Labour analgesia: a randomised, controlled trial comparing intravenous remifentanil and epidural analgesia with ropivacaine and fentanyl

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.

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.

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.

Labor Epidural in a Patient Who is Allergic to Lidocaine: A Case Series

Continuous epidural anesthesia is considered the best modality for pain relief during labor, local anesthetic allergy is an uncommon occurrence but if a patient has an allergy to bupivacaine or lidocaine owing to its cross-reactivity with bupivacaine then it becomes very challenging to manage labor analgesia. A direct challenge test to rule out actual hypersensitivity was not considered a viable option given the risks involved if a severe allergic reaction occurred with the test dose. Using IV opioid-based analgesia has harmful effects for both mother and the baby in addition to decreasing participation of mothers in the birthing process owing to its sedative properties. We report two cases where the mother had a history of lidocaine allergy, so labor analgesia was managed using chloroprocaine patient-controlled epidural analgesia (PCEA).

Mixed-methods systematic review: Childbearing women's views, experiences, and decision-making related to epidural analgesia in labour

AIMS

To investigate childbearing women's views, experiences and decision-making related to epidural analgesia in labour.

DESIGN

Mixed-methods systematic review.

DATA SOURCES

A comprehensive literature search was implemented across Medline, CINAHL and EMBASE from 2000 to September 2018. The literature search was undertaken in January 2018 and updated in September 2018. Thirty papers were selected.

RESULTS

Four overarching synthesized findings were identified: (a) choice; (b) pain management experience; (c) lack of information; and (d) information provision and consent.

REVIEW METHODS

Quality appraisal was conducted using JBI levels of evidence and other established tools. NVivo was used to independently dual code and thematically synthesize qualitative data. A narrative synthesis of the quantitative findings from the included studies was undertaken. The GRADE-CERQual approach was used to assess confidence in the review findings based on the qualitative data. A set of integrated mixed-methods synthesized findings was produced.

CONCLUSION

Recommendations for practice based on the systematic review findings are that midwives should dedicate time to discuss epidural with women and birth partners, ideally during the second or third trimester of pregnancy, asking women what coping strategies or pain relief they have been considering, if any. The factors which may influence the woman's choice of epidural, including pain threshold, ability to cope with pain, timing of epidural and length of labour should be continuously evaluated during labour. The midwife should remain with women after an epidural has been sited, demonstrating understanding of the woman's choice and providing an opportunity for discussion of plans for the remaining labour and birth.

IMPACT

The findings of this systematic review can inform both healthcare professionals and service users on various aspects of the decision-making process about the use of epidural analgesia in labour. Data can be transferable to similar settings in high-income countries.

Duration of labor, delivery mode and maternal and neonatal morbidity after remifentanil patient-controlled analgesia compared with epidural analgesia

OBJECTIVE

The objective of this study was to compare duration of active labor, delivery mode, maternal and neonatal morbidity and women's satisfaction with delivery after intravenous remifentanil patient-controlled analgesia (PCA) or standard epidural analgesia (EDA). Based on clinical observations, we hypothesized that women with PCA would have shorter labor.

STUDY DESIGN

An observational study at a university hospital in Sweden 2009-16. Maternal and neonatal outcomes with PCA (n = 69) and EDA (n = 138) were compared.

RESULTS

Women with PCA had shorter active labor 5.6 ± 3.3 compared to 8.5 ± 4.4 h (p < 0.001) with EDA, and a higher rate of spontaneous delivery 94% (65/69) compared to 65% (n = 90/138) with EDA (p < 0.001). Intrapartum temperature >38 °C (p = 0.001) and signs of fetal asphyxia (p < 0.001) were less common with PCA. No maternal or neonatal sedation was observed. The rates of transient oxygen desaturation <95%, bleeding > 1000 mL and women's satisfaction with delivery did not differ between the groups.

CONCLUSION

PCA had several advantages over EDA, as it was associated with shorter active labor and a higher rate of spontaneous delivery without worsening maternal or neonatal morbidity or women's satisfaction with delivery. Therefore, we suggest an increased availability of PCA for labor analgesia. We recommend continuous one-to-one care and oxygen saturation monitoring for all women during active labor.

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.

