Programmed Intermittent Epidural Bolus Research Articles

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

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. 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. Bayesian network meta-analysis. PubMed, Embase, CENTRAL, Web of Science and Wanfang Data were searched from January 1988 to August 2023 without language restriction. 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. 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. 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. PROSPERO (CRD42023402540).

Optimum programmed intermittent epidural bolus interval time of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL: a randomized controlled trial.

The aim of our study was to administer adequate local anesthetic in programmed intermittent epidural bolus (PIEB) to avoid breakthrough pain and decrease the use of manual and PCEA boluses. We, therefore, conducted this study to determine the effective PIEB interval time between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL in 90% of subjects (EI90), without the use of patient-controlled epidural analgesia (PCEA). A total of 80 subjects were included in the final statistical analysis from 23 August 2022 to 22 November 2022. The subjects were randomly assigned to one of four different PIEB time intervals: 40, 50, 60, and 70min (groups 40, 50, 60, and 70), respectively. The primary outcome was the effective epidural labor analgesia, defined as no use of PCEA bolus or a manual bolus until the end of the first stage of labor or within 6hours after loading dose administration. The PIEB EI90 (95% CI) between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL was estimated using probit regression. The effective PIEB interval time between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL in 90% of subjects without the use of PCEA was 45.4 (35.5-50.5) minutes using probit regression. No statistical differences were found in the proportion of subjects with Bromage score > 0, hypotension, pruritus, nausea, and vomiting between groups. However, the highest sensory block (pinprick) in the 40-min group was significantly higher than that in the other groups. The estimated value for EI90 for PIEB between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4μg/ml at a fixed volume of 10mL using probit regression was 45.4 (35.5-50.5) minutes. Furthermore, future studies are warranted to be established to determine the optimal parameters for different regimens in clinical practice.

Comparison of analgesic effects between programmed intermittent epidural boluses and continuous epidural infusion after cesarean section: a randomized controlled study.

This study aimed to compare the analgesic effects of programmed intermittent epidural boluses (PIEB) and continuous epidural infusion (CEI) for postoperative analgesia after elective cesarean section (CS). Seventy-four women who underwent elective CS were randomized to receive either PIEB or CEI. The PIEB group received 4 ml-intermittent boluses of 0.11% ropivacaine every hour at a rate of 120 ml/h. The CEI group received a constant rate of 4 ml/h of 0.11% ropivacaine. The primary outcome was the pain score at rest at 36 h after CS. Secondary outcomes included the pain scores during mobilization, time-weighted pain scores, the incidence of motor blockade, and complications-related epidural analgesia during 36 h after CS. The pain score at rest at 36 h after CS was significantly lower in the PIEB group compared with that in the CEI group (3.0 vs. 0.0; median difference, 2; 95% CI: 1, 2; P < 0.001). The mean time-weighted pain scores at rest and during mobilizations were also significantly lower in the PIEB group than in the CEI group (pain at rest: mean differences, 37.5; 95% CI, [24.6, 50.4]; P < 0.001; pain during mobilization: mean difference, 56.6; 95% CI, [39.8, 73.5]; P < 0.001). The incidence of motor blockade was significantly reduced in the PIEB group compared with that in the CEI group (P < 0.001). PIEB provides superior analgesia with less motor blockade than CEI in postpartum women after CS, without any apparent adverse events.

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).

Comparison of Labor Analgesia Efficacy Between Single-orifice and Multiorifice Wire-reinforced Catheters During Programmed Intermittent Epidural Boluses: A Randomized Controlled Clinical Trial

(Reg Anesth Pain Med. 2023;48:61–66) Programmed intermittent epidural bolus (PIEB) has been used since 2006 for labor analgesia. It is theorized that high-flow epidural catheters may be necessary for proper anesthetic spread dynamics within the epidural space. Epidural catheters have varying characteristics that may affect anesthesia administration. Studies show that multiorifice catheters were proven superior when compared with single-orifice catheters; however, due to flow dynamics, single-orifice catheters may be preferred to close-ended multiorifice catheters due to diffusion distance and area coverage. This study aimed to show a comparison between single-orifice and multiorifice catheters when used for intermittent high-rate bolus administration.

