Labour pain with remifentanil patient-controlled analgesia versus epidural analgesia: a randomised equivalence trial

Effects of epidural analgesia on intrapartum maternal fever and maternal outcomes: an updated systematic review and meta-analysis

OBJECTIVE

Epidural-related maternal fever in women is a common clinical phenomenon that leads to adverse consequences for mothers and neonates. The meta-analysis aimed to quantify the risk for intrapartum maternal fever after epidural analgesia (EA) stratified according to parity. The secondary objective was to investigate the association between EA and maternal outcomes.

METHODS

An electronic literature search of the Medline/PubMed, Embase, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure databases was performed to identify studies reporting the occurrence of intrapartum fever in parturients. Studies were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and meta-analysis was performed using Review Manager version 5.3.

RESULTS

Seventeen randomized controlled trials (RCTs) (5959 parturients) were included. Odds ratios for maternal fever in the analysis were 4.17 (95% confidence interval (CI) 2.93-5.94) and 5.83 (95% CI 4.96-6.87), respectively. Results of subgroup analysis according to parity were consistent. EA significantly prolonged the length of the first stage of labor (MD 34.52 [95% CI 12.13-56.91]) and the second stage of labor (MD 9.10 [95% CI 4.51-13.68]). Parturients who received EA were more likely to undergo instrumental delivery (OR 2.03 [95% CI 1.44-2.86]) and oxytocin augmentation (OR 1.45 [95% CI 1.12-1.88]). There were no differences in cesarean delivery rates between the EA and non-EA groups.

CONCLUSIONS

Parturients who received EA exhibited a higher incidence of intrapartum fever. Credibility of the subgroup analyses was low because the mixed group did not effectively represent multiparas.

Median effective dose of spinal ropivacaine in combined spinal and epidural anesthesia for emergency cesarean delivery following failed vaginal delivery with epidural labor analgesia: a single-blind, sequential dose-finding study

PURPOSE

This study aimed to estimate the median effective dose of intrathecal isobaric ropivacaine without opioid required for adequate cesarean delivery anesthesia after epidural labor analgesia.

METHODS

Patients aged 20-40 years with American Society of Anesthesiology scores of I-II, body mass index ≤ 36, who underwent emergency cesarean delivery after failed vaginal delivery with epidural analgesia of a duration ≤ 6 h were included in the study. After removal of the epidural used for labor analgesia, a new combined spinal epidural was performed, and a dose of intrathecal isobaric ropivacaine without opioid was administered. The dose was determined using up-down methodology, with the starting patient's dose set to 12 mg. Adequate anesthesia, defined as a pinprick level no lower than T6 at 5 min after ropivacaine administration, resulted in the next patient receiving a dose of ropivacaine 1 mg higher, and inadequate anesthesia 1 mg lower. The primary outcome was the median (95% confidence interval (CI)) dose of spinal ropivacaine required for adequate cesarean delivery anesthesia.

RESULTS

Of the 46 patients included in the study, 40 were analyzed. The median spinal ropivacaine dose was 8.11 mg (95% CI 7.29-8.93 mg) by the Dixon and Mood method and 8.06 mg (95% CI 6.93-9.00 mg) by isotonic regression. Two patients had high spinal anesthesia.

CONCLUSION

Our findings suggest that for 50% of patients undergoing cesarean delivery after failed vaginal delivery with epidural analgesia, an 8-mg spinal dose of isobaric ropivacaine without opioid provides an anesthesia level no lower than T6 at 5 min.

