Patient-controlled Epidural Analgesia following Combined Spinal-epidural Analgesia in Labour: The Effects of Adding a Continuous Epidural Infusion

Bibliometric Analysis on Global Analgesia in Labor from 2002 to 2021

Background

Maternal pain during labor is one of the most important factors contributing to increased cesarean delivery rates and poor pregnancy outcomes, and this pain can be managed by labor analgesia. Many studies exist on labor analgesia, and the quantity and quality of these studies have not been reported. Therefore, we aimed to perform a bibliometric analysis of studies from 2002 to 2021.

Methods

We used the Web of Science database to obtain publications related to labor analgesia from January 2002 to December 2021. Various bibliographic information was collected, including country; author; journal; grant; discipline; institution and research hotspot. A total of 4536 papers were included.

Results

A total of 4536 articles were included in the study. The country with the most published articles on labor analgesia and the country of the funding agency was the United States. Most articles were published in the disciplines Anesthesiology and Obstetrics & Gynecology. The journal that published the most articles in this category was International Journal of Obstetric Anesthesia. In addition, we found different research hotspots for labor analgesia in the United States, Japan, and China.

Conclusion

This paper provides a bibliometric analysis of research on labor analgesia and highlights the differences in research hotspots for labor analgesia between countries.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

STUDY REGISTRATION

PROSPERO (CRD42021254978); registered 27 May 2021.

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.

[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) .

[Recent standards in management of obstetric anesthesia]

The following article contains information not only for the clinical working anaesthesiologist, but also for other specialists involved in obstetric affairs. Besides a synopsis of a German translation of the current "Practice Guidelines for Obstetric Anaesthesia 2016" [1], written by the American Society of Anesthesiologists, the authors provide personal information regarding major topics of obstetric anaesthesia including pre-anaesthesia patient evaluation, equipment and staff at the delivery room, use of general anaesthesia, peridural analgesia, spinal anaesthesia, combined spinal-epidural anaesthesia, single shot spinal anaesthesia, and programmed intermittent epidural bolus.

Practice Guidelines for Obstetric Anesthesia

The American Society of Anesthesiologists Committee on Standards and Practice Parameters and the Task Force on Obstetric Anesthesia and the Society for Obstetric Anesthesia and Perinatology present an updated report of the Practice Guidelines for Obstetric Anesthesia.

Supplemental Digital Content is available in the text.

Comparison of computer-integrated patient-controlled epidural analgesia with no initial basal infusion versus moderate basal infusion for labor and delivery: A randomized controlled trial

Background and Aims:

Computer-integrated patient-controlled epidural analgesia (CIPCEA) is a novel epidural drug delivery system. It automatically adjusts the basal infusion based on the individual's need for analgesia as labor progresses.

Materials and Methods:

This study compared the time-weighted local anesthetic (LA) consumption by comparing parturients using CIPCEA with no initial basal infusion (CIPCEA0) with CIPCEA with initial moderate basal infusion of 5 ml/H (CIPCEA5). We recruited 76 subjects after ethics approval. The computer integration of CIPCEA titrate the basal infusion to 5, 10, 15, or 20 ml/H if the parturient required respectively, one, two, three, or four patient demands in the previous hour. The basal infusion reduced by 5 ml/H if there was no demand in the previous hour. The sample size was calculated to show equivalence in LA consumption.

Results:

The time-weighted LA consumption between both groups were similar with CIPCEA0 group (mean [standard deviation (SD)] 8.9 [3.5] mg/H) compared to the CIPCEA5 group (mean [SD] 9.9 [3.5] mg/H), P = 0.080. Both groups had a similar incidence of breakthrough pain, duration of the second stage, mode of delivery, and patient satisfaction. However, more subjects in the CIPCEA0 group required patient self-bolus. There were no differences in fetal outcomes.

Discussion:

Both CIPCEA regimens had similar time-weighted LA consumption and initial moderate basal infusion with CIPCEA may not be required.

