Programmed intermittent epidural boluses for maintenance of labor analgesia: an impact study

Urinary retention during and after labor with programmed intermittent epidural bolus (PIEB) analgesia: a prospective observational study

BACKGROUND

This study investigates the incidence and risk factors for urinary retention during and after labor in women receiving programmed intermittent epidural bolus (PIEB) analgesia and evaluates the optimal bladder management strategy.

METHODS

This prospective observational study assessed urinary retention during voiding attempts every two to three hours during labor and postpartum, among women with labor epidural analgesia using PIEB. Urinary retention was defined as a post-void residual volume >150 mL, determined by catheterization after spontaneous voiding.

RESULTS

Among 137 women included, with 277 voiding attempts during labor, the urinary retention rate was 20.6%, occurring in 48 women (35%). When the spontaneously voided volume was >50 mL, urinary retention was observed in less than 10% of attempts. Postpartum urinary retention occurred in nine women (6.7%) with a mean post-void residual volume of 1133 ± 447 mL; all were nulliparous, seven had induced labor, and five had an episiotomy.

CONCLUSIONS

Women who are able to successfully void during labor have a low risk of intrapartum urinary retention. We would recommend considering catheterization every 3 to 4 hours for women who are unable to urinate spontaneously, void less than 50 ml, or experience complete motor blockade during labor.

Technical aspects of neuraxial analgesia during labor and maternity care: an updated overview

Labor analgesia is increasingly widespread throughout the world with a rate ranging from 10 to 60%. The benefits regarding clinical and non-clinical maternal-fetal outcomes are currently discussed in international scientific literature. Even stage of labor needs a different and appropriate approach to control the pain; however, different techniques are reported in literature. The following study intends to give a brief overview of the characteristics of the different neuraxial and non-neuraxial techniques currently available and the non-technical skills necessary for effective assistance to pregnant women, providing insights on the topic to understand critical issues at the same time. After bibliographic research since 2018 to 2023, many randomized controlled trials, literature reviews, systematic reviews, and metanalysis were evaluated to create this brief overview. The following pharmacological and non-pharmacological approaches were assessed: spinal techniques, such as epidural analgesia (EA), combined spinal-epidural (CSE), dural puncture epidural (DPE), and continuous spinal anesthesia (CSA); pharmacological administration of nitrous oxide (N2O) and systemic opioids (morphine, fentanyl, and pethidine); as the third one transcutaneous electric nerve stimulation (TENS), acupressure/acupuncture, aromatherapy, and breathing exercises. All the assessed approaches are relatively safe and effective, but the association of technical and non-technical skills is needed to improve the maternal and fetus outcome. More studies are needed to clarify what is the best approach to labor analgesia.

Programmed Intermittent Epidural Boluses of 0.1% Ropivacaine Versus 0.2% Ropivacaine for the Maintenance of Epidural Analgesia in Labor

Objective The gold standard for pain management during labor is epidural analgesia, which can be administered in two different ways to the parturients, either by bolus doses or continuous infusions of local anesthetic solutions with opioids. Recently, programmed intermittent epidural boluses (PIEBs) via a pump are gaining popularity as a very effective method with minimal side effects. The aim of this study was to evaluate the optimum ropivacaine concentration between two different regimens (0.1% or 0.2% both with fentanyl 2 μg/ml) that can provide satisfactory analgesia with the minimum degree of motor blockade, using PIEBs. Methods A prospective randomized controlled study was performed from March 2020 to March 2022. Two different concentrations of ropivacaine 0.1% and 0.2% via PIEBs were equally allocated to two groups of parturients with an additional patient control epidural rescue bolus if needed. Our primary endpoint was motor blockade, as assessed by the modified Bromage scale (MBS). We also recorded visual analog scale (VAS) scores, heart rate, blood pressure, total local anesthetic consumption, labor duration and method of delivery, and APGAR score of the newborns. Results All patients presented Bromage scores equal to 6, and the total consumption of the anesthetic solution was comparable between the two groups. Women in the 0.2% group showed higher pain relief and satisfaction compared to the 0.1% group. Concerning the 0,2% group, diastolic blood pressure and APGAR scores were lower alongside with a lower satisfactory extrusion stage observed by the obstetrician. Conclusion Both ropivacaine regimens provide satisfactory labor epidural analgesia for the expectant mother without any motor blockade.

Comparison of efficacy and safety of three different concentrations of ropivacaine for labor pain management using patient-controlled epidural analgesia (PCEA): A double-blind, randomized controlled trial

Background and Aims

Labor pain is consistently ranked high on the various pain rating scales, when compared to other painful life experiences, and the experience of labor during the process of childbirth is both complex and subjective. Though patient-controlled epidural analgesia (PCEA) using dilute concentrations of local anesthetics (LAs) has been a popular method to control labor pain, yet the optimal dose and regimen for PCEA remain ambiguous. So, the present study was undertaken to evaluate the safety and efficacy of three different concentrations of ropivacaine for labor analgesia using PCEA.

Materials and Methods

Seventy-five healthy nulliparous women who gave voluntary consent for labor analgesia using PCEA were randomly assigned to three groups to receive three different ropivacaine concentrations (0.0625%, 0.1%, and 0.125%) with adjuvant fentanyl 2 μg/ml, after double-blinding. Analgesic efficacy, neuraxial blockade, vital parameters, neonatal outcomes, maternal satisfaction, and side effects were assessed. Primary outcome was total dose of ropivacaine consumed in milligrams.

Results

Number of pain breakthroughs (Visual Analog Score >4) and PCEA demand and rescue boluses were found to be statistically more in group 0.0625% (P < 0.01), followed by group 0.1% and were the least in 0.125%. Still, total drug consumed in milligrams was significantly less in 0.0625% group. Maternal satisfaction was comparable among the three groups (P = 0.33). There was no significant difference in maternal side effects and neonatal APGAR scores among the three groups.

