Labour analgesia. A risk-benefit analysis

Results of Induction of Labor with Prostaglandins E1 and E2 (The RIPE Study): A Real-World Data Analysis of Obstetrical Effectiveness and Clinical Outcomes of Pharmacological Induction of Labor with Vaginal Inserts

Despite extensive knowledge of the mechanisms responsible for childbirth, the course of labor induction is often unpredictable. Therefore, labor induction protocols using prostaglandin analogs have been developed and tested to assess their effectiveness in labor induction unequivocally. A total of 402 women were collected into two groups-receiving vaginal Misoprostol or vaginal Dinoprostone for induction of labor (IOL). Then, the patients were compared in groups depending on the agent they received and their gestational age. Most patients delivered within 48 h, and most of these patients had vaginal parturition. Patients who received the Dinoprostone vaginal insert required statistically significantly more oxytocin administration than patients who received the Misoprostol vaginal insert. Patients who received the Misoprostol vaginal insert used anesthesia during labor statistically more often. Patients who received Misoprostol vaginal inserts had a statistically significantly shorter time to delivery than those with Dinoprostone vaginal inserts. The prevalence of hyperstimulation was similar in all groups and remained low. Vaginal Misoprostol-based IOL is characterized by a shortened time to delivery irrespective of the parturition type, and a lower need for oxytocin augmentation, but also by an increased demand for intrapartum analgesia administration. A vaginal Dinoprostone-based IOL protocol might be considered a more harmonious and desirable option in modern perinatal care.

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.

Effects of maternal epidural analgesia on the neonate--a prospective cohort study

Background

Epidural analgesia is one of the most popular modes of analgesia for child birth. There are controversies regarding adverse effects and safety of epidural analgesia. This study was conducted to study the immediate effects of the maternal epidural analgesia on the neonate during early neonatal phase.

Methods

A prospective cohort study of 100 neonates born to mothers administered epidural analgesia were compared with 100 neonates born to mothers not administered epidural analgesia in terms of passage of urine, initiation of breast feeding, birth asphyxia and incidence of instrumentation.

Results

There was significant difference among the two groups in the passage of urine (P value 0.002) and incidence of instrumentation (P value 0.010) but there was no significant difference in regards to initiation of breast feeding and birth asphyxia.

Conclusions

Epidural analgesia does not have any effect on the newborns in regards to breast feeding and birth asphyxia but did have effects like delayed passage of urine and increased incidence of instrumentation.

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.

Retrospective analysis of high-dose intrathecal morphine for analgesia after pelvic surgery

BACKGROUND

The effectiveness of intrathecal opioids (ITOs) for postoperative analgesia has been limited by reduced opioid dosing because of opioid-related side effects, most importantly respiratory depression. To overcome these limitations, high-dose intrathecal morphine was combined with a continuous intravenous (IV) postoperative naloxone infusion. The aim of the present chart analysis was to investigate the safety and efficacy of high-dose ITOs combined with IV naloxone compared with IV opioid analgesia alone.

METHODS

A retrospective chart analysis was performed on 121 female patients requiring major pelvic surgery. Ninety-eight patients received a single injection of high-dose ITOs before administration of typical general anesthesia, followed by an IV naloxone infusion at 5 µg⁄kg⁄h started post-ITO and continued for 22 h postoperatively. Twenty-three patients were given IV morphine (IVM) for postoperative analgesia and served as a reference group. Postoperative pain relief, analgesic consumption and ability to ambulate were assessed for 48 h postoperatively. Treatment safety was assessed by monitoring opioid-related side effects and vital signs. Data are presented as mean ± SD.

RESULTS

Mean ITOs given were morphine 1.1±0.2 mg combined with fentanyl 49 ± 6 µg. The mean worst pain visual analogue scale score in the first 12 h postoperatively was 0.2 ± 0.90 in the ITO group versus 4.3 ± 3.0 in the IVM group (P<0.05). On postoperative day 2, the mean worst pain visual analogue scale score was only 1 ± 1.8 in the ITO group versus 4.1 ± 2.6 in the IVM group (P<0.05). Analgesic requirements were reduced in the ITO group. In the first 24 h, the ITO group used 6.8±10.2 morphine equivalents (mg IV) versus 76.1 ± 44.4 in the IVM group (P<0.05). All patients in the ITO group were able to ambulate in the first 12 h postoperatively compared with 17⁄23 in the IVM group. There was a higher incidence of opioid-related sedation in the IVM group. Other opioid-related side effects were infrequent and minor in both groups.

CONCLUSIONS

High-dose ITOs combined with a postoperative IV naloxone infusion provided excellent analgesia for major pelvic surgery. The IV naloxone infusion combined with high-dose ITOs appeared to control opioid side effects without affecting analgesia.

[Epidural analgesia in obstetrics: is there an effect on labor and delivery?]

BACKGROUND AND OBJECTIVE

Epidural analgesia is routinely used in obstetrics but has been blamed for possible effects on labor that lead to greater use of instruments or conversion to cesarean delivery. We aimed to assess this possibility in a cohort of obstetric patients receiving or not receiving epidural analgesia.

PATIENTS AND METHODS

Prospectively enrolled full-term obstetric patients were distributed in 2 groups according to whether they received epidural analgesia or not. We compared maternal and fetal characteristics, obstetric variables, and type of delivery between groups to record the likely causes of difficult labor and delivery and detect a possible influence of epidural analgesia.

