Remifentanil as an alternative to epidural analgesia for vaginal delivery: A meta-analysis of randomized trials

Comparative efficacy of opioid and non-opioid analgesics in labor pain management: A network meta-analysis

BACKGROUND

Effective labor pain management is crucial for parturient well-being, as it can improve the delivery experience of pregnant women and reduce anxiety and tension. This systematic review and network meta-analysis compared the efficacy and safety of various analgesics, classified by drug category and individual treatment methods, for labor pain control.

METHODS

A comprehensive literature search was conducted in Pubmed, EMBASE, Cochrane Library, and Web of Science databases. All searches commenced from the database's inception to the date of the literature search (May 31, 2023). The Cochrane Risk of Bias 2 tool assessed study bias risk. Network meta-analyses using a random-effects model and odds ratios (ORs) with 95% confidence intervals (CIs) were performed.

RESULTS

Fifteen randomized controlled trials evaluating analgesic interventions in ASA I or II parturients were included. Combination therapies (OR: 5.81; 95% CI, 3.76-7.84; probability: 60%) and non-opioid analgesics (OR: 5.61; 95% CI, 2.91-8.30; probability: 39.2%) were superior to placebo for labor pain relief. Specifically, dexmedetomidine/ropivacaine/sufentanil (OR: 7.32; 95% CI, 2.73-11.89; probability: 40.6%) and dexmedetomidine/ropivacaine (OR: 6.50; 95% CI, 2.51-10.33; probability: 11.9%) combinations, bupivacaine/fentanyl and ropivacaine/sufentanil combinations, and remifentanil monotherapy showed improved analgesic efficacy versus placebo. Dexmedetomidine/ropivacaine reduced parturient nausea and vomiting versus alternatives.

CONCLUSION

Non-opioids, opioids and combinations thereof effectively relieved labor pain. In addition, dexmedetomidine/ropivacaine combination demonstrated analgesic efficacy and lower nausea and vomiting incidence.

Factors influencing the use of epidural labor analgesia: a cross-sectional survey analysis

Introduction

This study aimed to explore the personal and organizational factors influencing the lack of implementation of epidural labor analgesia (ELA).

Methods

This study was conducted at the Shanghai First Maternity and Infant Hospital, School of Medicine, Tongji University, Shanghai, China. A total of 451 women who underwent vaginal delivery without ELA between 8 October 2021 and 30 March 2022, were included. A questionnaire was used to collect the relevant data. We derived and validated the variable, without ELA, by using binary logistic regression analysis.

Results

Of the total 451 included, 355 (78.7%) initially preferred ELA, whereas 96 (21.3%) rejected it directly. Five variables were validated (p < 0.05): multiparas, ELA would lead to back pain, experienced ELA in previous delivery, the inner attitude toward labor pain, and blood routine and coagulation function not being tested within 14 days. The sensitivity and specificity of this model were 96.3 and 69.8%, respectively.

Conclusion

The corresponding training should be provided to the medical staff to identify women at high risk of rejecting ELA during the prenatal examination process using a questionnaire, then provide them with knowledge regarding ELA, so that ELA can benefit more mothers. Additionally, the existing organizational factor should be addressed in order to efficiently provide ELA services to mothers.

Clinical trial registration

This study was registered at the Chinese Clinical Trial Registry (Chi CTR 2000034625) on July 12, 2020.

Efficacy and Safety of Transcutaneous Electrical Acupoint Stimulation (TEAS) As An Analgesic Intervention for Labor Pain: A Network Meta-analysis of Randomized Controlled Trials

INTRODUCTION

Epidural analgesia (EA) is the most widely used intervention for the reduction of labor pain; however, it is contra-indicated for patients with spinal deformity or allergy to anesthetics and may be refused by parturients. As a noninvasive and nonnarcotic analgesic intervention, transcutaneous electrical acupoint stimulation (TEAS) has gained increasing attention in recent years. Therefore, we performed a network meta-analysis to compare the efficacy and safety of TEAS and EA as measured by visual analog scale score, the failure rate of natural delivery, adverse events, and Apgar scores.

METHODS

Relevant randomized controlled trials (RCTs) from four electronic databases (PubMed, EMBASE, Web of Science, and Cochrane CENTRAL) and clinical trials.gov were searched from inception until September 4, 2022. A random effects model was used during analysis, and outcomes were evaluated as standard mean difference (SMD), odds ratio (OR), and 95% confidence intervals (CrI) using STATA (version SE15.0), R (version 3.6.1), and ADDIS (version 1.16.8) software.