Conclusion

When three different concentrations of ropivacaine, that is, 0.0625%, 0.1%, and 0.125%, are used for labor analgesia, the use of 0.125% ropivacaine leads to higher total amount of ropivacaine consumed. Despite the lower efficacy in terms of breakthrough pain episodes observed with a 0.0625% ropivacaine concentration for labor analgesia, maternal satisfaction remained consistent across all three doses of ropivacaine. PCEA demand and rescue boluses for the lowest concentration, that is, 0.0625%; and did not affect maternal satisfaction with the management of labor pain.

Programmed Intermittent Epidural Bolus Reduces Workloads in Labor Analgesia: A Single Center's Experience

Background and Objectives: Labor epidural analgesia can be maintained through programmed intermittent epidural bolus (PIEB), continuous epidural infusion (CEI), or patient-controlled epidural analgesia (PCEA). Our department changed from CEI+PCEA to PIEB+PCEA as the maintenance method. The higher hourly dose setting in the current regimen brought to our concern that side effects would increase with proportional staff workloads. This study aimed to investigate the validity of our proposal that PIEB+PCEA may function as a feasible tool in reducing the amount of work in the obstetrics anesthesia units. Materials and methods: This 2-year retrospective review included parturients with vaginal deliveries under epidural analgesia. We compared the staff burden before and after the switch from CEI (6 mL/h, PCEA 6 mL lockout 15 min, group A) to PIEB (8 mL/h, PCEA 8 mL lockout 10 min, group B). The primary outcome was the difference of proportion of parturients requiring unscheduled visits between groups. Side effects and labor and neonatal outcomes were compared. Results: Of the 694 parturients analyzed, the proportion of those requiring unscheduled visits were significantly reduced in group B (20.8% vs. 27.7%, chi-square test, p = 0.033). The multivariate logistic regression showed that PIEB was associated with fewer unscheduled visits than CEI (OR = 0.53, 95% CI [0.36-0.80], p < 0.01). Group B exhibited a significantly lower incidence of asymmetric blockade, as well as motor blockade. In nulliparous subjects, obstetric anal sphincter injury occurred less frequently when PIEB+PCEA was used. Significantly more multiparous women experienced vacuum extraction delivery in group B than in group A, and they had a longer second stage of labor. Conclusions: The PIEB+PCEA protocol in our study reduced workloads in labor epidural analgesia as compared to CEI+PCEA, despite that a higher dose of analgesics was administered. Future studies are warranted to investigate the effect of manipulating the PIEB settings on the labor 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).

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

Background

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 0.4 μg/ml at a fixed volume of 10 mL in 90% of subjects (EI90), without the use of patient-controlled epidural analgesia (PCEA).

Methods

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 70 min (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 6 hours after loading dose administration. The PIEB EI90 (95% CI) between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4 μg/ml at a fixed volume of 10 mL was estimated using probit regression.

Results

The effective PIEB interval time between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4 μg/ml at a fixed volume of 10 mL 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.

Conclusion

The estimated value for EI90 for PIEB between boluses of ropivacaine 0.0625% with dexmedetomidine 0.4 μg/ml at a fixed volume of 10 mL 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.

Multimodal Acute Pain Management in the Parturient with Opioid Use Disorder: A Review

The opioid epidemic in the United States has led to an increasing number of pregnant patients with opioid use disorder (OUD) presenting to obstetric units. Caring for this complex patient population requires an interdisciplinary approach involving obstetricians, anesthesiologists, addiction medicine physicians, psychiatrists, and social workers. The management of acute pain in the parturient with OUD can be challenging due to several factors, including respiratory depression, opioid tolerance, and opioid-induced hyperalgesia. Patients with a history of OUD can present in one of three categories: 1) those with untreated OUD; 2) those who are currently abstinent from opioids; 3) those being treated with medications to prevent withdrawal. A patient-centered, multimodal approach is essential for optimal peripartum pain relief and prevention of adverse maternal and neonatal outcomes. Medications for opioid use disorder (MOUD), previously referred to as medication-assisted therapy (MAT), include opioids like methadone, buprenorphine, and naltrexone. These are prescribed for pregnant patients with OUD, but appropriate dosing and administration of these medications are critical to avoid withdrawal in the mother. Non-opioid analgesics such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) can be used in a stepwise approach, and regional techniques like neuraxial anesthesia and truncal blocks offer opioid-sparing options. Other medications like ketamine, clonidine, dexmedetomidine, nitrous oxide, and gabapentinoids show promise for pain management but require further research. Overall, a comprehensive pain management strategy is essential to ensure the well-being of both the mother and the fetus in pregnant patients with OUD.

Programmed intermittent epidural bolus as an ideal method for labor analgesia: a randomized controlled trial

BACKGROUND

Although programmed intermittent epidural bolus (PIEB) is effective for labor analgesia, an appropriate flow rate has not been established. Therefore, we investigated the analgesic effect based on different epidural injection flow rates.

METHODS

Nulliparous women scheduled for spontaneous labor were enrolled in this randomized trial. After injection of intrathecal 0.2% ropivacaine 3 mg with fentanyl 20 μg, participants were randomized to three study groups. Epidural analgesics, 10 ml during one hour, were administered with patient controlled epidural analgesia as follows (0.2% ropivacaine 60 ml, fentanyl 180 μg, and 0.9% saline 40 ml): continuous (n = 28, 10 ml/h for continuous infusion), PIEB (n = 29, 240 ml/h for bolus infusion of 10 ml), or manual (n = 28, 1200 ml/h for bolus injection of 10 ml). The primary outcome was hourly consumption of the epidural solution. The time interval between labor analgesia and the first breakthrough pain was investigated.

RESULTS

The median (Q1, Q3) hourly consumption of epidural anesthetics was significantly different among the groups (continuous: 14.3 [8.7, 16.9] ml, PIEB: 9.4 [6.2, 9.8] ml, manual: 8.6 [7.6, 9.9] ml; P < 0.001). The time to breakthrough pain for the PIEB group was longer than that for the other groups (continuous: 78.5 [35.8, 185.0] min, PIEB: 200.0 [88.5, 441.5] min, manual: 60.5 [37.3, 162.0] min, P = 0.027).

