS

The PubMed, Embase, and the Cochrane Library (from inception to July 2021) were searched for identification of randomized placebo-controlled trials in which PIEB was applied in parturients. The outcomes were the effect of analgesia, satisfaction score, mode of delivery, duration of labor, neonatal condition, and adverse events. The pooled odds ratios (OR), weighted mean difference (WMD), and 95% confidence intervals (CIs) were calculated using random- and fixed-effects models.

RESULTS

PIEB was found to be associated with decreased total consumption of ropivacaine (WMD = -15.83, 95% CI: -19.06 to -12.60, P < .00001; I2 = 61%; P for heterogeneity = .04), total consumption of sufentanil (WMD = -4.93, 95% CI: -6.87 to 2.98, P < .00001; I2 = 68%; P for heterogeneity = .05), numbers of patients who require patient-controlled epidural analgesia bolus (OR = 0.27, 95% CI: 0.14-0.51, P < .0001; I2 = 65%; P for heterogeneity = .01), the number of attempts (WMD = -4.12, 95% CI: -7.21 to -1.04, P = .009; I2 = 100%; P for heterogeneity < .00001), rate of breakthrough pain (OR = 0.47, 95% CI: 0.28-0.80, P = .005; I2 = 47%; P for heterogeneity = .09). Eight studies focus on the duration of analgesia. After by meta-analysis, we found that the pain visual analogue scale (VAS) score at 30 minutes, 2 hours, 4 hours, and 5 hours in PIEB group was significantly lower when compared with control group, (WMD = -0.15, 95% CI: -0.26 to -0.04, P = .006; I2 = 0%; P for heterogeneity = .64), (WMD = -0.79, 95% CI: -1.32 to 0.25, P = .004; I2 = 97%; P for heterogeneity < .00001), (WMD = -1.00, 95% CI: -1.08 to -0.91, P < .00001; I2 = 0%; P for heterogeneity = .67), (WMD = -1.81, 95% CI: -3.23 to -0.39, P = .01; I2 = 98%; P for heterogeneity < .00001), respectively. Nineteen studies discussed the mode of delivery between 2 groups. The results suggest that the rate of normal delivery is significantly higher in PIEB group compared with control group (OR = 1.37, 95% CI: 1.08-1.75, P = .01). The time of first and second stage of labor are significantly shorter in PIEB group compared with control group, the result is (WMD = -10.52, 95% CI: -14.74 to 4.76, P < .00001; I2 = 0%; P for heterogeneity = .86), (WMD = -1.48, 95% CI: -2.26 to -0.69, P = .0002; I2 = 35%; P for heterogeneity = .10), respectively. Thirteen studies concerned the satisfaction score of patients. The satisfaction score of patients in the PIEB group was significantly higher when compared with control group (WMD = 0.91, 95% CI: 0.42-1.39, P = .0003; I2 = 98%; P for heterogeneity < .00001). The Apgar score at 1, 5 minutes in PIEB group are significantly higher (WMD = 0.07, 95% CI: 0.02-0.13 P = .007; I2 = 55%; P for heterogeneity = .04), (WMD = -0.08, 95% CI: -0.12 to -0.05, P < .00001; I2 = 21%; P for heterogeneity = .27), respectively.

CONCLUSIONS

PIEB is a good alternative for labor analgesia with better analgesic effect, maternal and infant outcome.

Programmed intermittent epidural bolus for labour analgesia: a randomized controlled trial comparing bolus delivery speeds of 125 mL·hr-1 versus 250 mL·hr-1

PURPOSE

Programmed intermittent epidural bolus (PIEB) provides better analgesia for labour pain than continuous epidural infusion does. Nevertheless, commonly used PIEB regimens are associated with high sensory block. We hypothesized that a PIEB technique with slower bolus delivery speed would produce lower sensory levels.