Side Effects of Intravenous Patient-Controlled Analgesia with Remifentanil Compared with Intermittent Epidural Bolus for Labour Analgesia - A Randomized Controlled Trial

INTRODUCTION

Epidural analgesia is considered a gold standard in obstetric anaesthesia and analgesia. However, in situation when it is contraindicated, unwanted by the patient or simply unavailable, remifentanil can be an excellent alternative. The goal of our study is to analyse the side effects of intravenous patient-controlled analgesia (IV PCA) with remifentanil compared with epidural analgesia during delivery.

MATERIAL AND METHODS

This study included 155 pregnant women in term for birth, divided into 2 groups: a remifentanil group (RG), and an epidural group (EG). Patients in the RG received intravenous PCA with remifentanil, while patients in the ЕG received epidural analgesia with programmed intermittent bolus dosing. Our primary outcome was maternal safety; the secondary outcome was neonatal safety.

RESULTS

The results present a significantly lower SaO2 value of the parturients in the RG (96.95 ± 1.4 vs 98.22 ± 0.6), and a significantly higher respiratory rate per minute in the EG at all time points after the onset of analgesia (20.85 ± 1.4 vs 18.67 ± 0.9). There was more frequent sedation, nausea and vomiting in the RG, while in the EG there was a more elevated temperature, itching and irregularities in the CTG record. Regarding the newborn, there was no significant difference between the two groups in the Apgar scores, pH, pCO2, pO2, and bicarbonate, while there was a significantly lower value of the base excess in the RG group.

CONCLUSION

PCA with remifentanil is safe for the mother, foetus and the newborn, with minimal side effects. Continuous respiratory monitoring, oxygen supply and following of all consensus recommendations are mandatory.

Patient-controlled analgesia with remifentanil vs. alternative parenteral methods for pain management in labour: a Cochrane systematic review

We aimed to assess the effectiveness of remifentanil used as intravenous patient-controlled analgesia for the pain of labour. We performed a systematic literature search in December 2015 (updated in December 2016). We included randomised, controlled and cluster-randomised trials of women in labour with planned vaginal delivery receiving patient-controlled remifentanil compared principally with other parenteral and patient-controlled opioids, epidural analgesia and continuous remifentanil infusion or placebo. The primary outcomes were patient satisfaction with pain relief and the occurrence of adverse events for mothers and newborns. We assessed risk of bias for each included study and applied the GRADE approach for the quality of evidence. We included total zero event trials, using a constant continuity correction of 0.01 and a random-effect meta-analysis. Twenty studies were included in the qualitative analysis; within these, 3713 participants were randomised and 3569 analysed. Most of our pre-specified outcomes were not studied in the included trials. However, we found evidence that women using patient-controlled remifentanil were more satisfied with pain relief than women receiving parenteral opioids (four trials, 216 patients, very low quality evidence) with a standardised mean difference ([SMD] 95%CI) of 2.11 (0.72-3.49), but were less satisfied than women receiving epidural analgesia (seven trials, 2135 patients, very low quality evidence), -0.22 (-0.40 to -0.04). Data on adverse events were sparse. However, the relative risk (95%CI) for maternal respiratory depression for patient-controlled remifentanil compared with epidural analgesia (three trials, 687 patients, low-quality evidence) was 0.91 (0.51-1.62). Compared with continuous intravenous infusion of remifentanil (two trials, 135 patients, low-quality evidence) no conclusion could be reached as all study arms showed zero events. The relative risk (95%CI) of Apgar scores less than 7 at 5 min after birth compared with epidural analgesia (five trials, 1322 participants, low-quality evidence) was 1.26 (0.62-2.57).

Epidural versus non-epidural or no analgesia for pain management in labour

BACKGROUND

Epidural analgesia is a central nerve block technique achieved by injection of a local anaesthetic close to the nerves that transmit pain, and is widely used as a form of pain relief in labour. However, there are concerns about unintended adverse effects on the mother and infant. This is an update of an existing Cochrane Review (Epidural versus non-epidural or no analgesia in labour), last published in 2011.

OBJECTIVES

To assess the effectiveness and safety of all types of epidural analgesia, including combined-spinal-epidural (CSE) on the mother and the baby, when compared with non-epidural or no pain relief during labour.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register (ClinicalTrials.gov), the WHO International Clinical Trials Registry Platform (ICTRP) (30 April 2017), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials comparing all types of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour. We have not included cluster-randomised or quasi-randomised trials in this update.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risks of bias, extracted data and checked them for accuracy. We assessed selected outcomes using the GRADE approach.