CONCLUSIONS

PIEB, with a low-flow rate, provided more adequate labor analgesia than a continuous epidural infusion or manual injection with a high-flow rate.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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 three analgesic regimens in women undergoing cervical brachytherapy

PURPOSE

Effective 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 MATERIALS

Ninety-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.

RESULTS

In 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).

CONCLUSIONS

PIEB-PCEA is safe and offers superior analgesia compared to IV-PCA or CEI for pain control after applicator placement in cervical brachytherapy.

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.

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.

High Dosage of Patient-Controlled Epidural Analgesia (PCEA) with Low Background Infusion during Labor: A Randomized Controlled Trial

BACKGROUND

Patient-controlled epidural analgesia (PCEA) is well documented; however, it is unclear whether a high dosage of PCEA with a low dosage of background infusion during labor can be a safe and effective application.

METHODS

Group LH was administered a continuous infusion (CI) of 0.084 mL/kg/h with PCEA of 5 mL every 40 min. Group HL was given a CI of 0.028 mL/kg/h and PCEA of 10 mL every 40 min; Group HH was given a CI of 0.084 mL/kg/h and PCEA of 10 mL every 40 min. The primary outcomes were VAS pain score, the number of supplemental boluses, incidence of pain outbreaks, drug dose for pain outbreaks, PCA times, effective PCA times, anesthetic consumption, duration of analgesia, duration of labor and delivery outcome. Secondary outcomes included adverse reactions such as itching, nausea and vomiting during analgesia and neonatal Apgar scores 1 min and 5 min after birth.

RESULTS

A total of 180 patients, 60 in each group were randomly assigned to one of three groups included group LH, group HL or group HH. The VAS scores were obviously decreased in HL group and HH group in comparison with LL group at 2 h after analgesia and the time point of full cervical dilation and delivery of baby. The time for third stage of labor in HH group was increased compared with LH group and HL group. Incidence of pain outbreaks in LH group was obviously increased compared with HL and HH group. The effective PCA times in HL group and HH group were remarkably reduced compared with those in LH group.

CONCLUSIONS

High dose of PCEA with a low background infusion can reduce effective PCA times, incidence of outbreak pain and the total amount of anesthetics without diminishing analgesia effects. However, high dose of PCEA with a high background infusion can enhance analgesia effect but increase the third stage of labor, instrumental delivery ratio and the total amount of anesthetics.

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

BACKGROUND

The dural puncture epidural (DPE) and programmed intermittent epidural bolus (PIEB) techniques are recent advances in neuraxial labor analgesia. Previous studies have investigated the PIEB optimal interval for effective analgesia when a standard epidural technique is used to initiate labor analgesia. However, it is unknown whether these findings are applicable when DPE is used.

METHODS

Patients were randomized into 1 of 5 groups with PIEB intervals of 35, 40, 45, 50, or 55 minutes. Labor analgesia was initiated on request with a DPE technique by epidural injection over 2 minutes of 15 mL of ropivacaine 0.1% with sufentanil 0.5 μg/mL after a dural puncture with a 25-gauge Whitacre needle. Effective analgesia was defined as no additional requirement for a patient-controlled bolus during the first stage of labor. The PIEB interval that was effective in 50% of patients (EI50) and 90% of patients (EI90) was estimated using probit regression.

RESULTS

One hundred laboring parturients received the DPE technique of whom 93 proceeded to have analgesia maintained with PIEB using 10 mL boluses of ropivacaine 0.1% and sufentanil 0.5 μg/mL. Totals of 89.5% (17/19), 84.2% (16/19), 82.4% (14/17), 52.6% (11/19), and 36.8% (7/19) of patients in groups 35, 40, 45, 50, and 55, respectively, received effective PIEB analgesia. The estimated values for EI50 and EI90 were 52.5 (95% CI, 48.4-62.6) minutes and 37.0 (95% CI, 28.4-40.9) minutes, respectively.

CONCLUSION

The estimate of the PIEB optimal interval for effective analgesia after the DPE technique was comparable to that reported in previous studies when analgesia was initiated using a conventional epidural technique.

Comparison of Continuous Infusion of Ropivacaine and Fentanyl With Intermittent Bolus Doses of Ropivacaine and Fentanyl for Epidural Labor Analgesia: A Randomized Open-Label Study

Background

The purpose of this study was to compare the efficacy of continuous epidural infusion with intermittent bolus doses for labour analgesia using ropivacaine 0.2% and opioids.

Methods

In this study, 70 primigravida patients were randomly divided into two groups of 35 each. Both groups received a loading dose of 10ml of 0.2% ropivacaine and 1μg/ml fentanyl in 5ml incremental doses while monitoring blood pressure and heart rate. Subsequently, Group I received a continuous epidural infusion of 0.2% ropivacaine with fentanyl at 10ml/hr, while Group II received 10 ml of 0.2% ropivacaine with fentanyl in bolus form every hour manually, with the first dose given after one hour of the initial loading dose. A rescue bolus dose of 5ml of 0.2% ropivacaine was given in both groups when they complained of breakthrough pain (VAS score >3). An additional 5ml bolus dose was given in both groups at the time of crowning. The blood pressure, heart rate, and severity of pain using the visual analogue scale (VAS) were assessed. Total drug volume utilized, the number of bolus doses, duration of the first and second stage of labour, rate of instrumental delivery and cesarean section, and neonatal Apgar scores were also recorded.

Results

The total volume of drugs consumed and the number of boluses required for breakthrough pain were both significantly lower in Group II. There was a similar decrease in hemodynamic parameters (systolic blood pressure, diastolic blood pressure, and mean arterial pressure) from baseline in both the groups with no significant difference between them. The onset of analgesia was significantly faster in Group I with both groups achieving optimum analgesia (VAS ≤ 3) within 20 minutes of the loading dose. Maternal motor blockade scores, the duration of the first and second stage of labour, the rate of instrumental delivery, cesarean section, and neonatal Apgar scores, did not show any statistically significant difference between the two groups.