METHODS

We recruited term nulliparous women with singleton pregnancies during the first stage of labour. All participants had an American Society of Anesthesiologists Physical Status score of II-III, had epidural catheters placed at L3/4, and had epidural analgesia maintained with PIEB 10 mL every 40 min using 0.0625% bupivacaine with fentanyl 2 µg·mL^-1. Women were randomized to receive PIEB delivered at 250 mL·hr^-1 (G250) or 125 mL·hr^-1 (G125). The study was completed six hours after the loading dose or at full cervical dilatation, whichever occurred first. The primary outcome was the presence of sensory block to ice ≥ T6 in at least one assessment during the study period (maximum six hours).

RESULTS

We analyzed data from 90 women. The proportion of women presenting sensory block ≥ T6 at any time was not different between G125 and G250 groups (60.0% vs 64.4%; difference, -4.4%; 95% confidence interval [CI], -24.5 to 15.6; P = 0.66). The median [interquartile range] highest sensory block level was also not different between G125 and G250 groups (T6 [T7-T5] vs T5 [T7-T5], P = 0.39). Women in the G125 group had a lower incidence of hypotension than women in the G250 group did (11.1% vs 33.3%; difference, -22.2%; 95% CI, -38.8 to -5.67; P = 0.01). Quality of analgesia and patient satisfaction were not different between groups.

CONCLUSION

The maintenance of epidural analgesia with a PIEB delivery speed of 125 mL·hr^-1 did not produce lower sensory block levels when compared with 250 mL·hr^-1. The slower injection speed regimen was associated with lower incidence of hypotension, but this secondary finding warrants confirmation in a future trial.

TRIAL REGISTRATION

www.ClinicalTrials.gov (NCT03236298); registered 1 August 2017.

Programmed intermittent epidural bolus for post-cesarean delivery analgesia: a randomized controlled double-blind trial

PURPOSE

The aim of this study was to assess the efficacy of programmed intermittent epidural boluses (PIEB) in postoperative pain management compared with continuous epidural infusion (CEI) after cesarean delivery.

METHODS

A total of 58 participants were randomly allocated to receive PIEB (3 mL bolus every 60 min) or CEI (3 mL/h) for postoperative analgesia after undergoing elective cesarean section under combined spinal-epidural anesthesia. Both groups had the same epidural solution containing ropivacaine 0.2% plus fentanyl 2 µg/mL. The primary outcome was postoperative pain score at rest and mobilization at 6, 12, 24, and 48 h. The secondary outcomes were the total amount of ropivacaine used in the 48 h study period and the time to the first PCEA bolus.

RESULTS

Data from 58 women were analyzed. There was a reduction in pain verbal numerical rating scores at 12 h in patients receiving PIEB compared with CEI at rest [2 (1.75-3) vs. 3 (2-4), p = 0.011]; and on movement [4 (3-5) vs. 5 (4-6), p = 0.038]. No differences were found in pain scores at any other time-point up to 48 h. Total ropivacaine consumption at 48 h was less in the PIEB group compared with the CEI group [316 mg (304-321) vs. 336 mg (319-344), p = 0.001].

CONCLUSION

Postoperative epidural analgesia for patients who underwent cesarean delivery with PIEB compared with CEI resulted in less ropivacaine usage while providing comparable analgesia.

Effect of patient-controlled epidural analgesia with and without automatic intermittent bolus on levobupivacaine consumption during labour: A single-centre prospective double-blinded randomised controlled study

BACKGROUND

During labour, the effects of adding a programmed intermittent epidural bolus (PIEB) baseline analgesic regimen to patient-controlled epidural analgesia (PCEA) remain uncertain.