Modern neuraxial labor analgesia: options for initiation, maintenance and drug selection

In the present review we outline the state-of-the-art of neuraxial analgesia. As neuraxial analgesia remains the gold standar of analgesia during labor, we review the most recent literature on this topic. The neuraxial analgesia techniques, types of administration, drugs, adjuvants, and adverse effects are investigated from the references. Most authors would agree that central neuraxial analgesia is the best form to manage labor pain. When neuraxial analgesia is administered to the parturient in labor, different management choices must be made by the anesthetist: how will we initiate analgesia, how will analgesia be maintained, which local anesthetic will we use for neuraxial analgesia and which adjuvant drugs will we combine? The present manuscript tries to review the literature to answer these questions.

A randomized controlled trial of three patient-controlled epidural analgesia regimens for labor

BACKGROUND

Patient-controlled epidural analgesia (PCEA) is a safe and effective mode of maintaining labor analgesia; however, the ideal PCEA regimen is controversial.

METHODS

In this prospective, randomized, double-blind study, we examined the analgesic efficacy of demand-only PCEA and PCEA with background infusion. We recruited 300 nulliparous parturients. Analgesia was initiated with intrathecal ropivacaine 2 mg and fentanyl 15 microg and maintained with epidural ropivacaine 0.1% with fentanyl 2 microg/mL. Parturients were randomized to one of three groups. Group 0: demand-only PCEA, bolus of 5 mL, lockout interval of 15 min. Group 5: background infusion of 5 mL/h, bolus of 5 mL, lockout interval of 12 min. Group 10: background infusion of 10 mL/h, bolus of 5 mL, lockout interval of 10 min. The maximum dose of all groups was 20 mL/h. The primary outcome was incidence of breakthrough pain. Secondary outcomes included intrapartum pain scores, neuraxial blockade characteristics, side effects, the total and hourly volume of ropivacaine, neonatal outcomes, and obstetric outcomes.

RESULTS

The incidence of breakthrough pain and the maximum visual analog scale (0-100 mm scale) pain scores were higher in Group 0 versus Groups 5 and 10 (43% vs 17% and 11%, P < 0.001 and 37 +/- 28 vs 22 +/- 26 and 16 +/- 25 [mean +/- SD], P < 0.001), respectively. Group 10 had a longer duration of effective analgesia compared with Group 0 (mean 895 min, 95% CI 823-966 vs 565 min, 95% CI 454-677, P < 0.001) and increased ropivacaine consumption, and was associated with a longer duration of the second stage of labor.

CONCLUSION

Demand-only PCEA (5-mL bolus, 15-min lockout interval) resulted in less local anesthetic consumption but an increased incidence of breakthrough pain, higher pain scores, shorter duration of effective analgesia, and lower maternal satisfaction, when compared with PCEA with background infusion (5-mL bolus, 10-12-min lockout interval, and 5-10 mL/h infusion).

A double-blind randomized controlled trial of patient-controlled epidural analgesia with or without a background infusion following initial spinal analgesia for labor pain

BACKGROUND

Patient-controlled epidural analgesia (PCEA) combined with spinal analgesia is an option for pain relief in labor. However, the effect of a CBI on the analgesic requirements of laboring women is still debated. This double-blind study investigated the effect of CBI with PCEA following spinal analgesia on the local anesthetic requirements of parturients during labor.

METHODS

Sixty-six nulliparous women were randomly assigned to a standard PCEA protocol (5-mL demand bolus, 10-min lockout) with or without a CBI of 6 mL/h. The epidural solution consisted of 0.1% ropivacaine with fentanyl 2 microg/mL. Labor analgesia was initiated in both groups with intrathecal bupivacaine 2.5 mg plus fentanyl 25 microg. The number of demands per hour and the hourly dose of ropivacaine were calculated for both groups.