Conclusion

Both techniques, i.e. continuous epidural infusion and intermittent epidural boluses are effective for providing labour analgesia. But consumption of drugs and episodes of breakthrough pain was higher in the continuous infusion group (Group I).

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 versus Continuous Epidural Infusion in Major Upper Abdominal Surgery: A Retrospective Comparative Study

Although recent evidence shows that the programmed intermittent epidural bolus can provide improved analgesia compared to continuous epidural infusion during labor, its usefulness in major upper abdominal surgery remains unclear. We evaluated the effect of programmed intermittent epidural bolus versus continuous epidural infusion on the consumption of postoperative rescue opioids, pain intensity, and consumption of local anesthetic by retrospective analysis of data of patients who underwent major upper abdominal surgery under ultrasound-assisted thoracic epidural analgesia between July 2018 and October 2020. The primary outcome was total opioid consumption up to 72 h after surgery. The data of postoperative pain scores, epidural local anesthetic consumption, and adverse events from 193 patients were analyzed (continuous epidural infusion: n = 124, programmed intermittent epidural bolus: n = 69). There was no significant difference in the rescue opioid consumption in the 72 h postoperative period between the groups (33.3 mg [20.0–43.3] vs. 28.3 mg [18.3–43.3], p = 0.375). There were also no significant differences in the pain scores, epidural local anesthetic consumption, and incidence of adverse events. Our findings suggest that the quality of postoperative analgesia and safety following major upper abdominal surgery were comparable between the groups. However, the use of programmed intermittent epidural bolus requires further evaluation.

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.

Labor outcomes with epidural analgesia: an observational before-and-after cohort study comparing continuous infusion versus programmed intermittent bolus plus patient-controlled analgesia

BACKGROUND

Scientific evidence shows that programmed intermittent epidural bolus (PIEB) for labor analgesia achieves good obstetric outcomes. After implementing our institutional standard for epidural analgesia, we compared PIEB + patient-controlled epidural analgesia (PCEA) versus continuous epidural infusion (CEI).

METHODS

In an observational cohort study, we compared CEI with 0.2% ropivacaine + 100-μg fentanyl initial bolus versus PIEB+PCEA with 0.1% ropivacaine + 2 μg mL^-1 fentanyl in primiparous women. The primary outcome was mode of delivery. Secondary outcomes were duration of the second stage of labor and total ropivacaine and fentanyl doses. Other outcomes, in the PIEB+PCEA group only, were motor block, use of PCEA and rescue bolus, maternal mobility and maternal satisfaction. Univariate statistical analysis was performed using the χ² Test, analysis of variance or nonparametric Kruskal-Wallis Test. Multivariate analysis was performed using multiple logistic regression analysis.

RESULTS

The study included 221 patients (CEI 116; PIEB+PCEA 105). Multiple logistic regression showed that the PIEB+PCEA group had significantly fewer caesarean sections (CEI [14%] vs. PIEB+PCEA [5%], P=0.015) and instrumental deliveries, after correcting for confounders (OR=0.49; 95% CI: 0.27-0.89). The second stage of labor did not significantly differ between groups. Total ropivacaine dose was significantly lower with PIEB+PCEA. There was no relationship between mild motor block and increased use of PCEA in the PIEB+PCEA group. Mode of delivery and duration of the second stage of labor were not influenced by motor block either. Maternal satisfaction was high.

CONCLUSIONS

PIEB+PCEA offers obstetric and analgesic advantages over CEI in daily clinical practice.

Comparison of Programmed Intermittent Epidural Boluses With Continuous Epidural Infusion for the Maintenance of Labor Analgesia: A Randomized, Controlled, Double-Blind Study

BACKGROUND

Programmed intermittent epidural boluses may improve the spread of local anesthetics compared to continuous epidural infusion, improving labor analgesia and obstetric outcomes. However, there are limited data from studies using commercially available pumps capable of coadministering programmed intermittent epidural boluses or continuous epidural infusion with patient-controlled epidural analgesia. Therefore, we performed this prospective, randomized, double-blind study to compare the impact of programmed intermittent epidural boluses versus continuous epidural infusion on labor analgesia and maternal/neonatal outcomes. We hypothesized that programmed intermittent epidural boluses will result in lower patient-controlled epidural analgesia consumption compared to that with continuous epidural infusion.

METHODS

Following standardized initiation of epidural labor analgesia, women were randomized to receive 0.1% ropivacaine with 2 µg/mL fentanyl as 6-mL programmed intermittent epidural boluses every 45 minutes or continuous epidural infusion at 8 mL/h in a double-blind fashion with similar patient-controlled epidural analgesia settings in both groups. The primary outcome was patient-controlled epidural analgesia consumption per hour. Secondary outcomes included a need for physician interventions, patterns of patient-controlled epidural analgesia use, motor blockade, number of patients who developed hypotension, pain scores, duration of second stage of labor, mode of delivery, and maternal satisfaction.

RESULTS

We included 120 patients (61 in programmed intermittent epidural boluses group and 59 in continuous epidural infusion group) in the analysis. The median (interquartile range) patient-controlled epidural analgesia volume consumed per hour was not significantly different between the groups: 4.5 mL/h (3.0-8.6 mL/h) for the continuous epidural infusion group and 4.0 mL/h (2.2-7.1 mL/h) for the programmed intermittent epidural boluses group (P = .17). The Hodges-Lehmann location shift estimate of the difference (95% CI) from the continuous epidural infusion to the programmed intermittent epidural boluses group is 0.9 mL/h (-0.4 to 2.2 mL/h). There were also no significant differences between the groups in any of the secondary outcomes except for higher median (interquartile range) patient-controlled epidural analgesia attempts per given ratio per hour in the programmed intermittent epidural bolus group (0.17 [0.10-0.30] vs 0.12 [0.08-0.18]; P = .03) and more motor block in the continuous epidural infusion group (those with Bromage score <5, 27.5% vs 50.0%; P = .03).