Epidural-related maternal fever: incidence, pathophysiology, outcomes, and management

Epidural-related maternal fever affects 15% to 25% of patients who receive a labor epidural. Two meta-analyses demonstrated that epidural-related maternal fever is a clinical phenomenon, which is unlikely to be caused by selection bias. All commonly used neuraxial techniques, local anesthetics with or without opioids, and maintenance regimens are associated with epidural-related maternal fever, however, the impact of each component is unknown. Two major theories surrounding epidural-related maternal fever development have been proposed. First, labor epidural analgesia may lead to the development of hyperthermia through a sterile (noninfectious) inflammatory process. This process may involve reduced activation of caspase-1 (a protease involved in cell apoptosis and activation of proinflammatory pathways) secondary to bupivacaine, which impairs the release of the antipyrogenic cytokine, interleukin-1-receptor antagonist, from circulating leucocytes. Detailed mechanistic processes of epidural-related maternal fever remain to be determined. Second, thermoregulatory mechanisms secondary to neuraxial blockade have been proposed, which may also contribute to epidural-related maternal fever development. Currently, there is no prophylactic strategy that can safely prevent epidural-related maternal fever from occurring nor can it easily be distinguished clinically from other causes of intrapartum fever, such as chorioamnionitis. Because intrapartum fever (of any etiology) is associated with adverse outcomes for both the mother and baby, it is important that all parturients who develop intrapartum fever are investigated and treated appropriately, irrespective of labor epidural utilization. Institution of treatment with appropriate antimicrobial therapy is recommended if an infectious cause of fever is suspected. There is currently insufficient evidence to warrant a change in recommendations regarding provision of labor epidural analgesia and the benefits of good quality labor analgesia must continue to be reiterated to expectant mothers.

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.

Delivery mode and neonatal morbidity after remifentanil-PCA or epidural analgesia using the Ten Groups Classification System: A 5-year single-centre analysis of more than 10 000 deliveries

OBJECTIVE

This study aimed to explore the potential association between remifentanil patient-controlled analgesia (RPCA) or epidural analgesia (EA), and caesarean section (CS) rate, operative vaginal delivery rate (OVD), operative delivery (OD) rate (CS or OVD) with pathological cardiotocography (CTG) tracing, Apgar score < 7 at 5 min after birth, incidence of perinatal asphyxia and neonatal intensive care unit (NICU) admission within four groups of the Ten Groups Classification System (TGCS) labour types; group 1: nulliparous, singleton cephalic, ≥37 weeks, spontaneous onset of labour; group 2a: nulliparous, singleton cephalic, ≥37 weeks, induction of labour; group 3: multiparous, singleton cephalic, ≥37 weeks, spontaneous onset of labour; group 4a: multipara, singleton cephalic, ≥37 weeks, induction of labour). We hypothesized that labour and delivery outcomes between RPCA and EA would differ within the different TGCS labour types.

STUDY DESIGN

10,561 deliveries (4876 with RPCA, 5685 with EA) at the University Clinical Centre Ljubljana, Slovenia, from 2015 through 2019 were analysed using the Slovenian National Perinatal Information System data.

RESULTS

Compared to EA, RPCA was associated with lower CS and OVD rates in nulliparous women with spontaneous onset of labour (group 1) (CS: 9.9 % vs14.3 %; P < 0.001) (OVD: 5.1 % vs 8.4 %; P < 0.001), in nulliparous women with induced labour (group 2a) (CS: 14.8 % vs 24.2 %; P < 0.001) (OVD: 6.5 % vs 8.9 %; P = 0.036) and in multiparous women with spontaneous onset of labour (group 3) (CS: 1.1 % vs 2.4 %; P = 0.021) (OVD: 0.1 % vs 0.8 %; P = 0.007), respectively. RPCA was associated with a lower incidence of OD with pathologic CTG in all four studied groups (groups 1, 2a, 3, 4a). No differences in APGAR < 7 at 5 min, neonatal asphyxia, and NICU admission were recorded between the two analgesic techniques within any of the TGCS groups.

CONCLUSION

Compared to EA, RPCA was not associated with worse delivery and neonatal outcomes within any of the four studied TGCS groups. RPCA could be used for labour analgesia routinely if strict adherence to protocols is ensured and regular staff training is provided.