RESULTS

The median [range] number of analgesic boluses per hour in the PCEA group that were demanded: 2.4 [0.8-12.2] and delivered: 1.6 [0.8-2.6], were significantly greater than those in the PCEA+CBI group: 0.7 [0.4-4.2] and 0.6 [0.2-1.3] (P 0.05). However, the hourly ropivacaine dose in the PCEA group (7.9 [3.9-13.2] mg/h) was not significantly different from that in the PCEA+CBI group (8.4 [6.0-12.5] mg/h).

CONCLUSION

In laboring nulliparous patients provided initial labor analgesia with spinal anesthesia, the use of a continuous background infusion decreases PCEA demand dosing, but not the total hourly amount of ropivacaine and fentanyl used.

A Comparison of a Basal Infusion with Automated Mandatory Boluses in Parturient-Controlled Epidural Analgesia During Labor

BACKGROUND

The use of parturient-controlled epidural analgesia (PCEA) with a basal infusion is commonly used in laboring women. We compared a novel approach of providing basal intermittent boluses concurrently with PCEA: PCEA plus automated mandatory boluses (PCEA+AMB) versus PCEA plus basal continuous infusion (PCEA+BCI). We hypothesized that epidural local anesthetic consumption would be lower if basal intermittent boluses were used instead of a basal infusion.

METHODS

We randomized 42 healthy parturients in early labor to receive 0.1% ropivacaine + fentanyl 2 microg/mL either via PCEA+BCI (n = 21,bolus 5 mL, lockout 10 min, basal infusion 5 mL/h) or via PCEA+AMB (n = 21, patient-activated bolus of 5 mL, lockout 10 min, basal automated boluses of 5 mL/h [omitted if a patient-activated bolus was successfully administered in the last 1 h]) after successful induction of combined spinal epidural analgesia.

RESULTS

We found a reduction in the hourly consumption of ropivacaine with PCEA+AMB, i.e., the primary outcome measure (mean = 6.5 mL, sd = 3.4 in the PCEA+AMB group vs 7.5 mL, sd = 2.0 PCEA+BCI group, P = 0.011). A larger proportion of parturients in the PCEA+AMB group did not self-bolus (6/21 vs 1/21 in PCEA+BCI, P = 0.03). The time to the first self-bolus after combined spinal epidural was longer in the PCEA+AMB group (mean survival time 315 min vs 190 min in PCEA+BCI group, P = 0.04 by log rank test). There was no difference in pain scores or side effects.

CONCLUSION

Our study showed that PCEA+AMB reduced analgesic consumption and could be useful as the mode of maintenance for epidural analgesia.

Comparison of computer integrated patient controlled epidural analgesia vs. conventional patient controlled epidural analgesia for pain relief in labour

Computer integrated-patient controlled epidural analgesia (CI-PCEA) is a novel drug delivery system. It automatically titrates the background infusion rate based on the individual parturient's need. In this randomised trial, we compared the local anaesthetic consumption by parturients using CI-PCEA with demand only patient controlled epidural analgesia (PCEA) for labour analgesia. We recruited 40 parturients after approval by the ethics committee. Group PCEA (n = 20) received demand only PCEA. Group CI-PCEA (n = 20) received a similar PCEA regimen but the computer integration titrated the background infusion to 5, 10 or 15 ml x h(-1) if the patient required one, two or three demand boluses, respectively, in the previous hour. The background infusion decreased by 5 ml x h(-1) if there was no demand bolus in the previous hour. The sample size was calculated to show equivalence in local anaesthetic used. The time weighted consumption of local anaesthetic was similar in both groups (mean difference 0.7 mg x h(-1), 95% confidence interval [CI: -2.5, 1.1]; p = 0.425). The CI-PCEA group had higher maternal satisfaction scores: mean (SD) 93 (7) vs. 86 (11), p = 0.042. CI-PCEA does not increase the use of local anaesthetic when compared with demand only PCEA but does increase patient satisfaction.