MAIN RESULTS

Fifty-two trials met the inclusion criteria and we have included data from 40 trials, involving over 11,000 women. Four trials included more than two arms. Thirty-four trials compared epidural with opioids, seven compared epidural with no analgesia, one trial compared epidural with acu-stimulation, one trial compared epidural with inhaled analgesia, and one trial compared epidural with continuous midwifery support and other analgesia. Risks of bias varied throughout the included studies; six out of 40 studies were at high or unclear risk of bias for every bias domain, while most studies were at high or unclear risk of detection bias. Quality of the evidence assessed using GRADE ranged from moderate to low quality.Pain intensity as measured using pain scores was lower in women with epidural analgesia when compared to women who received opioids (standardised mean difference -2.64, 95% confidence interval (CI) -4.56 to -0.73; 1133 women; studies = 5; I2 = 98%; low-quality evidence) and a higher proportion were satisfied with their pain relief, reporting it to be "excellent or very good" (average risk ratio (RR) 1.47, 95% CI 1.03 to 2.08; 1911 women; studies = 7; I2 = 97%; low-quality evidence). There was substantial statistical heterogeneity in both these outcomes. There was a substantial decrease in the need for additional pain relief in women receiving epidural analgesia compared with opioid analgesia (average RR 0.10, 95% CI 0.04 to 0.25; 5099 women; studies = 16; I2 = 73%; Tau2 = 1.89; Chi2 = 52.07 (P < 0.00001)). More women in the epidural group experienced assisted vaginal birth (RR 1.44, 95% CI 1.29 to 1.60; 9948 women; studies = 30; low-quality evidence). A post hoc subgroup analysis of trials conducted after 2005 showed that this effect is negated when trials before 2005 are excluded from this analysis (RR 1.19, 95% CI 0.97 to 1.46). There was no difference between caesarean section rates (RR 1.07, 95% CI 0.96 to 1.18; 10,350 women; studies = 33; moderate-quality evidence), and maternal long-term backache (RR 1.00, 95% CI 0.89 to 1.12; 814 women; studies = 2; moderate-quality evidence). There were also no clear differences between groups for the neonatal outcomes, admission to neonatal intensive care unit (RR 1.03, 95% CI 0.95 to 1.12; 4488 babies; studies = 8; moderate-quality evidence) and Apgar score less than seven at five minutes (RR 0.73, 95% CI 0.52 to 1.02; 8752 babies; studies = 22; low-quality evidence). We downgraded the evidence for study design limitations, inconsistency, imprecision in effect estimates, and possible publication bias.Side effects were reported in both epidural and opioid groups. Women with epidural experienced more hypotension, motor blockade, fever, and urinary retention. They also had longer first and second stages of labour, and were more likely to have oxytocin augmentation than the women in the opioid group. Women receiving epidurals had less risk of respiratory depression requiring oxygen, and were less likely to experience nausea and vomiting than women receiving opioids. Babies born to women in the epidural group were less likely to have received naloxone. There was no clear difference between groups for postnatal depression, headache, itching, shivering, or drowsiness. Maternal morbidity and long-term neonatal outcomes were not reported.Epidural analgesia resulted in less reported pain when compared with placebo or no treatment, and with acu-stimulation. Pain intensity was not reported in the trials that compared epidural with inhaled analgesia, or continuous support. Few trials reported on serious maternal side effects.

AUTHORS' CONCLUSIONS

Low-quality evidence shows that epidural analgesia may be more effective in reducing pain during labour and increasing maternal satisfaction with pain relief than non-epidural methods. Although overall there appears to be an increase in assisted vaginal birth when women have epidural analgesia, a post hoc subgroup analysis showed this effect is not seen in recent studies (after 2005), suggesting that modern approaches to epidural analgesia in labour do not affect this outcome. Epidural analgesia had no impact on the risk of caesarean section or long-term backache, and did not appear to have an immediate effect on neonatal status as determined by Apgar scores or in admissions to neonatal intensive care. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia and non-epidural analgesia on women in labour and long-term neonatal outcomes.