Interventions for the prevention or treatment of epidural-related maternal fever: a systematic review and meta-analysis

Background

Epidural-related maternal fever in women in labour has consequences for the mother and neonate. There has been no systematic review of preventive strategies.

Methods

RCTs evaluating methods of preventing or treating epidural-related maternal fever in women in active labour were eligible. We searched MEDLINE, EMBASE, CINAHL, Web of Science, CENTRAL, and grey literature sources were searched from inception to April 2021. Two review authors independently undertook study selection. Data extraction and quality assessment was performed by a single author and checked by a second. The Cochrane Risk of Bias 2 tool was used. Meta-analyses for the primary outcome, incidence of intrapartum fever, were performed using the DerSimonian and Laird random effects model to produce summary risk ratios (RRs) with 95% confidence intervals (95% CIs).

Results

Forty-two records, representing 34 studies, were included. Methods of reduced dose epidural reduced the incidence of intrapartum fever, but this was not statistically significant when six trials at high risk of bias were removed (seven trials; 857 participants; RR=0.83; 95% CI, 0.41–1.67). Alternative methods of analgesia and high-dose prophylactic systemic steroids reduced the risk of intrapartum fever compared with epidural analgesia. Prophylactic paracetamol was not effective.

Conclusions

There is no clear evidence to support the use of any individual preventative or therapeutic intervention for epidural-related maternal fever. Further research should focus on understanding the mechanism of fever development to enable RCTs of potential interventions to reduce the incidence of intrapartum fever development and the subsequent disease burden felt by the neonate.

Clinical trial registration

CRD42021246929.

Neuraxial administration of morphine combined with lidocaine induces regional antinociception in inland bearded dragons (Pogona vitticeps)

OBJECTIVE

To assess the antinociceptive efficacy and safety of neuraxial morphine in inland bearded dragons (Pogona vitticeps).

ANIMALS

10 healthy adult bearded dragons.

PROCEDURES

Animals were sedated with alfaxalone (15 mg/kg) SC prior to neuraxial injections. In a randomized, blinded, placebo-controlled, crossover design, animals received preservative-free morphine (0.5 mg/kg) combined with lidocaine (2 mg/kg) or lidocaine (2 mg/kg) only (control treatment). For both treatments, saline (0.9% NaCl) solution was used for dilution to a total volume of 0.3 mL/kg. If the initial injection did not result in motor block of the pelvic limbs or cloaca relaxation within 10 minutes, a second injection was performed. Measurements consisted of bilateral mechanical stimulation of the limbs and at 25%, 50%, and 75% of the trunk's length as well as cloacal tone to assess spread and duration of motor block. Pelvic limb withdrawal latencies in response to a thermal noxious stimulus were measured over a 48-hour period to assess antinociception.

RESULTS

Success rate following the first injection was 90% (18/20 injections) and increased to 100% following a second injection. Motor block occurred within 5 minutes with both treatments. Pelvic limb withdrawal latencies were significantly prolonged following neuraxial morphine versus control treatment for at least 12 hours after injection. By 24 hours, no effect of morphine on pelvic limb latencies was detectable.

CLINICAL RELEVANCE

These results demonstrated that neuraxial administration of morphine results in regional antinociceptive effects for at least 12 hours and has no clinically relevant adverse effects in healthy bearded dragons. This technique has potential for providing regional analgesia in this species.

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).

Epidural analgesia, intrapartum hyperthermia, and neonatal brain injury: a systematic review and meta-analysis

BACKGROUND

Epidural analgesia is associated with intrapartum hyperthermia, and chorioamnionitis is associated with neonatal brain injury. However, it is not known if epidural hyperthermia is associated with neonatal brain injury. This systematic review and meta-analysis investigated three questions: (1) does epidural analgesia cause intrapartum hyperthermia, (2) is intrapartum hyperthermia associated with neonatal brain injury, and (3) is epidural-induced hyperthermia associated with neonatal brain injury?