Randomized Assessment of the Optimal Time Interval Between Programmed Intermittent Epidural Boluses When Combined With the Dural Puncture Epidural Technique for Labor Analgesia

(Anesth Analg. 2023;136:532–539) Neuraxial labor analgesia has advanced to include the dural puncture epidural (DPE) and the programmed intermittent epidural bolus (PIEB) techniques. This study aimed to test the appropriate interval for effective analgesia when the DPE technique is followed by the PIEB technique. This study used fixed volumes of PIEB at 10 mL of ropivacaine 0.1% and 0.5 mg/mL of sufentanil.

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.

Assessing Continuous Epidural Infusion and Programmed Intermittent Epidural Bolus for Their Effectiveness in Providing Labor Analgesia: A Mono-Centric Retrospective Comparative Study.

Background and Objectives: Local anesthetics administered via epidural catheters have evolved from intermittent top-ups to simultaneous administration of continuous epidural infusion (CEI) and patient-controlled epidural analgesia (PCEA) using the same device. The latest programmed intermittent epidural bolus (PIEB) model is believed to create a wider and more even distribution of analgesia inside the epidural space. The switch from CEI + PCEA to PIEB + PCEA in our department began in 2018; however, we received conflicting feedback regarding workload from the quality assurance team. This study aimed to investigate the benefits and drawbacks of this conversion, including the differences in acute pain service (APS) staff workload, maternal satisfaction, side effects, and complications before and after the changeover. Materials and Methods: Items from the APS records included total delivery time, average local anesthetic dosage, and the formerly mentioned items. The incidence of side effects, the association between the duration of delivery and total dosage, and hourly medication usage in the time subgroups of the CEI and PIEB groups were compared. The staff workload incurred from rescue bolus injection, catheter adjustment, and dosage adjustment was also analyzed. Results: The final analysis included 214 and 272 cases of CEI + PCEA and PIEB + PCEA for labor analgesia, respectively. The total amount of medication and average hourly dosage were significantly lower in the PIEB + PCEA group. The incidences of dosage change, manual bolus, extra visits per patient, and lidocaine use for rescue bolus were greater in the PIEB + PCEA group, indicating an increased staff workload. However, the two groups did not differ in CS rates, labor time, maternal satisfaction, and side effects. Conclusions: This study revealed that while PIEB + PCEA maintained the advantage of decreasing total drug doses, it inadvertently increased the staff burden. Increased workload might be a consideration in clinical settings when choosing between different methods of PCEA.

Effect of programmed intermittent epidural bolus protocol on physician-administered rescue boluses of labor analgesia

Background Prior studies have shown that programmed intermittent epidural bolus (PIEB) techniques, with or without patient-controlled epidural analgesia (PCEA) boluses, provide better pain relief, reduced motor block, and better patient satisfaction compared to continuous epidural infusion (CEI) techniques. We hypothesized that patients who had labor epidural analgesia (LEA) maintained with PIEB and PCEA would be less likely to receive a physician-administered rescue analgesia bolus compared to patients who had CEI and PCEA. Methods We searched our electronic medical record for patients who had CEI and PCEA from August 1, 2021 to December 31, 2021 and for patients who had PIEB and PCEA from August 2, 2022 to December 31, 2022. Results A total of 792 and 665 patients had maintenance of LEA with CEI/PCEA and PIEB/PCEA, respectively. A multivariate logistic regression was performed and, after adjusting for variables of interest, patients who had PIEB and PCEA were less likely to receive one or more physician-administered rescue analgesia boluses (odds ratio 0.504; 95% confidence interval 0.392, 0.649; P < 0.001) compared to patients who had CEI and PCEA. Conclusion PIEB/PCEA was associated with fewer physician-administered boluses of rescue analgesia compared to CEI/PCEA when used for LEA.