Continuous Epidural Analgesia Using an Ester-Linked Local Anesthetic Agent, 2-Chloroprocaine, During Labor: A Case Report

We report the use of the ester-linked local anesthetic, 2-chloroprocaine, for continuous epidural analgesia in a patient in labor with a history of allergic reaction to amide local anesthetics. The patient gave a reliable history of pruritus, hives, erythema, and swelling on her lower extremity after having received a preservative-free amide local anesthetic. This allergy had been confirmed by a dermatologist by her reports. The patient requested an epidural for labor analgesia that was placed successfully. After an initial bolus, a continuous infusion of 1.5% of 2-chloroprocaine was initiated to achieve satisfactory pain relief throughout an uneventful vaginal delivery.

Patient-controlled analgesia with remifentanil versus alternative parenteral methods for pain management in labour

BACKGROUND

Multiple analgesic strategies for pain relief during labour are available. Recently remifentanil, a short-acting opioid, has recently been used as an alternative analgesic due to its unique pharmacological properties.

OBJECTIVES

To systematically assess the effectiveness of remifentanil intravenous patient-controlled analgesia (PCA) for labour pain, along with any potential harms to the mother and the newborn.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (9 December 2015), ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP), handsearched congress abstracts (November 2015), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and cluster-randomised trials comparing remifentanil (PCA) with another opioid (intravenous (IV)/intramuscular (IM)), or with another opioid (PCA), or with epidural analgesia, or with remifentanil (continuous IV), or with remifentanil (PCA, different regimen), or with inhalational analgesia, or with placebo/no treatment in all women in labour including high-risk groups with planned vaginal delivery.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion, extracted data, and appraised study quality.We contacted study authors for additional information other than incomplete outcome data. We performed random-effects meta-analysis.To reduce the risk of random error in meta-analysis we performed trial sequential analysis. We included total zero event trials and used a constant continuity correction of 0.01 (ccc 0.01) for meta-analysis. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) approach to assess the quality of evidence.

MAIN RESULTS

Twenty RCTs with 3569 women were included. Of those, 10 trials (2983 participants) compared remifentanil (PCA) to an epidural, four trials (216 participants) to another opioid (IV/IM), three trials (215 participants) to another opioid (PCA), two trials (135 participants) to remifentanil (continuous IV), and one trial (20 participants) to remifentanil (PCA, different regimen). No trials were identified for the remaining comparisons.Methodological quality of studies was moderate to poor. We assessed risk of bias as high for blinding issues and incomplete outcome data in 65% and 45% of the included studies, respectively.There is evidence of effect that women in the remifentanil (PCA) group were more satisfied with pain relief than women in the other opioids (IV/IM) group (standardised mean difference (SMD) 2.11, 95% confidence interval (CI) 0.72 to 3.49, four trials, very low-quality evidence), and that women were less satisfied compared to women in the epidural group (SMD -0.22, 95% CI -0.40 to -0.04, seven trials, very low-quality evidence).There is evidence of effect that remifentanil (PCA) provided stronger pain relief at one hour than other opioids administered IV/IM (SMD -1.58, 95% CI -2.69 to -0.48, three trials, very low-quality evidence) or via PCA (SMD -0.51, 95% CI -1.01 to -0.00, three trials, very low-quality evidence). Pain intensity was higher in the remifentanil (PCA) group compared to the epidural group (SMD 0.57, 95% CI 0.31 to 0.84, six trials, low-quality evidence).Data were limited on safety aspects for both the women and the newborns. Only one study analysed maternal apnoea in a comparison of remifentanil (PCA) versus epidural and reported that half of the women in the remifentanil and none in the epidural group had an apnoea (very low-quality evidence). There is no evidence of effect that remifentanil (PCA) was associated with an increased risk for maternal respiratory depression when compared to epidural analgesia (RR 0.91, 95% CI 0.51 to 1.62, ccc 0.01, three trials, low-quality evidence) and no reliable conclusion might be reached compared to remifentanil (continuous IV) (all study arms included zero events, two trials, low-quality evidence). In one trial of remifentanil (PCA) versus another opioid (IM) three out of 18 women in the remifentanil and none out of 18 in the control group had a respiratory depression (very low-quality evidence).There is no evidence of effect that remifentanil (PCA) was associated with an increased risk for newborns with Apgar scores less than seven at five minutes compared to epidural analgesia (RR 1.26, 95% CI 0.62 to 2.57, ccc 0.01, five trials, low-quality evidence) and no reliable conclusion might be reached compared to another opioid (IV) and compared to remifentanil (PCA, different regimen) both with zero events in all study arms (one trial, very-low quality evidence). In one trial of remifentanil (PCA) versus another opioid (PCA) none out of nine newborns in the remifentanil and three out of eight in the opioid (PCA) group had Apgar scores less than seven (very-low quality evidence).There is evidence that remifentanil (PCA) was associated with a lower risk for the requirement of additional analgesia when compared to other opioids (IV/IM) (RR 0.57, 95% CI 0.40 to 0.81, three trials, moderate-quality evidence) and that it was associated with a higher risk compared to epidural analgesia (RR 9.27, 95% CI 3.73 to 23.03, ccc 0.01, six trials, moderate-quality evidence). There is no evidence of effect that remifentanil (PCA) reduced the requirement for additional analgesia compared to other opioids (PCA) (RR 0.76, 95% CI 0.45 to 1.28, three trials, low-quality evidence).There is evidence that there was no difference in the risk for caesarean delivery between remifentanil (PCA) and other opioids (IV/IM) (RR 0.63, 95% CI 0.30 to 1.32, ccc 0.01, four trials, low-quality evidence) and epidural analgesia (RR 1.0, 95% CI 0.82 to 1.22, ccc 0.01, nine trials, moderate-quality evidence), respectively. Pooled meta-analysis revealed an increased risk for caesarean section under remifentanil (PCA) compared to other opioids (PCA) (RR 2.78, 95% CI 0.99 to 7.82, two trials, very low-quality evidence). However, a wide range of clinically relevant and non-relevant treatment effects is compatible with this result.