CONCLUSIONS

Under the conditions of our study, we did not find improved outcomes with programmed intermittent epidural boluses compared to continuous epidural infusion except for less motor block with programmed intermittent epidural boluses. Future studies should assess whether smaller but clinically important differences exist and evaluate different parameters of programmed intermittent epidural boluses to optimize analgesia and outcomes with this mode of analgesia.

Pain management during labor and vaginal birth

Neuraxial analgesia provides excellent pain relief in labor. Optimizing initiation and maintenance of neuraxial labor analgesia requires different strategies. Combined spinal-epidurals or dural puncture epidurals may offer advantages over traditional epidurals. Ultrasound is useful in certain patients. Maintenance of analgesia is best achieved with a background regimen (either programmed intermittent boluses or a continuous epidural infusion) supplemented with patient-controlled epidural analgesia and using dilute local anesthetics combined with opioids such as fentanyl. Nitrous oxide and systemic opioids are also used for pain relief. Nitrous oxide may improve satisfaction despite variable effects on pain. Systemic opioids can be administered by healthcare providers or using patient-controlled analgesia. Appropriate choice of drug should take into account the stage and progression of labor, local safety protocols, and maternal and fetal/neonatal side effects. Pain in labor is complex, and women should fully participate in the decision-making process before any one modality is selected.

Bolus epidural infusion improves spread compared with continuous infusion in a cadaveric porcine spine model

BACKGROUND

The administration of epidural anesthesia during labor is a common technique used to reduce the pain of childbirth. We sought to compare standard infusion strategies of continuous epidural infusions (CEI) with programmed intermittent epidural bolus (PIEB) to assess the length of spread in terms of vertebral body length. Based on previous clinical data in humans, the PIEB was associated with improved pain control and decreased total dose of local anesthetic. We hypothesized that the PIEB was associated with increased spread when compared with CEI.

METHODS

Thirty female Yorkshire-cross swine cadavers were used to compare three infusion strategies, continuous infusion (CEI) 10 mL/hour programmed continuously, multiple bolus (MB) 2 mL given every 12 min for 10 mL total and 10 mL delivered in a single bolus (SB). Radiographs were used to identify the spread of the radiopaque contrast dye, and a number of vertebral bodies covered were measured to assess spread.

RESULTS

Overall, the CEI had an average spread of 5.6 levels, MB 7.9 and SB 10.4. The differences between SB and MB (p=0.011), SB and CEI (p<0.001) and MB and CEI (p=0.028) were all found to be significant.

CONCLUSIONS

We demonstrated increased spread of epidural contrast with programmed intermittent bolus strategies. This supports previous evidence of improved patient outcomes with PIEB strategy compared with CEI, and encourages the use of PIEB in the appropriate patient population.

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.

A biased coin up-and-down sequential allocation trial to determine the optimum programmed intermittent epidural bolus time interval between 5 mL boluses of bupivacaine 0.125% with fentanyl 2 µg·mL-1

PURPOSE

The optimal epidural mixtures and settings for programmed intermittent epidural bolus (PIEB) labour analgesia have yet to be determined. A previous study by our group demonstrated that 10 mL boluses of bupivacaine 0.0625% with fentanyl 2 µg·mL^-1 administered every 40 min provided effective analgesia during the first stage of labour for 90% of women, without breakthrough pain. We wanted to determine the effective PIEB time interval of 5 mL boluses of bupivacaine 0.125% with fentanyl 2 µg·mL^-1 under the same study circumstances, aiming at a future comparative study.

METHODS

This double-blind dose-finding study used the biased coin up-and-down sequential allocation method to determine the effective PIEB interval 90% (EI90) needed to provide effective analgesia without breakthrough pain during the first stage of labour. We used fixed 5 mL boluses of bupivacaine 0.125% with fentanyl 2 µg.mL^-1 and studied time intervals of 60, 50, 40, and 30 min. The first patient was assigned an interval of 60 min and the remaining intervals were assigned as per the biased coin up-and-down method.

RESULTS

The estimated EI90 was 36.5 min (95% confidence interval [CI], 34.0 to 39.0) by the truncated Dixon and Mood method and 34.2 min (95% CI, 30.8 to 41.5) by the isotonic regression method. We found that 20/40 women had an upper sensory block to ice above T6, 34/40 women had no motor block, and no woman required treatment for hypotension.

CONCLUSION

The EI90 between 5 mL boluses of bupivacaine 0.125% with fentanyl 2 µg·mL^-1 during the first stage of labour is approximately 35 min.

TRIAL REGISTRATION

www.clinicaltrials.gov (NCT #02758405); registered 2 May, 2016.

Neuraxial labor analgesia: a literature review

The use of analgesia techniques for labor has become increasingly frequent, with neuraxial techniques being the most commonly used and most effective. Labor pain entails a number of physiological consequences that may be negative for the mother and fetus, and therefore must be treated. This literature review was performed through a search in the PubMed database, from July to November 2016, and included articles in English or Portuguese, published between 2011 and 2016 or anteriorly, if relevant to the topic. The techniques were divided into the following topics: induction (epidural, combined epidural-spinal, continuous spinal, and epidural with dural puncture) and maintenance of analgesia (continuous epidural infusion, patient-controlled epidural analgesia, and intermittent epidural bolus). Epidural analgesia does not alter the incidence of cesarean sections or fetal prognosis, and maternal request is a sufficient indication for its initiation. The combined technique has the advantage of a faster onset of analgesia; however, patients are subject to a higher incidence of pruritus resulting from the intrathecal administration of opioids. Patient-controlled analgesia seems to be an excellent technique, reducing the consumption of local anesthetics, the number of anesthesiologist interventions, and increasing maternal satisfaction.

Generalisability of randomised trials of the programmed intermittent epidural bolus technique for maintenance of labour analgesia: a prospective single centre cohort study

BACKGROUND

Several randomised controlled trials show that maintenance of labour epidural analgesia with programmed intermittent epidural bolus reduces the maternal motor block compared with maintenance with a continuous infusion. However, these trials were usually restricted to healthy nulliparous parturients. To assess the generalisability of these randomised controlled trials to 'real-world' conditions, we compared maternal motor function (modified Bromage score) over time between healthy nulliparous and parous women using routinely collected quality-control data.