METHODS

This single centre prospective double-blinded controlled study randomised nulliparous women over 35 weeks of gestational age in a PCEA + PIEB or PCEA only group. After an epidural analgesia catheter was inserted, a specific pump administered a solution of levobupivacaine 0.625 mg mL^-1, sufentanil 0.25 µg mL^-1, and clonidine 0.375 µg mL^-1. In both groups the PCEA mode delivered an 8 mL bolus with a lockout period of 8 min. In the PCEA + PIEB group, women also received a programmed 8 mL bolus every 60 min. Additional bolus were allowed if required. The primary outcome was the hourly consumption of levobupivacaine from epidural catheter placement to new-born delivery. Secondary outcome were motor block, oxytocin use, sufentanil consumption, additional bolus required, instrumental vaginal delivery, unplanned caesarean section, pain during labour and women's satisfaction.

RESULTS

Analysis included 162 and 155 women in the PCEA and PCEA + PIEB groups, respectively. The median [IQR] hourly consumption of levobupivacaine was significantly lower in the PCEA group (9.9 (7.8-12.4] mg h^-1) as compared to the PCEA + PIEB group (11.2 [7.9-14.3] mg h^-1; p = 0.046). The difference between medians was 1.3 mg h^-1 95 % CI (0.1-2.9). There was no difference between groups for secondary outcomes.

CONCLUSIONS

PCEA only modestly decreased the hourly consumption of local anaesthetic as compared to PCEA + PIEB but the difference was not clinically relevant.

Programmed intermittent epidural bolus for labour analgesia during first stage of labour: a sequential allocation trial to determine the effective interval time between boluses of a fixed volume of 2.5 mL of bupivacaine 0.25% plus fentanyl 8 µg·mL-1

PURPOSE

We studied the programmed intermittent epidural bolus (PIEB) time interval between boluses of 2.5 mL of bupivacaine 0.25% with fentanyl 8 µg·mL^-1 to produce effective analgesia in 90% of women (EI90) during the first stage of labour.

METHODS

In a double-blind sequential allocation trial using a biased coin up-and-down design to determine the EI90, the PIEB boluses of 2.5 mL of 0.25% bupivacaine plus fentanyl 8 µg·mL^-1 were delivered at varying intervals-60, 50, 40, and 30 min. The primary outcome was the adequate response of the patient to the PIEB regimen, defined as no use of supplemental analgesia for six hours or until the first stage of labour was completed, whichever came first. The secondary outcomes were the upper sensory block level to ice, motor block and hypotension. The isotonic regression with extrapolation approach was used to estimate the EI90.

RESULTS

In the 20 women studied, the estimated EI90 was 20 (95% CI, 5.9 to 28.8) min. For the secondary outcomes, we classified women into those assigned to 30 min (16 women) and those assigned to more than 30 min (four women). The median upper sensory block for women in the 30-min group and more than 30 min were T6 (or T5) and T7, respectively. No participants experienced motor block. Hypotension occurred in one patient in the 30-min group.

CONCLUSION

The estimated EI90 for boluses of 2.5 mL of bupivacaine 0.25% with fentanyl 8 µg·mL^-1 was 20 (95% CI, 5.9 to 28.8) min. These results suggest that there is no advantage in using this regimen compared with those reported in the literature using the same dose of bupivacaine in concentrations of 0.0625% and 0.125%.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT03735771); registered 7 November 2018.

COVID in obstetrics: labor analgesia and cesarean section

PURPOSE OF REVIEW

This review is based on the latest evidence to provide a good standard of care for COVID-19 parturients and protection to healthcare givers.

RECENT FINDINGS

COVID-19 by itself is not an indication for cesarean section. Different publications demonstrated the efficacy of neuraxial analgesia/anesthesia for delivery. Although SARS-CoV-2 was associated with a certain neurotropism, neuraxial block was not associated with neurological damage in COVID-19 parturients, and seems as safe and effective as in normal situations. It permits to avoid a general anesthesia in case of intrapartum cesarean section. Epidural failure is a concern: it may lead to a general anesthesia in case of emergency cesarean section. Local protocols and well-trained anesthesiologists will be helpful. COVID-19 patients require special circuits and every step (transfer to and from theatre, recovery, analgesia, and so on) should be planned in advance. For cesarean section under general anesthesia, personal protection equipment must be enhanced. Postoperative analgesia with neuraxial opioids, NSAIDs, or regional blocks are recommended. COVID-19 and pregnancy increase the risk of thrombosis, so thromboprophylaxis has to be considered and protocolized.