AUTHORS' CONCLUSIONS

Based on the current systematic review, there is mostly low-quality evidence to inform practice and future research may significantly alter the current situation. The quality of evidence is mainly limited by poor quality of the studies, inconsistency, and imprecision. More research is needed on maternal and neonatal safety outcomes (maternal apnoea and respiratory depression, Apgar score) and on the optimal mode and regimen of remifentanil administration to provide highest efficacy with reasonable adverse effects for mothers and their newborns.

Combination of dexmedetomidine and remifentanil for labor analgesia: A double-blinded, randomized, controlled study

BACKGROUND

Satisfactory analgesia is of great importance in the labor. The clinical efficacy and side effects of remifentanil in the management of labor pain had been evaluated. Dexmedetomidine (DMET) demonstrates an antinociceptive effect in visceral pain conditions. Aims of the study were to assess whether the combination of DMET with remifentanil would produce a synergistic effect that results in lower analgesic requirements. Furthermore, whether this combination would have less maternal and neonatal adverse effects.

PATIENTS AND METHODS

Sixty American Society of Anesthesiologists physical status I-II pregnant women had been enrolled into this study. All were full term (37-40 weeks' gestation), singleton fetus with cephalic presentation in the first stage of spontaneous labor. They were divided into two groups group (I) Patient-controlled IV remifentanil analgesia (bolus dose 0.25 μg/kg, lockout interval 2 min) increased by 0.25 μg/kg to a maximum bolus dose 1 μg/kg in addition to a loading dose of DMET 1 μg/kg over 20 min, followed by infusion at 0.5 μg/kg/h group (II) Patient-controlled IV remifentanil analgesia (PCA) (bolus dose 0.25 μg/kg, lockout interval 2 min) increased by 0.25 μg/kg to a maximum bolus dose 1 μg/kg in addition to a the same volume of normal saline as a loading dose, followed by a continuous saline infusion. Visual analog scale score, maternal, and fetal complications and patients' satisfaction were recorded.

RESULTS

Patients receiving a combination of PCA remifentanil and DMET had a lower pain score compared with remifentanil alone in the second stage of labor (P = 0.001). The Total consumption of remifentanil was reduced by 53.3% in group I. There was an increased incidence of maternal complications and a lower patient satisfaction score in group II.

CONCLUSION

DMET has an opioid sparing effect; a combination of DMET and remifentanil produces a synergistic effect that results in lower analgesic requirements and less maternal and neonatal adverse events.