RESULTS

Ten RCTs comprising 1214 parturients were identified by screening. Six RCTs compared TEAS and controls, three compared EA and controls, and one compared TEAS and EA. No heterogeneity was found within the four outcomes. There was no significant difference in any outcomes between interventions or control treatments in terms of SMD, OR, and CrI. Combined with the highest surface under the cumulative ranking curve score, TEAS demonstrated possible better effects in the aspects of analgesic efficacy and safety under certain circumstances.

CONCLUSIONS

TEAS may be a potential alternative for parturients as a simple, noninvasive, and non-pharmacological intervention compared with EA in terms of analgesic efficacy and safety for mothers and neonates.

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.

The effects of intravenous remifentanil on umbilical artery serum-derived exosomes in parturients undergoing epidural anesthesia: a randomized trail

BACKGROUND

Umbilical artery serum-derived exosomes (UEs) serve as messengers for maternal-fetal information exchange and cellular regulation. Intravenous remifentanil could be considered as an effective adjunct to epidural anesthesia in providing a favorable analgesia effect for cesarean section (C-section), but its effects on UEs are currently unknown.

METHODS

From 01/12/2021 to 30/06/2022, eligible parturients scheduled for repeated C-section at the First Affiliated Hospital of Wenzhou Medical University were randomized to receive either an intravenous bolus (0.15 μg/kg) followed by a continuous infusion (0.075 μg/kg/min) of remifentanil or normal saline throughout the procedure. The primary outcome was the number of UEs. Secondary outcomes included the size and protein amount of UEs, the vital signs, visceral pain score, sedation score, maternal satisfaction score, Apgar score, the incidence of neonatal asphyxia, umbilical arterial pH, and the presence of complications.

RESULTS

Nanoparticle tracking analysis indicated similar size of UEs between the two groups, but the number and protein amount of UEs were increased in the remifentanil group  compared to the control group (P < 0.05). In parturients receiving remifentanil, visceral pain scores were decreased, which was accompanied by the increased scores of maternal satisfaction with the anesthetic method (P < 0.05). Other maternal and neonatal outcomes were comparable between the two groups (P > 0.05).

CONCLUSION

The intravenous administration of remifentanil increased the number of UEs in parturients undergoing repeated C-section under epidural anesthesia, with improved birth experience and minimal neonatal complications.

The efficacy and safety of remifentanil patient-controlled versus epidural analgesia in labor: A meta-analysis and systematic review

BACKGROUND

Remifentanil patient-controlled analgesia (rPCA) and epidural analgesia (EA) has been used for pain relief in labor. We aimed to evaluate the efficacy and safety of rPCA versus EA in labor, to provide evidence support for clinical analgesia and pain care.

METHODS

We searched PubMed, EMBASE, ScienceDirect, Cochrane Library, China National Knowledge Infrastructure (CNKI), Wanfang and Weipu databases for RCTs comparing rPCA and EA in labor until February 15, 2022. Two researchers independently screened literature and extracted data. RevMan 5.3 software was used for data analysis.

RESULTS

A total of 10 RCTs involving 3086 parturients were enrolled, 1549 parturients received rPCA and 1537 received EA. Meta-analysis indicated that the incidence of intrapartum maternal fever within 1 hour of labor analgesia (OR = 0.43, 95%CI: 0.30~0.62), after 1 hour of labor analgesia (OR = 0.42, 95%CI: 0.20~0.90) in the rPCA was significantly less than that of EA (all P<0.05). The incidence of respiratory depression (OR = 3.56, 95%CI: 2.45~5.16, P<0.001) in the rPCA was significantly higher than that of EA. There were no significant differences in the incidence of Apgar scores<7 at 5 minutes (OR = 1.18, 95%CI: 0.71~1.96, P = 0.53), the patients' satisfaction of pain relief during labor analgesia (SMD = 0.03, 95%CI: -0.40~0.46, P = 0.90) between rPCA and EA (all P>0.05).

CONCLUSION

rPCA can be an optional alternative to EA with similar pain relief and less risk of intrapartum maternal fever. However, rPCA was associated with increased risk of respiratory depression. Future studies with rigorous design and larger sample size are needed to provide more reliable evidences for clinical rPCA and EA use.