SUMMARY

Anesthetic care for delivery in COVID-19 parturients should include neuraxial blocks. Special attention should be paid on the risk of thrombosis.

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.

Postoperative Pain Management in Pediatric Spinal Fusion Surgery for Idiopathic Scoliosis

This article reviews and summarizes current evidence and knowledge gaps regarding postoperative analgesia after pediatric posterior spine fusion for adolescent idiopathic scoliosis, a common procedure that results in severe acute postoperative pain. Inadequate analgesia may delay recovery, cause patient dissatisfaction, and increase chronic pain risk. Despite significant adverse effects, opioids are the analgesic mainstay after scoliosis surgery. However, growing emphasis on opioid minimization and enhanced recovery has increased adoption of multimodal analgesia (MMA) regimens. While opioid adverse effects remain a concern, MMA protocols must also consider risks and benefits of adjunct medications. We discuss use of opioids via different administration routes and elaborate on the effect of MMA components on opioid/pain and recovery outcomes including upcoming regional analgesia. We also discuss risk for prolonged opioid use after surgery and chronic post-surgical pain risk in this population. Evidence supports use of neuraxial opioids at safe doses, low-dose ketorolac, and methadone for postoperative analgesia. There may be a role for low-dose ketamine in those who are opioid-tolerant or have chronic pain, but the evidence for preoperative gabapentinoids and intravenous lidocaine is currently insufficient. There is a need for further studies to evaluate pediatric-specific optimal MMA dosing regimens after scoliosis surgery. Questions remain regarding how best to prevent acute opioid tolerance, opioid-induced hyperalgesia, and chronic postsurgical pain. We anticipate that this timely update will enable clinicians to develop efficient pain regimens and provide impetus for future research to optimize recovery outcomes after spine fusion.

Hydromorphone population pharmacokinetics in pediatric surgical patients

BACKGROUND

Hydromorphone is an opioid agonist used for pediatric analgesia. Due to lack of data, pediatric dosing (based on adult pharmacokinetic models) is not optimal.

AIM

This study characterizes hydromorphone population pharmacokinetics in pediatric surgical patients.

METHODS

In this prospective observational study, 34 children (4-18 years, bodyweight 23-89.6 kg) received multiple intravenous hydromorphone boluses followed by postoperative hydromorphone patient-controlled analgesia. Arterial blood samples were collected before and at 3, 10, 30, and 90 (and few samples at 1350) minutes after the first dose. Hydromorphone concentrations were measured by validated LC-MS/MS assay. Nonlinear mixed-effects modeling was used for pharmacokinetic model development. The final population pharmacokinetic model was evaluated by visual predictive check and bootstrap analysis. Monte Carlo simulations based on the final pharmacokinetic model determined optimal patient-controlled analgesia parameters to achieve a target of 20 ng/mL (as the median effective analgesic concentration), using minimum effective analgesic concentration of 4 ng/mL as a proxy for patient-controlled analgesia dose demand, and not exceeding the defined safe upper threshold of 40 ng/mL.

RESULTS

Hydromorphone pharmacokinetic profiles were adequately described by a two-compartmental model with first-order elimination. Bodyweight was found to be a significant covariate for hydromorphone clearance. Allometrically scaledpharmacokinetic parameter estimates (per 70 kg), systemic clearance (0.748 L/min), volume of distribution (33 L), peripheral clearance (1.57 L/min), and peripheral volume of distribution (146 L) were similar to reported adult parameter estimates. Sex, race, age, and type of surgery were not identified as significant covariates. To identify optimal patient-controlled analgesia dosing parameters, we simulated several initial loading doses, demand doses, and lockout intervals. Our simulations support an initial patient-controlled analgesia loading dose of 15 µg/kg followed by a demand dose of 6 µg/kg with lockout intervals of 20 minutes.

