Does programmed intermittent epidural bolus improve childbirth conditions of nulliparous women compared with patient-controlled epidural analgesia?: A multicentre, randomised, controlled, triple-blind study

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).

Influence of different volumes and frequency of programmed intermittent epidural bolus in labor on maternal and neonatal outcomes: A systematic review and network meta-analysis

STUDY OBJECTIVE

In labor, programmed intermittent epidural bolus (PIEB) can be defined as the bolus administration of epidural solution at scheduled time intervals. Compared to continuous epidural infusion (CEI) with or without patient controlled epidural analgesia (PCEA), PIEB has been associated with decreased pain scores and need for rescue analgesia and increased maternal satisfaction. The optimal volume and dosing interval of PIEB, however, has still not been determined.

DESIGN

Systematic review and network meta-analysis registered with PROSPERO (CRD42022362708).

SETTINGS

Labor.

PATIENTS

Pregnant patients.

INTERVENTIONS

Central, CINAHL, Global Health, Ovid Embase, Ovid Medline and Web of Science were searched for randomized controlled trials that examined pregnant patients in labor who received CEI or PIEB with or without a PCEA component. Network meta-analysis was performed with a frequentist method, facilitating the indirect comparison of PIEB with different volumes and dosing intervals through the common comparator of CEI and substituting or supplementing direct comparisons with these indirect ones. Continuous and dichotomous outcomes were presented as mean differences and odds ratios, respectively, with 95% confidence intervals. The risk of bias was evaluated using the Cochrane risk of bias 2 tool.

MAIN RESULTS

Overall, 30 trials were included. For the first primary endpoint, need for rescue analgesia, PIEB delivered at a volume of 4 ml and frequency of 45 min (4/45) was inferior to PIEB 8/45 (OR 3.55; 95% CI 1.12-11.33), PIEB 10/60 was superior to PIEB 2.5/15 (OR 0.36; 95% CI 0.16-0.82), PIEB 4/45 (OR 0.14; 95% CI 0.03-0.71) and PIEB 5/60 (OR 0.23; 95% CI 0.08-0.70), and PIEB 5/30 was not inferior to PIEB 10/60 (OR 0.61; 95% CI 0.31-1.19). For the second primary endpoint, maternal satisfaction, no differences were present between the various PIEB regimens. The quality of evidence for these multiple primary endpoints was low owing to the presence of serious limitations and imprecision. Importantly, PIEB 5/30 decreased the pain score at 4 h compared to PIEB 2.5/15 (MD 2.45; 95% CI 0.13-4.76), PIEB 5/60 (MD -2.28; 95% CI -4.18--0.38) and PIEB 10/60 (MD 1.73; 95% CI 0.31-3.16). Mean ranking of interventions demonstrated PIEB 10/60 followed by PIEB 5/30 to be best placed to reduce the cumulative dose of local anesthetic, and this resulted in an improved incidence of lower limb motor blockade for PIEB 10/60 in comparison to CEI (OR 0.30; 95% CI 0.14-0.67). No differences in neonatal outcomes were found. Some concerns were present for the risk of bias in two thirds of trials and the risk of bias was shown to be high in the remaining one third of trials.

CONCLUSIONS

Future research should focus on PIEB 5/30 and PIEB 10/60 and how the method of analgesia initiation, nature and concentration of local anesthetic, design of epidural catheter and rate of administration might influence outcomes related to the mother and neonate.

Automated mandatory bolus versus basal infusion for maintenance of epidural analgesia in labour

BACKGROUND

Epidural analgesia is often used for pain relief during labour and childbirth, and involves administration of local anaesthetics (LA) into the epidural space resulting in sensory blockade of the abdomen, pelvis, and perineum. Epidural opioids are often co-administered to improve analgesia. Administration of epidural medications can be accomplished by basal infusion (BI) or automated mandatory bolus (AMB). With BI, medications are administered continuously, while AMB involves injecting medications at set time intervals. Patient-controlled epidural analgesia (PCEA) on top of AMB or BI enables patients to initiate additional boluses of epidural medications.  The superior method of delivering epidural medications would result in lower incidence of pain requiring anaesthesiologist intervention (breakthrough pain). Also, it should be associated with lower incidence of epidural-related adverse effects including caesarean delivery, instrumental delivery (use of forceps or vacuum devices), prolonged duration of labour analgesia, and LA consumption. However, clear evidence of the superiority of one technique over the other is lacking. Also, differences in the initiation of epidural analgesia such as combined spinal-epidural (CSE) (medications given into the intrathecal space in addition to the epidural space) compared to epidural only, and medications used (types and doses of LA or opioids) may not have been accounted for in previous reviews.  Our prior systematic review suggested that AMB reduces the incidence of breakthrough pain compared to BI with no significant difference in the incidence of caesarean delivery or instrumental delivery, duration of labour analgesia, and LA consumption. However, several studies comparing AMB and BI have been performed since then, and inclusion of their data may improve the precision of our effect estimates.