RESULTS

Of a total of 602 patients, 462 received epidural analgesia and 140 did not. Epidural analgesia was related to a higher rate of use of instruments but not cesareans (P < .01) and more frequent need for oxytocin (30.7% of the epidural analgesia group vs 0% of the group receiving no epidural analgesia, P < .001). The women receiving analgesia also had a longer mean (SD) duration of the dilatation phase of labor (6.4 [4.2] hours in the epidural group vs 4.7 [3.5] hours in the no-epidural group, P < .01) and of the expulsion phase (1.0 [0.6] hours vs 0.7 [0.6] hours, respectively; P<.01). We observed no effects on the incidence of tearing, rate of episiotomy, or other variables. Predictors of instrumentation or conversion to cesarean delivery were longer duration of the first phase (odds ratio [OR] 1.2; 95% confidence interval [CI], 1.1-1.3), longer duration of the second phase (OR 2.3; 95% CI, 1.3-3.9), and maternal obesity (OR, 1.1; 95% CI, 0.9-1.2). Previous deliveries and initiation of epidural analgesia after the fetus has reached Hodge's first plane decreased risk 2.7-fold and 3.03-fold, respectively.

CONCLUSIONS

Although epidural analgesia has traditionally been associated with a higher incidence of difficult labor and delivery, this association was not unequivocally evident in this cohort of patients. The apparent increase seems to be attributable to such obstetric factors as longer duration of stages of labor, higher body mass index, and first delivery.

[Paracervical block in obstetrics]

OBJECTIVE

To review the most recent and relevant issues concerning paracervical block in obstetrics since 1975 when Jägerhorn described the superficial technique that has become a standard.

DATA SOURCES

Extraction from Pubmed database of articles issued from 1975 to 2005.

DATA SELECTION

The collected articles were selected on the basis of the use of the superficial injection method. The more recent data were selected. The keywords were: paracervical, labour, childbirth, and neonate.

DATA SYNTHESIS

Paracervical block (PCB) is routinely used over the world despite the risk of foetal bradycardia. Bradycardia occurring immediately after the performance of block is short lasting. The reports of few cases of foetal or neonatal deaths have caused many physicians to question its safety. The incidence of bradycardia has dramatically decreased (less than 10%) due to the Jägerhorn superficial injection method. In case of healthy neonate the occurrence of bradycardia is harmless but its mechanism is still imprecise. The intensity an duration of analgesia is poor in comparison with epidural anaesthesia. PCB is a viable alternative to epidural in selected cases.

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.

Economic considerations related to providing adequate pain relief for women in labour: comparison of epidural and intravenous analgesia

Epidural analgesia and intravenous analgesia with opioids are two techniques for providing pain relief for women in labour. Labour pain is comparable to surgical pain in its severity, and epidural analgesia provides better relief from this pain than intravenous analgesia; a meta-analysis quantified this improvement to be 40 mm on a 100mm pain scale during the first stage of labour. Epidural analgesia also has fewer adverse effects. However, providing epidural analgesia for labour pain costs more. The full cost of providing epidural analgesia can be divided into two components: a baseline-cost component, which captures the costs of hospital care to parturients receiving intravenous analgesia for labour pain; and an incremental-cost component, which estimates the costs arising from incremental care specific to epidural analgesia. The baseline component may be constructed using hospital cost-accounting data pertaining to actual obstetric patients. The incremental component is constructed from a set of recognised complications of epidural and intravenous analgesia, associated incidence rates and estimates of the costs involved, from society's perspective. The incremental expected cost per patient to society of providing epidural analgesia was calculated to be approximately $US338 (1998 values). This cost difference results primarily from increased professional costs (and is particularly sensitive to the method used to estimate the cost of anaesthesia professional services) and increased complication costs associated with epidural analgesia. A rational social policy for providing labour analgesia must weigh the value of improved pain relief from epidural analgesia against the increased cost of epidural analgesia.

A comparison of the hemodynamic effects of paracervical block and epidural anesthesia for labor analgesia

BACKGROUND

Both paracervical block (PCB) and epidural analgesia are sometimes associated with hemodynamic effects potentially harmful to the well-being of the fetus. Our study was designed to test the hypothesis that PCB would have a more profound effect on maternal and fetal blood flow than epidural analgesia.

METHODS

Forty-four healthy primiparous parturients were randomized to receive either PCB (n=21) or epidural analgesia (n= 23) with 25 or 30 mg of bupivacaine, respectively, for labor analgesia. Maternal blood pressure and fetal heart rate were recorded. Blood flow was measured using a color Doppler device. The blood flow measurements consisted of assessment of the pulsatility indices (PI) of the right maternal femoral artery and the main branch of the uterine artery (placental side), the umbilical artery and the fetal middle cerebral artery. The measurements were performed before administration of analgesia and approximately 15-20 min later after the onset of analgesia.

RESULTS

Both methods provided in general good analgesia, but rescue medication was required more often after PCB. Epidural analgesia decreased maternal blood pressure more than PCB and the PI of maternal femoral artery decreased after onset of epidural analgesia, indicating epidural-induced vasodilation. The PI of the uterine artery increased after the onset of PCB, indicating vasoconstriction of this artery. No significant adverse effects or differences in the well-being of the newborn were observed, as indicated by similar Apgar scores and pH-status.

CONCLUSION

There were small differences in the effects of PCB and epidural analgesia on uteroplacental circulation as well as on maternal hemodynamics. PCB may have a vasoconstrictive effect on the uterine artery. This and the fact that the parturients required rescue analgesia more frequently after PCB than after epidural block speaks for the feasibility of the latter in obstetrics.

Analgesia and anaesthesia in childbirth: obscurantism and obfuscation

The terms 'analgesia' and 'anaesthesia' have been defined by emphasizing differing aspects of their effects. The distinction between these interventions has not been clarified by their definitions. The historical remedies for pain were similarly unclear. This lack of clarity is apparent in the introduction of chloroform in childbirth, which has much in common with the introduction and effects of epidural analgesia. The reasons for and benefits of this lack of clarity are examined.