CONCLUSIONS

After intravenous hydromorphone, plasma pharmacokinetic profiles in children undergoing different surgeries were well described by a two-compartment population allometric pharmacokinetic model using bodyweight as the size descriptor. Model informed simulations identified patient-controlled analgesia parameters to inform initial settings, with adjustments as needed based on observed individual effects.

A Meta-Analysis of Comparing Intermittent Epidural Boluses and Continuous Epidural Infusion for Labor Analgesia

With the development of medical equipment and techniques in labor anesthesia, it is a major issue to investigate the risks and treatment effects among techniques such as continuous epidural infusion (CEI) and intermittent epidural bolus (IEB). However, there is a controversial result regarding two techniques. This study was conducted through meta-analysis of randomized controlled trials (RCTs) for labor analgesia between the CEI and IEB techniques. The pooled results were presented as weighted mean differences (WMDs) together with 95% confidence intervals (CIs) and odds ratios (ORs) together with 95% CIs, respectively. Eleven RCTs were included in this meta-analysis. Four hundred sixty-five parturients accepted CEI, whereas 473 parturients accepted IEB labor analgesia. Elven identified low- risk bias studies were recruited for meta-analysis. The results presented no statistical difference in cesarean delivery rate between IEB and CEI (OR, 0.96; 95% CI, 0.67-1.37) and duration of second stage of labor (WMD, -3.82 min; 95% CI, -8.28 to 0.64). IEB had statistically significant lessened risk of instrumental delivery (OR, 0.59; 95% CI, 0.39-0.90) and for the use in local anesthetic (WMD, -1.71 mg bupivacaine equivalents per hour; 95% CI, -1.88 and -1.55). Accepted IEB had a higher score of maternal satisfaction (WMD, -6.95 mm; 95% CI, -7.77 to -6.13). Based on evidence, IEB showed a greater benefit for slightly reducing the use in local anesthetic, reduced risk of instrumental delivery, and improved maternal satisfaction for the requirement of labor epidural analgesia for healthy women. In the future, more studies need to be conducted to practice the IEB regimen and explore its influence on labor analgesia.

Comparative analgesic efficacy and safety of intermittent local anaesthetic epidural bolus for labour: a systematic review and meta-analysis

BACKGROUND

Continuous epidural infusion (CEI) is commonly used for labour analgesia, but concerns over potential motor block, second-stage labour complications, and ineffective analgesia in late labour have prompted examining intermittent epidural bolus (IEB) as an alternative. However, evidence comparing these modalities is conflicting. The meta-analysis evaluates the analgesic efficacy of CEI vs IEB.

METHODS

Databases were searched for trials comparing CEI to IEB for labour analgesia. The two co-primary outcomes were risk of breakthrough pain and difference in area under the curve (AUC) for pain scores during the first 4 h post-epidural initiation. Local anaesthetic consumption, maternal outcomes (i.e. delivery mode, labour duration, and maternal satisfaction), and side-effects of epidural analgesia were also evaluated. Results were pooled using random-effects modelling. Trial sequential analysis (TSA) was used to evaluate evidence reliability.

RESULTS

Twenty-seven studies (3133 patients) were analysed. Compared with CEI, IEB decreased risk of breakthrough pain by 38% (risk ratio [95% confidence interval {CI}] of 0.62 [0.48, 0.81]; P=0.0004; I²=47%; 1164 patients) and reduced AUC of pain during the 4 h interval by 32.9% (mean difference [95% CI] of -16.7 mm h^-1 [-18.9, -14.4]; P<0.0001; 1638 patients). Intermittent epidural bolus enhanced maternal satisfaction, shortened labour duration, decreased motor block, and reduced local anaesthetic consumption. The difference between the two groups was not statistically significant for epidural side-effects or mode of delivery. The TSA indicated adequate power for reliable inferences.

