Effects of epidural lidocaine analgesia on labor and delivery: a randomized, prospective, controlled 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.

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.

A Comparison between Pre-Incisional and Intraoperative Lidocaine Infiltration on Post-Incisional Surgical Pain in Microdiscectomy Surgery: A Randomized Clinical Trial Study

Objectives

Effective postoperative pain control in microdiscectomy surgery is crucial to managing the disease and improving the patient's quality of life. Therefore, this study aimed to assess the potential effectiveness of 2% lidocaine in reducing pain immediately after discectomy surgery.

Methods

A total of 60 patients who underwent microdiscectomy surgery were enrolled in this randomized clinical trial study. They were randomly assigned to three groups: one group received lidocaine just before the incision, another group received lidocaine just before closing the incision, and the third group served as the control. Pain scores were measured at 1, 2, 3, 4, 8, and 12 h after the surgery using a Visual Analogue Scale.

Results

The demographic and clinical characteristics of the study population, including age, weight, length of surgery, gender, and history of diabetes, hypertension, and previous surgery, were comparable across all three groups (P>0.05). There was a significant reduction in pain scores over time in the groups that received lidocaine before (P<0.001) and during surgery (P=0.002). Moreover, there were significant differences in pain scores at all time points among the three groups. Both groups receiving lidocaine showed significantly lower pain scores than the control group (Pbefore surgery=0.005 and Pduring surgery<0.001). However, no significant difference was observed between the groups receiving lidocaine (P=0.080).

Conclusion

These findings highlight the effectiveness of a local injection of 2% lidocaine either before or during the surgery in managing post-incisional surgical pain after discectomy.

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.

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.

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.

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.

Epidural Labor Analgesia and Maternal Fever

Women receiving an epidural for labor analgesia are at increased risk for intrapartum fever. This relationship has been supported by observational, before and after, and randomized controlled trials. The etiology is not well understood but is likely a result of noninfectious inflammation as studies have found women with fever have higher levels of inflammatory markers. Maternal pyrexia may change obstetric management and women are more likely to receive antibiotics or undergo cesarean delivery. Maternal pyrexia is associated with adverse neonatal outcomes. With these consequences, understanding and preventing maternal fever is imperative.

The Effect of Epidural Analgesia Alone and in Association With Other Variables on the Risk of Cesarean Section

Introduction:

Epidural analgesia (EA) is the most widespread pharmacologic method of labor pain relief. There remains disagreement, however, regarding its adverse effects. The objective of this study was to determine the effect of EA administration on the risk of cesarean delivery and its causes (e.g., stalled labor, risk of loss of fetal well-being, among others) and the degree to which this effect may be modulated by mother-, newborn-, and labor-related variables.

Method:

A retrospective cohort observational study was conducted including all deliveries in a Spanish public hospital between March 2010 and March 2013 ( N = 2,450; EA = 562, non-EA = 1,888).

Results:

Risk of a cesarean section was significantly increased by EA administration (odds ratio [ OR] = 2.673; p < .0001). The percentage of cesarean deliveries due to the risk of loss of fetal well-being was significantly higher in the EA (47.8%) versus non-EA group (27.5%; OR = 1.739; p = 0.0012,). The EA-associated risk of cesarean section was not significantly modified as a function of maternal age or parity, fetal position, newborn weight, weeks of gestation, or sedation administration alone. However, these variables in combination may increase the risk. We present multivariate models for each group that account for these variables, allowing for estimation of the risk of a cesarean delivery if EA is administered.

Conclusion:

EA is associated with an increased risk of cesarean delivery. Other variables in combination (maternal age or parity, fetal position, newborn weight, weeks of gestation, or sedation administration) may increase this risk.

Adjustment for compliance behavior in trials of epidural analgesia in labor using instrumental variable meta-analysis

OBJECTIVES

Intention-to-treat (ITT) analysis of randomized controlled trials (RCTs) may cause bias when compliance is poor. Noncompliance describes failure to comply with allocation in the intervention arm, and contamination describes uptake of the intervention in the control arm. Instrumental variable (IV) analysis can be applied in addition to the primary ITT analysis to estimate the causal effect adjusted for noncompliance and contamination, assuming that noncompliers would have had the same treatment benefit as compliers. We aimed to compare ITT and IV meta-analysis of the association between epidural analgesia in labor and cesarean section.