Changes in Sensory Block Level During a Programmed Intermittent Epidural Bolus Regimen for Labor Analgesia: A Prospective Observational Cohort Study

(Can J Anesth/J Can Anesth. 2022;69:1471–1476) Currently, one of the most widely used methods of pain management is epidural analgesia, with drug delivery in a programmed intermittent epidural bolus (PIEB) in conjunction with patient-controlled epidural analgesia. Previously the investigators reported 2 sensory block levels associated with epidural analgesia: (1) upper sensory block level (USBL), the highest dermatome with any altered sensation to cold, and (2) lower sensory block level (LSBL), the highest dermatome with complete sensory block to cold. The purpose of this study was to further explore these sensory block levels and how they change over time with PIEB and patient-controlled epidural analgesia as a pain management method.

A randomized double-blinded study assessing the dose-response of ropivacaine with dexmedetomidine for maintenance of labor with epidural analgesia in nulliparous parturients.

Background: The combination of ropivacaine and dexmedetomidine has been used as an epidural analgesic for inducing labor. However, there is limited data regarding the administration of epidural analgesia for labor maintenance, hence, this study aimed to determine the optimum concentration through dose-response curves of ropivacaine plus dexmedetomidine, which could be used along with the Programmed Intermittent Epidural Bolus (PIEB) technique. Methods: One hundred parturients were randomized into 4 groups who were administered four different doses of ropivacaine (dexmedetomidine at 0.4μgmL-1): 0.04%, 0.06%, 0.08%, and 0.1%. The primary outcome that was determined included the proportion of patients experiencing breakthrough pain during their 1st stage of labor. Breakthrough pain was described as a visual analog scale [VAS] score of >30mm, requiring supplemental epidural analgesia after the administration of at least one patient-controlled bolus. The effective concentration of analgesia that was used for labor maintenance in 50% (EC50) and 90% (EC90) of patients were calculated with the help of probit regression. Secondary outcomes included epidural block characteristics, side effects, neonatal outcomes, and patient satisfaction. Results: The results indicated that the proportion of patients without breakthrough pain was 45% (10/22), 55% (12/22), 67% (16/24), and 87% (20/23) for 0.04%, 0.06%, 0.08%, and 0.10% doses of the analgesic that were administered, respectively. The EC50 value was 0.051% (95% confidence interval [CI], 0.011%-0.065%) while the EC90 value was recorded to be 0.117% (95% CI, 0.094%-0.212%). Side effects were similar among groups. Conclusion: A ropivacaine dose of 0.117% can be used as epidural analgesia for maintaining the 1st stage of labor when it was combined with dexmedetomidine (0.4μgmL-1) and the PIEB technique. Clinical Trial Register: https://www.chictr.org.cn/index.aspx, identifier ChiCTR2200059557.

Comparison of three analgesic regimens in women undergoing cervical brachytherapy