Effect-site concentration of remifentanil during patient-controlled analgesia in labour

BACKGROUND

Intravenous remifentanil has been described for patient-controlled analgesia in labour. Recently, the application of target-controlled infusion pumps with Minto's pharmacokinetic/pharmacodynamic model has been reported. Hypothetical effect-site remifentanil concentration during patient-controlled analgesia for labour has yet to be examined. The aim of this concept study was to explore characteristics of this parameter.

METHODS

We performed a historical cohort study based on our previous randomised cross-over clinical trial and analysed hypothetical effect-site remifentanil concentration. Values at spontaneous vaginal delivery and Apgar scores were tested for correlation. The association between pain score and the corresponding effect-site remifentanil concentration before and after bolus administration, and their relative difference, was examined with a linear mixed-effects model, adjusted for other variables.

RESULTS

A series of 23 parturients with uncomplicated singleton pregnancies were included. On average, effect-site remifentanil concentration was highest during the third quarter throughout our recordings (5.5ng/mL; maximum 15.8ng/mL). The mean (median) {IQR} [range] at spontaneous vaginal delivery (n=14) was 2.52 (1.32) {0.95-4.28} [0.65-6.88] ng/mL, all Apgar scores were >7, and no correlation was confirmed. A negative association between effect-site remifentanil concentration before bolus administration and pain score (scale 0-100) was observed (-3.9, 95% CI -5.16 to -2.61, P <0.01).

CONCLUSIONS

The residual value of hypothetical effect-site remifentanil concentration before uterine contraction, at the beginning of bolus administration, predicted lower pain scores. Monitoring effect-site remifentanil concentration may be potentially useful when remifentanil is administered for labour analgesia. However, our results need to be confirmed with a pharmacokinetic model optimized for pregnant patients.

Intravenous remifentanil versus epidural ropivacaine with sufentanil for labour analgesia: a retrospective study

Remifentanil with appropriate pharmacological properties seems to be an ideal alternative to epidural analgesia during labour. A retrospective cohort study was undertaken to assess the efficacy and safety of remifentanil intravenous patient-controlled analgesia (IVPCA) compared with epidural analgesia. Medical records of 370 primiparas who received remifentanil IVPCA or epidural analgesia were reviewed. Pain and sedation scores, overall satisfaction, the extent of pain control, maternal side effects and neonatal outcome as primary observational indicators were collected. There was a significant decline of pain scores in both groups. Pain reduction was greater in the epidural group throughout the whole study period (0∼180 min) (P<0.0001), and pain scores in the remifentanil group showed an increasing trend one hour later. The remifentanil group had a lower SpO₂ (P<0.0001) and a higher sedation score (P<0.0001) within 30 min after treatment. The epidural group had a higher overall satisfaction score (3.8±0.4 vs. 3.7±0.6, P = 0.007) and pain relief score (2.9±0.3 vs. 2.8±0.4, P<0.0001) compared with the remifentanil group. There was no significant difference on side effects between the two groups, except that a higher rate of dizziness (1% vs. 21.8%, P<0.0001) was observed during remifentanil analgesia. And logistic regression analysis demonstrated that nausea, vomiting were associated with oxytocin usage and instrumental delivery, and dizziness was associated to the type and duration of analgesia. Neonatal outcomes such as Apgar scores and umbilical-cord blood gas analysis were within the normal range, but umbilical pH and base excess of neonatus in the remifentanil group were significantly lower. Remifentanil IVPCA provides poorer efficacy on labor analgesia than epidural analgesia, with more sedation on parturients and a trend of newborn acidosis. Despite these adverse effects, remifentanil IVPCA can still be an alternative option for labor analgesia under the condition of one-to-one bedside care, continuous monitoring, oxygen supply and preparation for neonatal resuscitation.

A comparison of remifentanil parturient-controlled intravenous analgesia with epidural analgesia: a meta-analysis of randomized controlled trials

BACKGROUND

Epidural analgesia is generally accepted as the most effective form of pain relief during labor. Remifentanil patient-controlled IV analgesia (PCIA), which is less invasive than epidural analgesia, may be an attractive alternative. In this meta-analysis, we compared the efficacy and safety of the 2 analgesic techniques for labor pain.