METHODS

PubMed, ISI Web of Knowledge, The Cochrane Library, and Embase were searched from inception to January 2020 using Medical Subject Headings (MeSH) terms relating to epidural analgesia, hyperthermia, labour, and neonatal brain injury. Studies were reviewed independently for inclusion and quality by two authors (Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach). Two meta-analyses were performed using the Mantel-Haenszel fixed effect method to generate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Forty-one studies were included for Question 1 (646 296 participants), 36 for Question 2 (11 866 021 participants), and two studies for Question 3 (297 113 participants). When the mode of analgesia was randomised, epidural analgesia was associated with intrapartum hyperthermia (OR: 4.21; 95% CI: 3.48-5.09). There was an association between intrapartum hyperthermia and neonatal brain injury (OR: 2.79; 95% CI: 2.54-2.3.06). It was not possible to quantify the association between epidural-induced hyperthermia and neonatal brain injury.

CONCLUSIONS

Epidural analgesia is a cause of intrapartum hyperthermia, and intrapartum hyperthermia of any cause is associated with neonatal brain injury. Further work is required to establish if epidural-induced hyperthermia is a cause of neonatal brain injury.

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.

Epidural-Related Fever and Maternal and Neonatal Morbidity: A Systematic Review and Meta-Analysis

BACKGROUND

While epidural analgesia (EA) is associated with maternal fever during labor, the impact on the risk for maternal and/or neonatal sepsis is unknown.

OBJECTIVES

The aim of this systematic review was to investigate the effect of epidural-related intrapartum fever on maternal and neonatal outcomes.

METHODS

OVID MEDLINE, OVID Embase, the Cochrane Library, Cochrane Controlled Register of Trials, and clinical trial registries were searched for randomized controlled trials (RCT) and observational cohort studies from inception to November 2018. A total of 761 studies were identified with 100 eligible for full-text review. Only articles investigating the relationship between EA and maternal fever during labor were eligible for inclusion. Study quality was assessed using the Cochrane's Risk of Bias tool and National Institute of Health Quality Assessment Tool. Two meta-analyses - one each for the RCT and observational cohort groups - were performed using the random-effects model of Mantel-Haenszel to produce summary risk ratios (RR) with 95% CI.

RESULTS

Twelve RCTs and 16 observational cohort studies involving 579,157 parturients were included. RRs for maternal fever for the RCT and cohort analyses were 3.54 (95% CI 2.61-4.81) and 5.60 (95% CI 4.50-6.97), respectively. Meta-analyses of RR for maternal infection in both groups were infeasible given few occurrences. Meta-analysis of data from observational studies showed an increased risk for maternal antibiotic treatment in the epidural group (RR 2.60; 95% CI 1.31-5.17). For both analyses, neonates born to women with an epidural were not evaluated more often for suspected sepsis. Neither analysis reported an increased rate of neonatal bacteremia or neonatal antibiotic treatment after EA, although data precluded conclusiveness.

CONCLUSION

EA increases the risk of intrapartum fever and maternal antibiotic treatment. However, a definite conclusion on whether EA increases the risk for a proven maternal and/or neonatal bacteremia cannot be drawn due to the low quality of data. Further research on whether epidural-related intrapartum fever is of infectious origin or not is therefore needed.

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.

Beneficial Effects of Remifentanil Against Excitotoxic Brain Damage in Newborn Mice