STUDY DESIGN AND SETTING

The study was restricted to 27 trials in a Cochrane Systematic Review. The association between epidural analgesia in labor and cesarean section was calculated using ITT and IV analyses. Pooled risk ratios (RRs) were calculated using fixed-effects meta-analysis.

RESULTS

In 18 trials with compliance data, noncompliance was 23% and contamination was 27%. In 10 trials with outcome data stratified by compliance, the pooled RR for cesarean section following epidural analgesia was 1.37 [95% confidence interval (CI): 1.00, 1.89; P = 0.049] using IV compared with 1.19 (95% CI: 0.93, 1.51; P = 0.16) using ITT.

CONCLUSION

ITT meta-analysis underestimates the effect of receiving epidural analgesia in labor on cesarean section compared with IV meta-analysis.

The effect of epidural analgesia on labour, mode of delivery and neonatal outcome in nullipara of India, 2011-2014

AIMS

This study aimed to evaluate the effect of ropivacaine epidural analgesia on duration and outcome of labour in nulliparous parturients of India with parturient not receiving any analgesia.

SETTINGS AND DESIGN

One hundred and twenty nulliparous parturient in established labour at full term with a singleton vertex presentation were assigned to the study. Parturients who request epidural analgesia were allocated in the epidural group (n=60), whereas those not enthusiastic to labour analgesia were allocated in the control group (n=60).

MATERIALS AND METHODS

Epidural analgesia was provided by a bolus injection of 10 ml of ropivacaine 0.2% and 50μg fentanyl and maintained by using a continuous infusion of ropivacaine 0.1% with fentanyl 2μl/ml at a 10ml/hour rate. The outcomes were duration of labour, incidence of cesarean sections and instrumental vaginal delivery and neonatal outcome.

STATISTICAL ANALYSIS USED

Statistical analysis was conducted using unpaired student t-test and chi-square test as required. All tests of significance were performed using two-tailed probability tests. Differences were considered significant when p-value was <0.05.

RESULTS

The two groups were comparable in terms of socio-demographic data. The mean duration of first stage of labour was shorter in epidural group (4.83 ± 1.59 h) compared with control group (5.48 ± 1.56 h) while the duration of second stage of labour was prolong in epidural group (33.13 ± 12.78 min) as compared to control (27.53 ± 11.73 min). Instrumental vaginal or caesarean delivery rate did not increase in the epidural group. The APGAR scores at 5 min were statistically similar in both groups.

CONCLUSION

Epidural analgesia by ropivacaine in Indian nulliparous resulted in shorter duration of first stage and prolongs duration of second stage of labour compared with parturients without analgesia; however, instrumental vaginal or caesarean delivery rate does not increase in the epidural group.

Epidural analgesia during labor vs no analgesia: A comparative study

BACKGROUND

Epidural analgesia is claimed to result in prolonged labor. Previous studies have assessed epidural analgesia vs systemic opioids rather than to parturients receiving no analgesia. This study aimed to evaluate the effect of epidural analgesia on labor duration compared with parturients devoid of analgesia.

METHODS

One hundred sixty nulliparous women in spontaneous labor at full term with a singleton vertex presentation were assigned to the study. Parturients who request epidural analgesia were allocated in the epidural group, whereas those not enthusiastic to labor analgesia were allocated in the control group. Epidural analgesia was provided with 20 mL bolus 0.5% epidural lidocaine plus fentanyl and maintained at 10 mL for 1 h. Duration of the first and second stages of labor, number of parturients receiving oxytocin, maximal oxytocin dose required for each parturient, numbers of instrumental vaginal, vacuum-assisted, and cesarean deliveries and neonatal Apgar score were recorded.

RESULTS

There was no statistical difference in the duration of the active-first and the second stages of labor, instrumental delivery, vacuum-assisted or cesarean delivery rates, the number of newborns with 1-min and 5-min Apgar scores less than 7 between both groups and number of parturients receiving oxytocin, however, the maximal oxytocin dose was significantly higher in the epidural group.