CONCLUSIONS

Intermittent epidural bolus provides improved labour pain control during the first 4 h after epidural initiation with less breakthrough pain. Moderate- to high-quality evidence of intermittent epidural bolus superiority support its use as a safe and effective continuous epidural infusion alternative for labour analgesia.

Programmed intermittent epidural bolus vs. patient-controlled epidural analgesia for maintenance of labour analgesia: a two-centre, double-blind, randomised study†

The programmed intermittent epidural bolus technique has shown superiority to continuous epidural infusion techniques, with or without patient-controlled epidural analgesia for pain relief, reduced motor block and patient satisfaction. Many institutions still use patient-controlled epidural analgesia without a background infusion, and a comparative study between programmed intermittent epidural bolus and patient-controlled epidural analgesia without a background infusion has not yet been performed. We performed a randomised, two-centre, double-blind, controlled trial of these two techniques. The primary outcome was the incidence of breakthrough pain requiring a top-up dose by an anaesthetist. Secondary outcomes included: motor block; pain scores; patient satisfaction; local anaesthetic consumption; and obstetric and neonatal outcomes. We recruited 130 nulliparous women who received initial spinal analgesia, and then epidural analgesia was initiated and maintained with either programmed intermittent epidural bolus or patient-controlled epidural analgesia using ropivacaine 0.12% with sufentanil 0.75 µg·ml^-1 . The programmed intermittent epidural bolus group had a programmed bolus of 10 ml every hour, with on-demand patient-controlled epidural analgesia boluses of 5 ml with a 20 min lockout, and the patient-controlled epidural analgesia group had a 5 ml bolus with a 12 min lockout interval; the potential maximum volume per hour was the same in both groups. The patients in the programmed intermittent epidural bolus group had less frequent breakthrough pain compared with the patient-controlled epidural analgesia group, 7 (10.9%) vs. 38 (62.3%; p < 0.0001), respectively. There was a significant difference in motor block (modified Bromage score ≤ 4) frequency between groups, programmed intermittent epidural bolus group 1 (1.6%) vs. patient-controlled epidural analgesia group 8 (13.1%); p = 0.015. The programmed intermittent epidural bolus group had greater local anaesthetic consumption with fewer patient-controlled epidural analgesia boluses. Patient satisfaction scores and obstetric or neonatal outcomes were not different between groups. In conclusion, we found that a programmed intermittent epidural bolus technique using 10 ml programmed boluses and 5 ml patient-controlled epidural analgesia boluses was superior to a patient-controlled epidural analgesia technique using 5 ml boluses and no background infusion.

Intermittent epidural bolus versus continuous epidural infusions for labor analgesia: A meta-analysis of randomized controlled trials

There are inconsistent results regarding the efficacy and safety of intermittent epidural bolus (IPB) versus continuous epidural infusions (CPI) for labor analgesia. This study used a meta-analytic approach to assess the safety and treatment efficacy of IPB versus CPI for labor analgesia based on randomized controlled trials (RCTs). Four electronic databases were used to identify eligible RCTs. Pooled effect estimates at 95% confidence intervals (CIs) were calculated using a random-effects model. Twenty-two RCTs with 2,573 parturients were selected for final analysis. The findings revealed no significant differences between IPB and CPI for the incidences of cesarean and instrumental delivery. IPB was shown to be associated with shorter total duration of labor [weighted mean difference (WMD): −21.46; 95% CI: −25.07 to −17.85; P < 0.001], duration of the first of stage of labor (WMD: −13.41; 95% CI: −21.01 to −5.81; P = 0.001), and duration of the second stage of labor (WMD: −4.98; 95% CI: −9.32 to −0.63; P = 0.025). Furthermore, IPB significantly reduced the incidences of required anesthetic interventions compared with CPI [relative risk (RR): 0.61; 95% CI: 0.39–0.95; P = 0.030], whereas there was no significant difference between IPB and CPI for the time required in the first anesthetic intervention (WMD: 7.73; 95% CI: −33.68–49.15; P = 0.714). The local anesthetic IPB (bupivacaine equivalents) was associated with lower milligrams per hour of local anesthetic (WMD: −0.89; 95% CI: −1.41 to −0.36; P = 0.001) and better maternal satisfaction (WMD: 8.76; 95% CI: 4.18–13.35; P < 0.001). There were no significant differences between IPB and CPI for the risk of adverse events. This study found that parturients with IPB have short total duration of labor and duration of the first and second stage of labor, reduced requirements for additional anesthetic interventions, and improved maternal satisfaction.