Background: Remifentanil, a synthetic opioid used for analgesia during cesarean sections, has been shown in ex vivo experiments to exert anti-apoptotic activity on immature mice brains. The present study aimed to characterize the impact of remifentanil on brain lesions using an in vivo model of excitotoxic neonatal brain injury. Methods: Postnatal day 2 (P2) mice received three intraperitoneal injections of remifentanil (500 ng/g over a 10-min period) or saline just before an intracortical injection of ibotenate (10 μg). Cerebral reactive oxygen species (ROS) production, cell death, in situ labeling of cortical caspase activity, astrogliosis, inflammation mediators, and lesion size were determined at various time points after ibotenate injection. Finally, behavioral tests were performed until P18. Results: In the injured neonatal brain, remifentanil significantly decreased ROS production, cortical caspase activity, DNA fragmentation, interleukin-1β levels, and reactive astrogliosis. At P7, the sizes of the ibotenate-induced lesions were significantly reduced by remifentanil treatment. Performance on negative geotaxis (P6-8) and grasping reflex (P10-12) tests was improved in the remifentanil group. At P18, a sex specificity was noticed; remifentanil-treated females spent more time in the open field center than did the controls, suggesting less anxiety in young female mice. Conclusions: In vivo exposure to remifentanil exerts a beneficial effect against excitotoxicity on the developing mouse brain, which is associated with a reduction in the size of ibotenate-induced brain lesion as well as prevention of some behavioral deficits in young mice. The long-term effect of neonatal exposure to remifentanil should be investigated.

Application of remifentanil combined with propofol in the diagnosis of colon cancer with awakening painless digestive endoscopy

Anesthetic effect of remifentanil combined with propofol in awakening painless endoscopy was analyzed. Retrospective analysis of 120 cases of colon cancer were treated in Dongying People's Hospital from June 2015 to December 2017. All of them were treated by awakening painless digestive endoscopy, divided into 60 cases in observation group (combined with remifentanil and propofol anesthesia), and 60 cases in control group (combined intravenous anesthesia of finanib and propofol). The data were respectively recorded at time-points of oxygen inhalation, intubation for 10 min, awakening time, waking time, and the time-points for each represented as the time-points of T1, T2, T3, T4, T5 and recorded the diastolic blood pressure (DBP), respiratory rate (RR) and heart rate (HR), and compared the awakening effect and the occurrence of adverse reaction. There was no significant difference in the DBP index between the two groups at time-point T1 (P>0.05). The time-points of T2, T3, T4 and T5 were significantly different from the observation group (P<0.05). There was no significant difference in RR index between the two groups and between the same groups (P>0.05). Compared with the control group, the awakening time and consciousness recovering of the observation group is lower (P<0.05). The incidence of adverse reactions after awakening operation between the two groups was statistically significant (P<0.05). The local pain rate in the observation group after the awakening operation was lower than the control group. The combined use of trace remifentanil and small dose propofol in the awakening painless digestive endoscopy can make the patients with colon cancer more stable when they are in the awakening state, so as to improve the safety of awakening painless digestive endoscopy. It is worth promoting in clinical practice.

Pharmacological pain relief and fear of childbirth in low risk women; secondary analysis of the RAVEL study

BACKGROUND

Fear of childbirth may reduce the womens' pain tolerance during labour and may have impact on the mother-infant interaction. We aimed to assess (1) the association between fear of childbirth antepartum and subsequent request for pharmacological pain relief, and (2) the association between the used method of pain relief and experienced fear of childbirth as reported postpartum in low risk labouring women.

METHODS

Secondary analysis of the RAVEL study, a randomised controlled trial comparing remifentanil patient controlled analgesia (PCA) and epidural analgesia to relieve labour pain. The RAVEL study included 409 pregnant women at low risk for obstetric complications at 18 midwifery practices and six hospitals in The Netherlands (NTR 3687). We measured fear of childbirth antepartum and experienced fear of childbirth reported postpartum, using the Wijma Delivery Expectancy/Experience Questionnaire.

RESULTS

Women with fear of childbirth antepartum more frequently requested pain relief compared to women without fear of childbirth antepartum, but this association did not reach statistical significance (adjusted odds ratio (aOR2.0; 95% confidence interval (CI) 0.8-4.6). Women who received epidural analgesia more frequently reported fear of childbirth postpartum compared to women who did not receive epidural analgesia (aOR3.5; CI 1.5-8.2), while the association between remifentanil-PCA and fear of childbirth postpartum was not statistically significant (aOR1.7; CI 0.7-4.3).