CONCLUSION

Epidural analgesia by lidocaine (0.5%) and fentanyl does not prolong labor compared with parturients without analgesia; however, significant oxytocin augmentation is required during the epidural analgesia to keep up the aforementioned average labor duration.

Epidural versus non-epidural or no analgesia 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 regarding unintended adverse effects on the mother and infant.

OBJECTIVES

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

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (31 March 2011).

SELECTION CRITERIA

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

DATA COLLECTION AND ANALYSIS

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. We entered data into RevMan and double checked it for accuracy. Primary analysis was by intention to treat; we conducted subgroup and sensitivity analyses where substantial heterogeneity was evident.

MAIN RESULTS

We included 38 studies involving 9658 women; all but five studies compared epidural analgesia with opiates. Epidural analgesia was found to offer better pain relief (mean difference (MD) -3.36, 95% confidence interval (CI) -5.41 to -1.31, three trials, 1166 women); a reduction in the need for additional pain relief (risk ratio (RR) 0.05, 95% CI 0.02 to 0.17, 15 trials, 6019 women); a reduced risk of acidosis (RR 0.80, 95% CI 0.68 to 0.94, seven trials, 3643 women); and a reduced risk of naloxone administration (RR 0.15, 95% CI 0.10 to 0.23, 10 trials, 2645 women). However, epidural analgesia was associated with an increased risk of assisted vaginal birth (RR 1.42, 95% CI 1.28 to 1.57, 23 trials, 7935 women), maternal hypotension (RR 18.23, 95% CI 5.09 to 65.35, eight trials, 2789 women), motor-blockade (RR 31.67, 95% CI 4.33 to 231.51, three trials, 322 women), maternal fever (RR 3.34, 95% CI 2.63 to 4.23, six trials, 2741 women), urinary retention (RR 17.05, 95% CI 4.82 to 60.39, three trials, 283 women), longer second stage of labour (MD 13.66 minutes, 95% CI 6.67 to 20.66, 13 trials, 4233 women), oxytocin administration (RR 1.19, 95% CI 1.03 to 1.39, 13 trials, 5815 women) and an increased risk of caesarean section for fetal distress (RR 1.43, 95% CI 1.03 to 1.97, 11 trials, 4816 women). There was no evidence of a significant difference in the risk of caesarean section overall (RR 1.10, 95% CI 0.97 to 1.25, 27 trials, 8417 women), long-term backache (RR 0.96, 95% CI 0.86 to 1.07, three trials, 1806 women), Apgar score less than seven at five minutes (RR 0.80, 95% CI 0.54 to 1.20, 18 trials, 6898 women), and maternal satisfaction with pain relief (RR 1.31, 95% CI 0.84 to 2.05, seven trials, 2929 women). We found substantial heterogeneity for the following outcomes: pain relief; maternal satisfaction; need for additional means of pain relief; length of second stage of labour; and oxytocin augmentation. This could not be explained by subgroup or sensitivity analyses, where data allowed analysis. No studies reported on rare but potentially serious adverse effects of epidural analgesia.

AUTHORS' CONCLUSIONS

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.

Parenteral opioids for maternal pain relief in labour

BACKGROUND

Parenteral opioids are used for pain relief in labour in many countries throughout the world.

OBJECTIVES

To assess the acceptability, effectiveness and safety of different types, doses and modes of administration of parenteral opioids given to women in labour.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (January 2010) 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. We looked at studies comparing an opioid with placebo or another opioid.

DATA COLLECTION AND ANALYSIS

At least two review authors independently assessed study eligibility, collected data and assessed risk of bias.

MAIN RESULTS

We included 54 studies involving more than 7000 women that compared an opioid with placebo or another opioid administered intramuscularly or intravenously. The 54 studies reported on 27 different comparisons, and for many outcomes only one study contributed data. Overall the evidence was of poor quality regarding the analgesic effect of opioids, satisfaction with analgesia, adverse effects and harm to women and babies. There were few statistically significant results. Many of the studies had small sample sizes, and low statistical power. Overall, findings indicated that parenteral opioids provided some pain relief and moderate satisfaction with analgesia in labour, although up to two-thirds of women who received opioids reported moderate or severe pain and/or poor or moderate pain relief one or two hours after administration. 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

Parenteral opioids provide some relief from pain in labour but are associated with adverse effects. Maternal satisfaction with opioid analgesia was largely unreported but appeared moderate at best. We did not examine the effectiveness and safety of parenteral opioids compared with other methods of pain relief in labour and this 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 events for mothers and their newborns.