METHODS

After ethical approval, all parturients receiving programmed intermittent epidural bolus labour analgesia between June 2013 and October 2014 were included in this prospective cohort study. Bupivacaine 0.1% with fentanyl 2 μg ml^-1 was used allowing for patient-controlled bolus every 20 min. The maternal motor function (primary outcome) was regularly assessed from insertion of the epidural catheter until delivery.

RESULTS

Of the 839 parturients included, 553 (66%) were nulliparous and 286 (34%) were parous. The parous women had a shorter median duration of epidural analgesia (3 h 59 min vs 5 h 45 min) and a higher incidence of spontaneous delivery (66% vs 37%). The probability of being in a certain Bromage category at birth was similar in nulliparous and parous women in a general additive model adjusting for duration of epidural analgesia, number of rescue top-ups, and number of catheter manipulations (cumulative odds ratio: 1.18; 95% confidence interval: 0.98-1.41). Parous women required a higher time-weighted number and volume of rescue top-ups.

CONCLUSIONS

The results of the randomised controlled trials on a reduced motor block with programmed intermittent epidural bolus seem generalisable to parturients typically not included in these trials.

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

The programmed intermittent epidural bolus (PIEB) technique offers multiple benefits over continuous epidural infusion (CEI), but controversy still exists when it is used in conjunction with a parturient-controlled epidural analgesia (PCEA) regimen. A systematic review and meta-analysis was thus conducted using the Medline, EMBASE, CENTRAL and Web of Science databases with the aim of identifying those randomized controlled trials (RCTs) that performed a comparison between PIEB and CEI in healthy parturients using a PCEA regimen with regard to the duration of labor, labor pain, anesthesia interventions, maternal satisfaction and main side effects. The data were analyzed using a random-effects model. Eleven eligible trials were included, in which 717 participants were allocated to the PIEB + PCEA group and 650 patients were allocated to the CEI + PCEA group. The rate of instrumental delivery, incidence of breakthrough pain, PCEA usage rates and local anesthetic usage were significantly reduced, the labor duration was statistically shorter, and the maternal satisfaction score was significantly improved in the PIEB + PCEA group compared with that in the CEI + PCEA group. There were no differences in the side effects between the two groups. The results of the present study suggest that the PIEB technique in conjunction with the PCEA regimen was more advantageous than CEI + PCEA, but additional studies should be conducted to consistently demonstrate an improvement in the maternal and fetal obstetric outcomes.

[Neuraxial labor analgesia: a literature review]

The use of analgesia techniques for labor has become increasingly frequent, with neuraxial techniques being the most commonly used and most effective. Labor pain entails a number of physiological consequences that may be negative for the mother and fetus, and therefore must be treated. This literature review was performed through a search in the PubMed database, from July to November 2016, and included articles in English or Portuguese, published between 2011 and 2016 or anteriorly, if relevant to the topic. The techniques were divided into the following topics: induction (epidural, combined epidural-spinal, continuous spinal, and epidural with dural puncture) and maintenance of analgesia (continuous epidural infusion, patient-controlled epidural analgesia, and intermittent epidural bolus). Epidural analgesia does not alter the incidence of cesarean sections or fetal prognosis, and maternal request is a sufficient indication for its initiation. The combined technique has the advantage of a faster onset of analgesia; however, patients are subject to a higher incidence of pruritus resulting from the intrathecal administration of opioids. Patient-controlled analgesia seems to be an excellent technique, reducing the consumption of local anesthetics, the number of anesthesiologist interventions, and increasing maternal satisfaction.

A Review of the Impact of Obstetric Anesthesia on Maternal and Neonatal Outcomes

Obstetric anesthesia has evolved over the course of its history to encompass comprehensive aspects of maternal care, ranging from cesarean delivery anesthesia and labor analgesia to maternal resuscitation and patient safety. Anesthesiologists are concerned with maternal and neonatal outcomes, and with preventing and managing complications that may present during childbirth. The current review will focus on recent advances in obstetric anesthesia, including labor anesthesia and analgesia, cesarean delivery anesthesia and analgesia, the effects of maternal anesthesia on breastfeeding and fever, and maternal safety. The impact of these advances on maternal and neonatal outcomes is discussed. Past and future progress in this field will continue to have significant implications on the health of women and children.

Patient intermittent epidural boluses (PIEB) plus very low continuous epidural infusion (CEI) versus patient-controlled epidural analgesia (PCEA) plus continuous epidural infusion (CEI) in primiparous labour: a randomized trial

Epidural maintenance technique for labour analgesia updates constantly. Thanks to infusion pumps, the recently developed programmed intermittent epidural bolus (PIEB) may reduce the use of anesthetic drugs and minimize unintended consequences such as cardio or neurotoxicity. Nevertheless, it is not yet a general practice. So far, there are no comparative studies in the literature that address levobupivacaine-based CEI + PCEA versus CEI + PIEB + PCEA. A randomized double-blind trial was carried out to evaluate if PIEB could reduce local anesthetic use compare to PCEA. Primiparous pregnant patients were divided into two groups: PIEB group (continuous infusion plus intermittent automatic doses) and PCEA group (continuous infusion plus PCEA). The primary objective was to analyze the differences between both groups regarding levobupivacaine total dose. The secondary objectives were to find out the differences concerning pain control, motor blockage, satisfaction score, labour time and delivery outcomes. Statistical analyses were done by protocol. The study recruited 200 patients (103 PIEB, 97 PCEA). The total dose administered was significantly higher in PIEB group: PCEA group 52.97 mg, IC 95% 45.65-60.28 mg and PIEB group 62.04 mg, IC 95% 55.46-68.61 mg (p = 0.021). PIEB group required fewer top up boluses (median value1; range 0-2) than CEI + PCEA group (median value 6; range 3-9) p < 0.05. Satisfaction scores were higher in PIEB group (p = 0.039, CI 95% 1.23-1.42). CEI + PIEB was found to be a good alternative to CEI + PCEA with very high rates of satisfaction in both groups although it was higher in PIEB group. PIEB group required fewer PCEA boluses. Further studies are needed to determine the best approach for epidural pain management.Clinical Trial Number and Registry URL: NCT03133091 ( https://clinicaltrials.gov/ct2/show/NCT03133091?term=MB+Rodriguez&rank=1) .