METHODS

Databases of PubMed, EMBASE, and Cochrane Library were searched independently by 2 reviewers to retrieve eligible randomized controlled clinical trials. The primary end points were pain scores at 1 and 2 hours, and the secondary end points were nausea, vomiting, pruritus, and umbilical artery pH values. Mean difference (MD) or risk ratio with 95% confidence intervals (CIs) were calculated for each end point. GRADE profiler was applied to assess the quality of evidence.

RESULTS

Five eligible trials were retrieved and analyzed. We found that parturients with remifentanil PCIA had higher visual analog scale (10-cm scale) pain scores than those who received epidural analgesia at 1 hour (MD = 1.9 cm; 95% CI, 0.5-3.3; I = 94%) and 2 hours (MD = 3.0 cm; 95% CI, 0.7-5.2; I = 89%) after initiation of analgesia. There was no statistical difference between epidural analgesia and remifentanil PCIA in the incidence of nausea, vomiting, pruritus, or umbilical artery pH values. However, the CIs are quite wide and contain clinically significant differences. According to GRADE profiler, most end points had moderate quality except that pain scores at 1 hour were of low quality.

CONCLUSIONS

This meta-analysis suggests that remifentanil PCIA is not superior to epidural analgesia in analgesic efficacy during labor. Given the wide CIs of the pooled results for secondary maternal and neonatal outcomes, definite conclusions cannot be drawn for those outcomes. Further studies are still warranted to validate these conclusions.

Analgesia for childbirth: modern insights into an age-old challenge and the quest for an ideal approach

SUMMARY It is widely recognized that childbirth may be the most painful experience in a woman’s lifetime and that women have a right to relief. There are many options, but the efficacy of only a few is supported by robust evidence. Many influences determine which method of pain relief is chosen, including social and cultural factors, availability, cost and personal preference. Due to human diversity and the differing perspectives of consumers, obstetric care providers and health administrators, there is no such thing as ‘an ideal approach’. In resource-rich societies, major advances in parturient safety and outcome flow from technique development and better monitoring. Greater awareness of the negative impact of untreated pain and of the relevance of genetic, cultural and social factors motivates research into better predictive models, novel therapies and optimization of existing methods.

Must we press on until a young mother dies? Remifentanil patient controlled analgesia in labour may not be suited as a "poor man's epidural"

BACKGROUND

The epidural route is still considered the gold standard for labour analgesia, although it is not without serious consequences when incorrect placement goes unrecognized, e.g. in case of intravascular, intrathecal and subdural placements. Until now there has not been a viable alternative to epidural analgesia especially in view of the neonatal outcome and the need for respiratory support when long-acting opioids are used via the parenteral route. Pethidine and meptazinol are far from ideal having been described as providing rather sedation than analgesia, affecting the cardiotocograph (CTG), causing fetal acidosis and having active metabolites with prolonged half-lives especially in the neonate. Despite these obvious shortcomings, intramuscular and intravenously administered pethidine and comparable substances are still frequently used in delivery units. Since the end of the 90 ths remifentanil administered in a patient-controlled mode (PCA) had been reported as a useful alternative for labour analgesia in those women who either don't want, can't have or don't need epidural analgesia.

DISCUSSION

In view of the need for conversion to central neuraxial blocks and the analgesic effect remifentanil has been demonstrated to be superior to pethidine. Despite being less effective in terms of the resulting pain scores, clinical studies suggest that the satisfaction with analgesia may be comparable to that obtained with epidural analgesia. Owing to this fact, remifentanil has gained a place in modern labour analgesia in many institutions. However, the fact that remifentanil may cause harm should not be forgotten when the use of this potent mu-agonist is considered for the use in labouring women. In the setting of one-to-one midwifery care, appropriate monitoring and providing that enough experience exists with this potent opioid and the treatment of potential complications, remifentanil PCA is a useful option in addition to epidural analgesia and other central neuraxial blocks. Already described serious consequences should remind us not refer to remifentanil PCA as a "poor man's epidural" and to safely administer remifentanil with an appropriate indication.

SUMMARY

Therefore, the authors conclude that economic considerations and potential cost-savings in conjunction with remifentanil PCA may not be appropriate main endpoints when studying this valuable method for labour analgesia.