Effect and Safety of Remifentanil Patient-Controlled Analgesia Compared with Epidural Analgesia in Labor: An Updated Meta-Analysis of Randomized Controlled Trials

PURPOSE

The study was aimed to systematically assess the effect and safety of remifentanil patient-controlled analgesia (rPCA) versus epidural analgesia (EA) during labor.

METHODS

Eligible trials were retrieved from PubMed, EMBASE, ScienceDirect, and Cochrane Library before April 2020. The primary outcomes were patient satisfaction with pain relief and average visual analog scale (VAS) pain scores during labor; the secondary outcomes were rate of spontaneous delivery, oxygen desaturation, maternal hyperthermia, and neonatal Apgar scores <7 at 1 and 5 min.

RESULTS

Eleven studies involving 3,039 parturients were included. We found that parturients receiving rPCA were similarly satisfied with pain relief compared to those receiving EA (standardized mean difference: -0.19; 95% confidence interval [CI]: -0.57, 0.18), though had significantly higher VAS pain scores during labor (weighted mean difference: 1.41; 95% CI: 0.32, 2.50). The rate of spontaneous delivery was comparable. rPCA increased the risk of maternal oxygen desaturation (risk ratio [RR]:3.23, 95% CI: 1.98, 5.30). There was no statistical significance regarding hyperthermia (RR: 0.49, 95% CI: 0.24, 1.01). No significant difference was found for neonatal Apgar scores <7 at 1 and 5 min.

CONCLUSION

rPCA could be an optional alternative for pain relief to EA without worsening maternal satisfaction with pain relief, delivery modes, or neonatal morbidity. However, rPCA was associated with higher pain intensity during labor and higher incidence of maternal oxygen desaturation. The routine use of rPCA in labor must be armed with close respiratory monitoring. Continued well-designed studies are required to provide more robust evidence.

COVID in obstetrics: labor analgesia and cesarean section

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Remifentanil for Carboprost-Induced Adverse Reactions During Cesarean Delivery Under Combined Spinal-Epidural Anesthesia

Purpose

Carboprost may induce adverse reactions when used to treat postpartum hemorrhage. We aimed to explore the effects of intravenous infusion of low-dose remifentanil to prevent such reactions.

Methods

We enrolled parturient patients scheduled for elective cesarean section. Anesthesiologist administered combined spinal epidurals at the L3/4 interspace, with 0.5% hyperbaric bupivacaine subarachnoid space injections (1.5–2.5 ml). We randomly divided parturient patients, administered carboprost during surgery, into the remifentanil group (group R) and the control group (group C). Patients in group R received an intravenous target-controlled infusion of remifentanil (target effect-site concentration, 1.5 ng/ml) simultaneously with a carboprost tromethamine injection (250 µg). Patients in group C received a normal saline infusion with carboprost. We recorded and analyzed the incidence of carboprost-related adverse reactions (vomiting, nausea, chest congestion, flushing, hypertension, tachycardia, cough, and shivering), and assessed patient comfort using a numerical rating scale ([NRS], on which 0 was very uncomfortable and 10 was very comfortable).

Results

After applying inclusion and exclusion criteria, we conducted statistical analysis of the data from 70 women. The incidence of vomiting was significantly lower in group R than in group C (14.3 vs. 51.4%, p < 0.01); and the incidence of nausea, chest congestion, facial flushing, and hypertension were significantly lower in group R than in group C (all p < 0.01). Furthermore, the patients’ comfort scores were significantly higher in group R than in group C (8.0 ± 1.8 vs. 3.6 ± 2.1, p < 0.01).

Conclusion

Our results demonstrate that an intravenous low-dose remifentanil infusion can effectively prevent carboprost-related adverse reactions during cesarean delivery under combined spinal and epidural anesthesia.

Clinical Trial Registration

We pre-registered this study at http://www.chictr.org.cn/showproj.aspx?proj=27707 (ChiCTR1800016292).

Remifentanil patient-controlled versus epidural analgesia on intrapartum maternal fever: a systematic review and meta-analysis

Background

Intravenous remifentanil patient-controlled analgesia (RPCA) is an alternative for epidural analgesia (EA) in labor pain relief. However, it remains unknown whether RPCA is superior to EA in decreasing the risk of intrapartum maternal fever during labor.

Methods

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, a systematic review and meta-analysis was performed by searching PubMed, EMBASE and the Cochrane Central Register of Controlled Trials from inception to April 2019. All randomized controlled trials (RCTs) investigating the risk of intrapartum maternal fever with RPCA compared with EA alone or EA in combination with spinal analgesia during labor were included.