Programmed intermittent epidural bolus versus continuous epidural infusion for postoperative analgesia after major abdominal and gynecological cancer surgery: a randomized, triple-blinded clinical trial

Background

Continuous epidural infusion (CEI) is the standard application setting for epidural infusion. A new mode, the programmed intermittent epidural bolus (PIEB) technique, showed reduced local anesthetic (LA) consumption and improved analgesia in obstetric analgesia. Goal of this trial was to evaluate the effects of PIEB versus CEI [combined with patient-controlled bolus (PCEA)] on LA consumption and pain scorings in major abdominal cancer surgery.

Methods

Following ethical approval, patients scheduled for major abdominal cancer surgery under general anesthesia in combination with epidural analgesia were randomized to receive either a PIEB mode of 6 mL/h or a CEI mode set at 6 mL/h of ropivacaine 0.2%, both combined with a PCEA mode set at a 4 mL bolus. LA consumptions and pain scorings were documented until the second postoperative evening.

Results

Eighty-four datasets were analyzed (CEI: n = 40, PIEB: n = 44). Regarding the primary endpoint, cumulative LA PCEA bolus volumes until day 2 differed significantly between the groups [PIEB 10 mL (2–28 mL) versus CEI, 28 mL (12–64 mL), median (25th–75th percentiles), p = 0.002]. Overall, LA consumption volumes were significantly lower in the PIEB group versus in the CEI group [PIEB: 329 mL (291–341 mL) vs. CEI: 350 mL (327–381 mL), p = 0.003]. Pain scores were comparable at each time point.

Conclusions

This trial demonstrates reduced needs for PCEA bolus in the PIEB group. There were no clinically relevant benefits regarding morphine consumption, pain scorings, or other secondary outcome parameters.

Trial registration

This study has been registered retrospectively in the ClinicalTrials.gov registry (NCT03378804), date of registration: December, 20th 2017.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0613-6) contains supplementary material, which is available to authorized users.

The optimal concentration of bupivacaine and levobupivacaine for labor pain management using patient-controlled epidural analgesia: a double-blind, randomized controlled trial

BACKGROUND

The study aim was to evaluate the efficacy and safety of different low concentrations of two local anesthetics for labor analgesia using patient-controlled epidural analgesia.

METHODS

A double-blind, randomized controlled trial recruiting healthy nulliparous women was conducted from 2014 to 2017. Epidural analgesia was provided using local anesthetic and fentanyl. Patients were allocated to six groups, according to the concentration of bupivacaine or levobupivacaine (0.0625%, 0.1%, 0.125%). Analgesic efficacy, vital parameters, and side effects were evaluated at different time points. Satisfaction was evaluated using verbal and written scores. The primary outcome was the total dose of local anesthetic used.

RESULTS

Two-hundred-and-thirty-seven cases were analyzed. The total dose of local anesthetic was significantly lower in the two lower concentration groups (P <0.0001). The rate of cesarean section was lower in 0.1% bupivacaine versus 0.1% levobupivacaine (P=0.005), 0.125% levobupivacaine (P=0.049) and 0.125% bupivacaine (P=0.002) groups. Pain breakthrough, patient-controlled and rescue boluses were significantly different between groups (P=0.03, P=0.003 and P <0.0001 respectively). The rate of motor block increased with higher concentrations (P=0.033), but the incidence of other maternal and fetal side effects was not significantly different. Satisfaction with labor analgesia did not differ across groups. Satisfaction score 72 hours after delivery was significantly lower than that two hours after delivery (P <0.0001).

CONCLUSIONS

Higher local anesthetic concentration resulted in higher total doses infused and greater motor block. Labor analgesia was less effective when the lowest concentrations were used, but patient satisfaction was unaffected.

Intrathecal Migration of an Epidural Catheter While Using a Programmed Intermittent Epidural Bolus Technique for Labor Analgesia Maintenance: A Case Report

We describe a case of intrathecal migration of a wire-reinforced epidural catheter in a parturient who received epidural labor analgesia. Epidural analgesia was initiated with a combined-spinal epidural technique and maintained by programmed intermittent epidural boluses. Epidural catheter aspiration after insertion was negative for cerebrospinal fluid. The patient's response to the first four doses of local anesthetic was consistent with epidural drug delivery. After the fifth dose, she developed a complete lower extremity motor block, hypotension, and high sensory blockade. Catheter aspiration was then positive for cerebrospinal fluid. After symptom resolution, labor pain was successfully managed with this inadvertent intrathecal catheter.

The Efficacy of Programmed Intermittent Epidural Bolus for Postoperative Analgesia after Open Gynecological Surgery: A Randomized Double-Blinded Study

BACKGROUND

It is well known that the programmed intermittent epidural bolus (PIEB) technique effectively provides epidural anesthesia in labor. This randomized double-blind trial compared the postoperative analgesic efficacy of PIEB with that of continuous epidural infusion (CEI) in patients undergoing gynecological surgery under combined general-epidural anesthesia.

METHODS

Patients undergoing open gynecological surgery under combined general-epidural anesthesia were randomized at a 1 : 1 ratio to receive PIEB or CEI. In the PIEB group, the pump delivered 4 mL ropivacaine 0.2% plus fentanyl 2 μg/mL every hour. In the CEI group, the pump delivered the same solution at a rate of 4 mL/h. In both groups, additional 4 mL boluses of ropivacaine 0.2% plus fentanyl 2 μg/mL were provided, when necessary, by patient-controlled epidural analgesia after surgery. The primary outcome was the total ropivacaine dose 40 hours after surgery. The secondary outcomes were the number of PCEA boluses and postoperative pain (evaluated on an 11-point numerical rating scale) 3, 24, and 48 hours after surgery.