CONCLUSIONS

Women with fear of childbirth antepartum more frequently requested pain relief compared to women without fear of childbirth antepartum, but this association was not statistically significant. Women who received pharmacological pain relief more frequently reported that they had experienced fear of childbirth during labour compared to women who did not receive pain relief. Based on our data epidural analgesia with continuous infusion does not seem to be preferable over remifentanil-PCA as method of pain relief when considering fear of childbirth postpartum.

TRIAL REGISTRATION

Netherlands Trial Register 3687 ; Register date: 5 Nov 2012.

Parenteral opioids for maternal pain management in labour

BACKGROUND

Parenteral opioids (intramuscular and intravenous drugs including patient-controlled analgesia) are used for pain relief in labour in many countries throughout the world. This review is an update of a review first published in 2010.

OBJECTIVES

To assess the effectiveness, safety and acceptability to women of different types, doses and modes of administration of parenteral opioid analgesia in labour. A second objective is to assess the effects of opioids in labour on the baby in terms of safety, condition at birth and early feeding.

SEARCH METHODS

We searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (11 May 2017) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials examining the use of intramuscular or intravenous opioids (including patient-controlled analgesia) for women in labour. Cluster-randomised trials were also eligible for inclusion, although none were identified. We did not include quasi-randomised trials. We looked at studies comparing an opioid with another opioid, placebo, no treatment, other non-pharmacological interventions (transcutaneous electrical nerve stimulation (TENS)) or inhaled analgesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trials for inclusion and risk of bias, extracted data and checked them for accuracy. We assessed the quality of each evidence synthesis using the GRADE approach.

MAIN RESULTS

We included 70 studies that compared an opioid with placebo or no treatment, another opioid administered intramuscularly or intravenously or compared with TENS applied to the back. Sixty-one studies involving more than 8000 women contributed data to the review and these studies reported on 34 different comparisons; for many comparisons and outcomes only one study contributed data. All of the studies were conducted in hospital settings, on healthy women with uncomplicated pregnancies at 37 to 42 weeks' gestation. We excluded studies focusing on women with pre-eclampsia or pre-existing conditions or with a compromised fetus. Overall, the evidence was graded as low- or very low-quality regarding the analgesic effect of opioids and satisfaction with analgesia; evidence was downgraded because of study design limitations, and many of the studies were underpowered to detect differences between groups and so effect estimates were imprecise. Due to the large number of different comparisons, it was not possible to present GRADE findings for every comparison.For the comparison of intramuscular pethidine (50 mg/100 mg) versus placebo, no clear differences were found in maternal satisfaction with analgesia measured during labour (number of women satisfied or very satisfied after 30 minutes: 50 women; 1 trial; risk ratio (RR) 7.00, 95% confidence interval (CI) 0.38 to 128.87, very low-quality evidence), or number of women requesting an epidural (50 women; 1 trial; RR 0.50, 95% CI 0.14 to 1.78; very low-quality evidence). Pain scores (reduction in visual analogue scale (VAS) score of at least 40 mm: 50 women; 1 trial; RR 25, 95% CI 1.56 to 400, low-quality evidence) and pain measured in labour (women reporting pain relief to be "good" or "fair" within one hour of administration: 116 women; 1 trial; RR 1.75, 95% CI 1.24 to 2.47, low-quality evidence) were both reduced in the pethidine group, and fewer women requested any additional analgesia (50 women; 1 trial; RR 0.71, 95% CI 0.54 to 0.94, low-quality evidence).There was limited information on adverse effects and harm to women and babies. There were few results that clearly showed that one opioid was more effective than another. Overall, findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour. Opioid drugs were associated with maternal nausea, vomiting and drowsiness, although different opioid drugs were associated with different adverse effects. There was no clear evidence of adverse effects of opioids on the newborn. We did not have sufficient evidence to assess which opioid drug provided the best pain relief with the least adverse effects.