PURPOSEEffective periprocedural analgesia is an important aspect of cervical brachytherapy delivery, with implications for patient comfort and attendance for subsequent fractions. We compared the efficacy and safety of three analgesic modalities: intravenous patient-controlled analgesia (IV-PCA), continuous epidural infusion (CEI) and programmed-intermittent epidural bolus with patient-controlled epidural analgesia (PIEB-PCEA). METHODS AND MATERIALSNinety-seven brachytherapy episodes involving 36 patients between July 2016 and June 2019 in a single tertiary center were retrospectively reviewed. Episodes were divided into two key phases: Phase 1 (while applicator remained in situ) and Phase 2 (following applicator removal until discharge or 4 h). For the primary endpoint, pain scores were retrieved and analyzed by analgesic modality with respect to median score and an internally defined “unacceptable” pain experience (>20% of scores being ≥4/10; i.e., moderate or greater). Total nonepidural oral morphine equivalent dose (OMED) and toxicity/complication events were reported as secondary endpoints. RESULTSIn Phase 1, there was a significantly higher median pain score (p < 0.001) and more episodes with unacceptable pain scores (46%) in the IV-PCA group compared with either epidural modality (6–14%; p < 0.001).In Phase 2, we observed a greater median pain score (p = 0.007) and higher proportion of patient episodes with unacceptable pain scores (38%) in the CEI group compared with both the IV-PCA (13%) and PIEB-PCEA (14%) groups (p = 0.001).There was a significant difference in median OMED used throughout all phases across the PIEB-PCEA (0 mg), IV-PCA (70 mg), and CEI (15 mg) groups (p < 0.001). CONCLUSIONSPIEB-PCEA is safe and offers superior analgesia compared to IV-PCA or CEI for pain control after applicator placement in cervical brachytherapy.

The Incidence of Breakthrough Pain Associated With Programmed Intermittent Bolus Volumes for Labor Epidural Analgesia: A Randomized Controlled Trial

(Int J Obstet Anesth. 2022;51:103571) Previously, ideal programmed intermittent epidural bolus (PIEB) doses were unknown despite the wide belief that use of PIEB may reduce local anesthetic use, improve quality of analgesia and maternal satisfaction, and reduce motor block compared with continuous epidural infusion. This study compared 3 different dosages of a PIEB to determine impact on breakthrough pain and other labor analgesia factors.

Combined Programmed Intermittent Bolus and Patient-Controlled Bolus Is a More Favorable Setting for Epidural Pain Relief Than Continuous Infusion.

Epidural analgesia is a suitable and effective treatment for labor pain. However, the preferable modality setting for delivery remains debatable. This study adopted a programmed intermittent epidural bolus (PIEB) setting in conjunction with a patient-controlled epidural analgesia (PCEA) setting to improve the quality of labor analgesia and reduce the number of medical staff. We conducted a prospective observational analysis of primigravida parturients scheduled for spontaneous labor, which required epidural analgesia for painless labor. A total of 483 healthy primigravida parturients with singleton pregnancies were included in this cohort; 135 nulliparous patients were assigned to the continuous infusion setting (CEI) group and 348 to the PIEB + PCEA group. Compared to the CEI setting, the PIEB + PCEA setting significantly reduced the manual rescue by the clinician, extended the time required for the first manual rescue dose, and acclaimed good maternal satisfaction. The use of the CEI mode increased for poor performance requiring more than two rescues with an odds ratio of 2.635 by a binary logistic regression analysis. Using the PIEB + PCEA setting as the maintenance infusion had a longer duration for the first requested manual rescue, fewer manual rescue boluses, excellent satisfaction, and no significant increase in adverse events compared to the CEI setting.

Determination of the Optimal Volume of Programmed Intermittent Epidural Bolus When Combined With the Dural Puncture Epidural Technique for Labor Analgesia: A Random-Allocation Graded Dose-Response Study.