Results

A total of 825 studies were screened, and 6 RCTs including 3341 patients were identified. Compared with EA, RPCA was associated with a significantly lower incidence of intrapartum maternal fever (risk ratio [RR] 0.48, P = 0.02, I² = 49%) during labor analgesia. After excluding 2 trials via the heterogeneity analysis, there was no difference in the incidence of intrapartum fever between patients receiving RPCA and those receiving EA. Satisfaction with pain relief during labor was lower in the RPCA group than that in the EA group (− 10.6 [13.87, − 7.44], P < 0.00001, I² = 0%). The incidence of respiratory depression was significantly greater in the RPCA group than that in the EA group (risk ratio 2.86 [1.65, 4.96], P = 0.0002, I² = 58%). The incidence of Apgar scores < 7 at 5 min in the RPCA group was equivalent to that in the EA group.

Conclusion

There is no solid evidence to illustrate that the incidence of intrapartum maternal fever is lower in patients receiving intravenous RPCA than in patients receiving EA.

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.

Continuous intravenous infusion of remifentanil improves the experience of parturient undergoing repeated cesarean section under epidural anesthesia, a prospective, randomized study

Background

Unsatisfactory analgesia would occur frequently during repeated cesarean section under epidural anesthesia. The aim of this study is to observe the effects of intravenous remifentanil on maternal comfort, maternal and neonatal safety during repeated cesarean section under epidural anesthesia.

Methods

A total of 80 parturients undergoing repeated cesarean section were involved in the study. The patients were randomly divided into the intravenous remifentanil- assisted epidural group (group R) and epidural group (group E), respectively (n = 40). In group R, the remifentanil was continuously intravenously infused as an adjuvant to epidural anesthesia. In group E, 0.75% ropivacaine epidural or intravenous ketamine was administered as needed. Parturient baseline characteristics, vital signs, VAS scores, and comfort scores during surgery were recorded. Adverse effects were also recorded.

Results

A total of 80 patients were enrolled in the current study and the final analyses included 39 patients in group R and 38 patients in group E. No differences in patients’ baseline characteristics were found between the two groups (p > 0.05). Compared with group E, the comfort score was significantly higher in group R (9.1 ± 1.0 vs. 7.5 ± 1.3, p <  0.001), whereas the maximum VAS score was significantly lower in group R (1.8 ± 1.2 vs. 4.1 ± 1.0, p <  0.001). Maternal and neonatal adverse effects did not differ between the two groups during surgery (p > 0.05).

Conclusions

Continuous intravenous infusion of low-dose remifentanil can significantly improve the experience of parturients undergoing repeated cesarean section under epidural anesthesia, without noticeable maternal or neonatal adverse effects.

Trial registration

This study was pre-registered at http://www.chictr.org.cn/index.aspx (ChiCTR1800018423) on 17/09/2018.

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.

Safety and efficacy of a combination of pethidine and levallorphan for pain relief during labor: An observational study

AIM

To evaluate the safety, effect on breastfeeding and efficacy of a combination of pethidine and levallorphan (Pethilorfan) for pain relief during labor.

METHODS

We compared maternal or neonatal morbidities, suckling difficulties in newborns and breastfeeding rates between 177 women who received 50-200 mg (as pethidine) of Pethilorfan during labor (Pethilorfan group) and 354 women who delivered their infants without analgesic drugs immediately before or after each woman in the Pethilorfan group (control group) from January 1, 2005 to December 31, 2016. We performed univariate and multivariate analyses for comparison between the two groups. We also evaluated the efficacy of Pethilorfan retrospectively.

RESULTS

The Pethilorfan group included more women with prolonged and/or operative deliveries than the control group. Nevertheless, no significant differences were seen between the two groups in the rates of Apgar scores less than 7 at 1 or 5 min, composite neonatal morbidities, hyperbilirubinemia or respiratory disturbances. The incidence of suckling difficulties lasting over 24 h and the breastfeeding rates at discharge or after 1 month were also similar. Maternal adverse effects of Pethilorfan were generally mild and transient. The efficacy ratio of Pethilorfan was 83.6%, although its analgesic effect was usually incomplete.

CONCLUSION

Pethilorfan can be used safely for labor pain relief without increasing maternal or neonatal morbidities, or impeding breastfeeding, if it is administered at a prudent dosage. Parenteral opioids including Pethilorfan should remain as an option for treating women in labor pain, particularly when epidural analgesia is not readily available or contraindicated.