Remifentanil target-controlled infusion during second stage labour in high-risk parturients: a case series

BACKGROUND

Providing adequate analgesia and appropriate sedation to high-risk parturients during late second stage labour without compromising foetal safety remains a major challenge, especially in situations when neuraxial block is not applicable. Remifentanil emerged as an option for labour analgesia during the last decade but may be suitable for the facilitation of complicated vaginal deliveries as well.

METHODS

A retrospective chart review of nine labouring women with significant medical and/or obstetrical risk factors was conducted. According to the assessment of an experienced obstetrician, vaginal delivery could only be achieved with profound analgesia, and neuraxial block was not possible because of contraindications, technical failure, or shortage of time. Mode of delivery, need for neonatal resuscitation, maternal and neonatal vital parameters, drug consumption, and personnel resource expenses were recorded.

RESULTS

Remifentanil target-controlled infusion (TCI) facilitated vaginal delivery in eight out of nine women. No serious adverse events were observed, but three newborns needed initial respiratory support for a few minutes. The total cost of remifentanil TCI administration to facilitate vaginal delivery compared with the estimated additional cost of an emergency caesarean section was negligible.

CONCLUSION

This case series suggests that remifentanil TCI may be used to facilitate vaginal delivery in high-risk parturients when other forms of analgesia are limited. However, the small number of patients studied does not allow generalisation of the results; neither can safety concerns be dispelled yet.

Efficacy and safety of remifentanil as an alternative labor analgesic

The objective of this review was to evaluate the clinical efficacy and safety of remifentanil in the management of labor pain. Although neuraxial analgesia is the best option during labor, alternative analgesic options are needed for patients with contraindications. Using a systematic literature search, clinical outcomes of remifentanil for labor pain have been summarized. Also, comparisons of remifentanil to other options including meperidine, epidural analgesia, fentanyl, and nitrous oxide are provided. Based on the literature review, remifentanil is associated with high overall maternal satisfaction and favorable side-effect profile. However, due to the low reporting of adverse events, large, randomized controlled trials are needed to evaluate maternal and neonatal safety adequately and determine the optimal dosing needed to provide effective analgesia. While remifentanil is a feasible alternative for patients who cannot or do not want to receive epidural analgesia, administration should be monitored closely for potential adverse effects.

Efficacy and side effects of intravenous remifentanil patient-controlled analgesia used in a stepwise approach for labour: an observational study

BACKGROUND

Remifentanil has a suitable pharmacological profile for labour analgesia. In this prospective, observational study, intravenous patient-controlled analgesia with remifentanil, using stepwise bolus doses without background infusion, was examined during the first and second stages of labour. Outcomes were pain reduction, maternal satisfaction, maternal and neonatal side effects and remifentanil metabolism in the neonate.

METHODS

Parturients with normal term singleton pregnancies were recruited. The initial remifentanil bolus dose was 0.15 μg/kg, increasing in steps of 0.15 μg/kg, with a 2-min lock-out. Pain scores using a 100 mm visual analogue scale, systolic and diastolic blood pressures, respiratory rate and maternal sedation were recorded every 15 min. Maternal oxygen saturation and heart rate were monitored continuously. Neonatal data included Apgar scores, clinical examination, naloxone use, resuscitation, umbilical cord blood gases and remifentanil concentrations.

RESULTS

Forty-one parturients were enrolled. Pain scores were significantly reduced in the first 3 h of patient-controlled analgesia use compared to baseline, and at the end of the first and second stages of labour (P<0.05). Maximal pain reduction was 60% (P<0.01). One patient had inadequate pain relief and converted to epidural analgesia. The mean highest dose of remifentanil was 0.7 μg/kg [range 0.3-1.05]. Ninety-three percent of patients were satisfied with their analgesia. The lowest oxygen saturation was 91% and the lowest respiratory rate was 9 breaths/min. Eleven parturients (27%) received supplemental oxygen due to oxygen saturations <92%. Maternal sedation was moderate, and neonatal data reassuring.

CONCLUSIONS

Remifentanil intravenous patient-controlled analgesia provides adequate pain relief and high maternal satisfaction during the first and second stages of labour. Maternal sedation and respiratory depression may occur, but no serious neonatal side effects were recorded. Careful monitoring is mandatory.