The dural puncture epidural (DPE) and the programmed intermittent epidural bolus (PIEB) techniques are recent innovations for labor analgesia. The optimal volume of PIEB during traditional epidural analgesia has been investigated previously but it is unknown whether these findings are applicable to DPE. This study aimed to determine the optimal volume of PIEB for effective labor analgesia after initiation of analgesia using DPE. Parturients requesting labor analgesia received dural puncture with a 25-gauge Whitacre spinal needle and then had analgesia initiated with 15 mL of ropivacaine 0.1% with sufentanil 0.5 μg/mL. Analgesia was maintained using the same solution delivered by PIEB with boluses given at a fixed interval of 40 minutes starting 1 hour after the completion of the initial epidural dose. Parturients were randomized to 1 of 4 PIEB volume groups: 6, 8, 10, or 12 mL. Effective analgesia was defined as no requirement for a patient-controlled or manual epidural bolus for 6 hours after the completion of the initial epidural dose or until full cervical dilation. The PIEB volumes for effective analgesia in 50% of parturients (EV50) and 90% of parturients (EV90) were determined using probit regression. The proportions of parturients with effective labor analgesia were 32%, 64%, 76%, and 96% in the 6-, 8-, 10-, and 12-mL groups, respectively. The estimated values for EV50 and EV90 were 7.1 (95% confidence interval [CI], 5.9-7.9) mL and 11.3 (95% CI, 9.9-15.2) mL, respectively. There were no differences in side effects, including hypotension, nausea and vomiting, and fetal heart rate (FHR) abnormalities among groups. Under the conditions of the study, after initiation of analgesia using DPE, the EV90 of PIEB for effective labor analgesia using ropivacaine 0.1% with sufentanil 0.5 μg/mL was approximately 11.3 mL.

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

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. 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. 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 2h and 4h, 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. 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. PROSPERO (CRD42021254978); registered 27 May 2021.

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

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. 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. 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. 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.

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 objectivesTo 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.MethodsIn 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).ResultsThe 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.ConclusionWith 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 registrationChiCTR registration number: ChiCTR2000040917. Registration date: December 15, 2020.

The incidence of breakthrough pain associated with programmed intermittent bolus volumes for labor epidural analgesia: a randomized controlled trial

BackgroundIn this randomized, blinded study, we evaluated the effects of different programmed intermittent epidural bolus (PIEB) volumes for labor analgesia on the incidence of breakthrough pain and other analgesic outcomes. MethodsNulliparous women with term cephalic singleton pregnancies who requested labor analgesia had epidural analgesia initiated with 10 mL 0.1% ropivacaine with sufentanil 0.3 μg/mL. The pump was programmed to deliver a 4, 6 or 8 mL bolus every 45 min (groups 4, 6 or 8, respectively). The primary outcome was the incidence of breakthrough pain, defined as inadequate analgesia after two patient-controlled epidural analgesia administrations in a 20-min period. Secondary outcomes included ropivacaine consumption, time of the first patient-controlled epidural analgesia request, duration of the second stage of labor, and incidence of motor block. ResultsAmong 210 women randomly allocated the incidence of breakthrough pain was 34.9%, 19.7%, and 13.1%, for groups 4, 6 and 8, respectively (P=0.011). The incidence of breakthrough pain in group 8 was lower than in group 4 (P=0.006). The median (interquartile range) hourly ropivacaine consumption was 8.2 mg/h (7.1–11.3), 10.4 mg/h (9.2–13.0), and 12.0 mg/h (11.2–13.8) in groups 4, 6 and 8, respectively (P <0.001). Group 8 had a longer duration of effective analgesia and longer second stage of labor than group 4. There was no significant difference between groups in the incidence of motor block. ConclusionThe larger PIEB volumes were preferred for epidural labor analgesia compared with a smaller volume because of improved analgesia without clinically significant increases in adverse effects.

Neuraxial labor analgesia: Maintenance techniques

Since the advent of neuraxial analgesia for labor, approaches to maintaining intrapartum pain relief have seen significant advancement. Through pharmacologic innovations and improved drug delivery mechanisms, current neuraxial labor analgesia maintenance techniques have been shaped by efforts to maximize patient comfort during the birthing process, while minimizing undesirable side effects and promoting the unimpeded progress of labor. To these ends, a modern anesthesiologist may avail themselves of several techniques, including programmed intermittent epidural bolus (PIEB), patient controlled epidural analgesia (PCEA) and dilute concentration local anesthetic + opioid epidural solutions. We explore the historical development and the evidential underpinnings of these techniques, in addition to several contemporary neuraxial labor analgesia practices. We also summarize current understanding of the effects these interventions have on maternal/fetal health and the labor course, as well as several important aspects of analgesic safety and monitoring.