The effect of epidural analgesia on labor progress and outcome in nulliparous women

OBJECTIVE

The present study was designed to investigate the influence of epidural analgesia on labor progress and outcome in nulliparous women.

METHODS

A population-based study comparing women with and without epidural analgesia was conducted. Deliveries occurred during 1988-2006 at the Soroka University Medical Center. A multivariable logistic regression model with backward elimination was constructed to control for confounders.

RESULTS

During the study period there were 39 498 deliveries; epidural analgesia was given in 9960 (25.2%) of these. Using a multivariable analysis with backward elimination, the following conditions were significantly associated with the use of epidural analgesia: advanced maternal age, oligohydramnios, premature rupture of membranes, induction of labor, and Jewish (vs. Bedouin) ethnicity. These patients were more likely to deliver by cesarean delivery (CD; OR = 1.4, 95% CI 1.3-1.5; p < 0.001) and vacuum extraction (OR = 1.5, 95% CI 1.4-1.7; p < 0.001). After controlling for possible confounders such as macrosomia, failed induction, hypertensive disorders, gestational diabetes, maternal age, labor dystocia, and ethnicity, epidural analgesia was not found to be an independent risk factor for CD but rather a protective factor (OR = 0.9, 95% CI 0.8-0.9; p = 0.038). When vacuum extraction was the outcome variable, epidural analgesia was documented as an independent risk factor (OR = 1.1, 95% CI 1.01-1.3; p = 0.04).

CONCLUSIONS

Epidural analgesia in nulliparous parturients increases the risk for labor dystocia and accordingly is an independent risk factor for vacuum extraction. Nevertheless, it does not pose an independent risk for cesarean delivery.

Epidural versus non-epidural or no analgesia 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 regarding unintended adverse effects on the mother and infant.

OBJECTIVES

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

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group Trials Register (June 2005).

SELECTION CRITERIA

Randomised controlled trials comparing all modalities of epidural with any form of pain relief not involving regional blockade, or no pain relief in labour.

DATA COLLECTION AND ANALYSIS

Two of the review authors independently assessed trials for eligibility, methodological quality and extracted all data. Data were entered into RevMan and double checked. Primary analysis was by intention-to-treat; sensitivity analyses excluded trials with > 30% of women receiving un-allocated treatment.

MAIN RESULTS

Twenty-one studies involving 6664 women were included, all but one study compared epidural analgesia with opiates. For technical reasons, data on women's perception of pain relief in labour could only be included from one study which found epidural analgesia to offer better pain relief than non-epidural analgesia (weighted mean difference (WMD) -2.60, 95% confidence interval (CI) -3.82 to -1.38, 1 trial, 105 women). However, epidural analgesia was associated with an increased risk of instrumental vaginal birth (relative risk (RR) 1.38, 95% CI 1.24 to 1.53, 17 trials, 6162 women). There was no evidence of a significant difference in the risk of caesarean delivery (RR 1.07, 95% CI 0.93 to 1.23, 20 trials, 6534 women), long-term backache (RR 1.00, 95% CI 0.89 to 1.12, 2 trials, 814 women), low neonatal Apgar scores at five minutes (RR 0.70, 95% CI 0.44 to 1.10, 14 trials, 5363 women), and maternal satisfaction with pain relief (RR 1.18 95% CI 0.92 to 1.50, 5 trials, 1940 women). No studies reported on rare but potentially serious adverse effects of epidural analgesia.

AUTHORS' CONCLUSIONS

Epidural analgesia appears to be effective in reducing pain during labour. However, women who use this form of pain relief are at increased risk of having an instrumental delivery. Epidural analgesia had no statistically significant impact on the risk of caesarean section, maternal satisfaction with pain relief and long-term backache and did not appear to have an immediate effect on neonatal status as determined by Apgar scores. Further research may be helpful to evaluate rare but potentially severe adverse effects of epidural analgesia on women in labour and long-term neonatal outcomes.