OBJECTIVES

To assess the benefits and harms of AMB versus BI for maintaining labour epidural analgesia in women at term.

SEARCH METHODS

We searched CENTRAL, Wiley Cochrane Library), MEDLINE, (National Library of Medicine), Embase(Elseiver), Web of Science (Clarivate), the WHO-ICTRP (World Health Organization) and ClinicalTrials.gov (National Library of Medicine) on 31 December 2022. Additionally, we screened the reference lists of relevant trials and reviews for eligible citations, and we contacted authors of included studies to identify unpublished research and ongoing trials.

SELECTION CRITERIA

We included all randomised controlled studies that compared bolus dosing AMB with continuous BI during epidural analgesia. We excluded studies of women in preterm labour, with multiple pregnancies, with fetal malposition, intrathecal catheters, those that did not use automated delivery of medications, and those where AMB and BI were combined.

DATA COLLECTION AND ANALYSIS

We used standard methodology for systematic review and meta-analysis described by Cochrane. Primary outcomes included: incidence of breakthrough pain requiring anaesthesiologist intervention; incidence of caesarean delivery; and incidence of instrumental delivery. Secondly, we assessed the duration of labour; hourly LA consumption in bupivacaine equivalents, maternal satisfaction after fetal delivery, and neonatal Apgar scores.  The following subgroup analyses were chosen a priori: epidural alone versus CSE technique; regimens that used PCEA versus those that did not; and nulliparous versus combination of nulli- and multi-parous women. We used the GRADE system to assess the certainty of evidence associated with our outcome measures.

MAIN RESULTS

We included 18 studies of 4590 women, of which 13 enrolled healthy nulliparous women and five included healthy nulli- and multiparous women. All studies excluded women with preterm or complicated pregnancies. Techniques used to initiate epidural analgesia differed between the studies: seven used combined spinal epidural, 10 used epidural, and one used dural puncture epidural (DPE). There was also variation in analgesics used. Eight studies utilised ropivacaine with fentanyl, three used ropivacaine with sufentanil, two utilised levobupivacaine with sufentanil, one used levobupivacaine with fentanyl, and four utilised bupivacaine with fentanyl. Most of the studies were assessed to have low risk of randomisation, blinding, attrition, and reporting biases, except for allocation concealment where eight studies were assessed to have uncertain risk and three with high risk. Our results showed that AMB was associated with lower incidence of breakthrough pain compared to BI (risk ratio (RR) 0.71; 95% confidence interval (CI) 0.55 to 0.91; I2 = 57%) (16 studies, 1528 participants), and lower hourly LA consumption in bupivacaine equivalents (mean difference (MD) -0.84 mg/h; 95% CI -1.29 to -0.38, I2 = 87%) (16 studies, 1642 participants), both with moderate certainty. AMB was associated with an estimated reduction in breakthrough pain incidence of 29.1% (incidence 202 per 1000, 95% CI 157 to 259), and was therefore considered clinically significant. The incidence of caesarean delivery (RR 0.85; 95% CI 0.69 to 1.06; I2 = 0%) (16 studies, 1735 participants) and instrumental delivery (RR 0.85; 95% CI 0.71 to 1.01; I2 = 0%) (17 studies, 4550 participants) were not significantly, both with moderate certainty. There was no significant difference in duration of labour analgesia (MD -8.81 min; 95% CI -19.38 to 1.77; I2 = 50%) (17 studies, 4544 participants) with moderate certainty. Due to differences in the methods and timing of outcome measurements, we did not pool data for maternal satisfaction and Apgar scores. Results reported narratively suggest AMB may be associated with increased maternal satisfaction (eight studies reported increased satisfaction and six reported no difference), and all studies showed no difference in Apgar scores. WIth the exception of epidural alone versus CSE which found significant subgroup differences in LA consumption between AMB and BI, no significant differences were detected in the remaining subgroup analyses.

AUTHORS' CONCLUSIONS

Overall, AMB is associated with lower incidence of breakthrough pain, reduced LA consumption, and may improve maternal satisfaction. There were no significant differences between AMB and BI in the incidence of caesarean delivery, instrumental delivery, duration of labour analgesia, and Apgar scores. Larger studies assessing the incidence of caesarean and instrumental delivery are required.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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