Epidural use in labour is not associated with an increased risk of maternal or neonatal morbidity when the second stage is prolonged

BACKGROUND

Epidural analgesia increases length of labour and risk of operative delivery (caesarean or instrumental).

AIM

This study aimed to assess the impact of epidural anaesthesia on maternal and neonatal adverse outcomes when the second stage of labour was prolonged.

METHODS

A retrospective cohort study of women delivering at term at the Mater Mother's Hospital, Brisbane between 2008 and 2017. Intrapartum, maternal and neonatal outcomes were assessed and dichotomised according to the presence of prolonged second stage of labour and further by epidural use. Prolonged second stage of labour was defined as: nulliparous women ≥3 h (with epidural) and ≥2 h (without); multiparous women ≥2 h (with epidural) and ≥1 h (without).

RESULTS

There were 48 352 women who met the inclusion criteria - 43 676 without and 4676 with prolonged second stage of labour. The overall epidural rate was 35.9%. Women with epidural had significantly lower odds of achieving a spontaneous vaginal birth and higher odds of an operative birth regardless of length of second stage. While rates of several adverse maternal and neonatal outcomes were higher when the second stage was prolonged, after adjusting for clinically relevant confounders, epidural use was not associated with increased odds of the majority of these adverse outcomes. Indeed, epidural use was associated with a significant reduction in the odds of obstetric anal sphincter injuries and reduced odds of neonatal acidosis in women with prolonged second stage.

CONCLUSION

While epidural increases the risk of operative birth, this is not associated with an increase in adverse maternal or neonatal outcomes.

Programmed intermittent epidural bolus as compared to continuous epidural infusion for the maintenance of labor analgesia: a prospective randomized single-blinded controlled trial

Background

Programmed intermittent epidural bolus (PIEB) techniques are a new area of interest for maintaining labor analgesia due to the potential to decrease motor block and improve labor analgesia. This study compares continuous epidural infusion (CEI) to 2 PIEB regimens for labor analgesia.

Methods

One hundred fifty patients undergoing scheduled induction of labor at term gestation having epidural labor analgesia were randomized to receive an epidural analgesia regimen of bupivacaine 0.125% with fentanyl 2 μg/ml at either PIEB 5 ml every 30 min (Group 5q30), PIEB 10 ml every 60 min (Group 10q60), or 10 ml/h continuous infusion (Group continuous epidural infusion [CEI]). The primary outcome is the pain scores throughout labor. Secondary outcomes include degree of motor block, dermatomal sensory levels, the number of physician-administered boluses, and patient satisfaction.

Results

While the average pain scores throughout labor did not differ significantly between groups, fewer patients in group 10q60 received physician-administered boluses for breakthrough pain (34.9% in 10q60 vs. 61.0% in 5q30 and 61.9% in CEI, P = 0.022). Dermatomal sensory levels, degree of motor block, and patient satisfaction did not differ significantly between groups.

Conclusions

Our study suggests that high volume PIEB regimens for labor analgesia decrease breakthrough pain and physician-administered boluses.