AUTHORS' CONCLUSIONS

Though most evidence is of low- or very-low quality, for healthy women with an uncomplicated pregnancy who are giving birth at 37 to 42 weeks, parenteral opioids appear to provide some relief from pain in labour but are associated with drowsiness, nausea, and vomiting in the woman. Effects on the newborn are unclear. Maternal satisfaction with opioid analgesia was largely unreported. The review needs to be examined alongside related Cochrane reviews. More research is needed to determine which analgesic intervention is most effective, and provides greatest satisfaction to women with acceptable adverse effects for mothers and their newborn.

Regional variations in childbirth interventions in the Netherlands: a nationwide explorative study

BACKGROUND

Although interventions in childbirth are important in order to prevent neonatal and maternal morbidity and mortality, non-indicated use may cause avoidable harm. Regional variations in intervention rates, which cannot be explained by maternal characteristics, may indicate over- and underuse. The aim of this study is to explore regional variations in childbirth interventions in the Netherlands and their associations with interventions and adverse outcomes, controlled for maternal characteristics.

METHODS

Childbirth intervention rates were compared between twelve Dutch regions, using data from the national perinatal birth register for 2010-2013. All single childbirths from 37 weeks' gestation onwards were included. Primary outcomes were induction and augmentation of labour, pain medication, instrumental birth, caesarean section (prelabour, intrapartum) and paediatric involvement. Secondary outcomes were adverse neonatal and maternal outcomes. Multivariable logistic regression analyses were used to adjust for maternal characteristics. Associations were expressed in Spearman's rank correlation coefficients.

RESULTS

Most variation was found for type of pain medication and paediatric involvement. Epidural analgesia rates varied from between 12 and 38% (nulliparous) and from between 5 and 14% (multiparous women). These rates were negatively correlated with rates of other pharmacological pain relief, which varied from between 15 and 43% (nulliparous) and from between 10 and 27% (multiparous). Rates of paediatric involvement varied from between 37 and 60% (nulliparous) and from between 26 and 43% (multiparous). For instrumental vaginal births, rates varied from between 16 and 19% (nulliparous) and from between 3 and 4% (multiparous). For intrapartum caesarean section, the variation was 13-15% and 5-6%, respectively. A positive correlation was found between intervention rates in midwife-led and obstetrician-led care at the onset of labour within the same region. Adverse neonatal and maternal outcomes were not lower in regions with higher intervention rates. Higher augmentation of labour rates correlated with higher rates of severe postpartum haemorrhage.

CONCLUSIONS

Most variation was found for type of pain medication and paediatric involvement, and least for instrumental vaginal births and intrapartum caesarean sections. Care providers and policy makers should critically audit remarkable variations, since these may be unwarranted. Limited variation for some interventions may indicate consensus for their use. Further research should focus on variations in evidence-based interventions and indications for the use of interventions in childbirth.

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.

[Pain therapy during labour]

To date the gold standard of treating labour pain is regional analgesia by application of epidural analgesia. When offering epidural analgesia, the programmed intermittent epidural bolus (PIEB) is more effective in terms of pain reduction, less motor blocks and higher satisfaction of the parturient compared to continuous application via perfusor pump. An upcoming alternative to epidural analgesia is remifentanil, a short acting and potent opioid. Remifentanil, however, requires haemodynamic monitoring as cardiac and respiratory impairment has been described. Nitrous oxide has been used for decades in the Anglosphere but it is a greenhouse gas, and interactions with Vitamin B₁₂ are possible. Using novel extraction systems, nitrous oxide has become more attractive for treatment of the initial phase of labour pain in Central Europe. In order to provide the parturient with the best possible and with a tailored pain concept an interdisciplinary approach with obstetricians, midwives and anaesthesiologists is required.

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.