RESULTS

In total, 57 patients were randomized (n = 28 and 29 in the PIEB and CEI groups, resp.). The two groups differ significantly in terms of the total ropivacaine dose 40 hours after surgery (mean (standard deviation): 155.38 (4.55) versus 159.73 (7.87) mL, P = 0.016). Compared to the CEI group, the PIEB group had significantly lower numerical rating scale scores 3 hours (median [lower-upper quartiles]: 0 [0-0.5] versus 3 [0-5.5], P = 0.002), 24 hours (1 [0-2] versus 3 [1-4], P = 0.003), and 48 hours (1 [0-2] versus 2 [2-3.5], P = 0.002) after surgery.

CONCLUSION

PIEB was better than CEI in terms of providing postoperative analgesia after open gynecological surgery under combined general-epidural anesthesia.

Continuous epidural infusion versus programmed intermittent epidural bolus for labor analgesia: optimal configuration of parameters to reduce physician-administered top-ups

BACKGROUND AND OBJECTIVES

Programmed intermittent epidural bolus (PIEB) is a delivery mode associated with decreased local analgesia dosing, motor block, and physician-administered top-ups (PATUs) during labor analgesia. We hypothesized that PIEB delivery at different settings will result in fewer PATUs for labor analgesia than the same hourly volume of a continuous epidural infusion (CEI).

METHODS

"Before and after" study design of combined spinal-epidural (CSE) for labor, with bupivacaine 0.0625%-fentanyl 2 mcg/ml and patient-controlled epidural analgesia (PCEA; 5 ml bolus with 10 min lock-out). The "before" group (N = 120) received a CEI at 10 ml/hour. PIEB groups received a programmed bolus of 10 ml: every 60 min (PIEB60, N = 120), every 45 min (PIEB45, N = 140), or every 45 min with high flow (500 ml/hour) (PIEB45HF, N = 25).

MAIN OUTCOME MEASURES

Number of women requesting a PATU, time intervals from CSE to PATU and to delivery, and obstetric outcomes.

RESULTS

There was no difference in the proportion of women requesting PATUs between the CEI and PIEB60 groups (45/120 versus 52/120, respectively; p > .05). The PATU rate was lower in the PIEB45 group compared with the PIEB60 and CEI groups (23/140 versus 52/120 and 45/120, p < .005 and p < .05, respectively), and in the PIEB45HF versus PIEB60 groups (5/25 versus 52/120, p < .05). No difference in other outcomes was observed.

CONCLUSIONS

The number of women requesting a PATU was lowest with the PIEB45 and PIEB45HF settings. There were no differences in any other outcomes between groups. This study emphasizes the many variations in programming that need to be further tested to establish the benefits of PIEB delivery compared with traditional CEI with PCEA.

Effect of programmed intermittent epidural boluses and continuous epidural infusion on labor analgesia and obstetric outcomes: a randomized controlled trial

PURPOSE

Continuous epidural infusion and programmed intermittent epidural boluses are analgesic techniques routinely used for pain relief in laboring women. We aimed to assess both techniques and compare them with respect to labor analgesia and obstetric outcomes.

METHODS

After Institutional Review Board approval, 132 laboring women aged between 18 and 45 years were randomized to epidural analgesia of 10 mL of a mixture of 0.1% bupivacaine plus 2 µg/mL of fentanyl either by programmed intermittent boluses or continuous infusion (66 per group). Primary outcome was quality of analgesia. Secondary outcomes were duration of labor, total drug dose used, maternal satisfaction, sensory level, motor block level, presence of unilateral motor block, hemodynamics, side effects, mode of delivery, and newborn outcome.

RESULTS

Patients in the programmed intermittent epidural boluses group received statistically less drug dose than those with continuous epidural infusion (24.9 vs 34.4 mL bupivacaine; P = 0.01). There was no difference between groups regarding pain control, characteristics of block, hemodynamics, side effects, and Apgar scores.

CONCLUSIONS

Our study evidenced a lower anesthetic consumption in the programmed intermittent boluses group with similar labor analgesic control, and obstetric and newborn outcomes in both groups.

Implementation of Programmed Intermittent Epidural Bolus for the Maintenance of Labor Analgesia

Programmed intermittent epidural bolus (PIEB) is an exciting new technology that has the potential to improve the maintenance of epidural labor analgesia. PIEB compared with a continuous epidural infusion (CEI) has the potential advantage of greater spread within the epidural space and therefore better sensory blockade. Studies have demonstrated a local anesthetic-sparing effect, fewer instrumental vaginal deliveries, less motor blockade, and improvements in maternal satisfaction with PIEB compared with CEI. However, the optimal PIEB regimen and pump settings remain unknown, and there are a number of logistical issues and practical considerations that should be considered when implementing PIEB. The PIEB bolus size and interval, PIEB start time delay period, and patient-controlled epidural analgesia bolus size and lockout time can influence the efficacy of PIEB used for epidural labor analgesia. Educating all members of the health care team is critical to the success of the technique. This review summarizes the role of PIEB for the maintenance of labor analgesia, outlines implementation strategies, suggests optimal settings, and presents potential limitations of the technique.

Epidural Analgesia for Labor: Continuous Infusion Versus Programmed Intermittent Bolus

Despite the traditional practice to maintain labor analgesia with a combination of continuous epidural infusion and patient-controlled epidural analgesia using an automated epidural pump; compelling data now shows that bolus injection through the epidural catheter may result in better distribution of anesthetic solution in the epidural space. The programmed intermittent epidural bolus technique is proposed as a better maintenance mode and may represent a more effective mode of maintaining epidural analgesia for labor, especially prolonged labor. Additional prospective and adequately powered studies are needed to confirm findings and determine the optimal combination of volume, rate, time, and drug concentration.