Intramuscular opioids for maternal pain relief in labour: a randomised controlled trial comparing pethidine with diamorphine

Meperidine Compared With Nitrous Oxide for Intrapartum Pain Relief in Multiparous Patients: A Randomized Controlled Trial

OBJECTIVE

To compare the efficacy and adverse effects of intravenous meperidine and inhaled nitrous oxide for intrapartum analgesia in multiparous patients.

METHODS

This randomized controlled trial was conducted in the delivery ward of a university teaching medical center in Afula, Israel. Multiparous patients with term, singleton pregnancies who were in labor were randomized in a 1:1 ratio to 50 mg intravenous meperidine or inhaled nitrous oxide. The primary outcome was pain intensity 20-30 minutes after analgesic administration, measured on a visual analog scale (VAS) from 0 to 10 cm. Secondary outcomes included the need for additional analgesia, labor length, delivery mode, patient satisfaction, and maternal and neonatal adverse effects. To detect a 1-cm (±2.6) difference in VAS score between the groups, 214 total participants were needed to achieve 80% power with an alpha of 0.05.

RESULTS

From August 2016 through May 2019, 214 participants were enrolled. Fourteen were excluded after randomization. Of the 200 analyzed, 102 received nitrous oxide, and 98 received intravenous meperidine. Demographic and obstetric variables were comparable between the two groups. The VAS score 20-30 minutes after analgesic administration did not differ between the groups (7.7±2.3 cm and 7.6±2.7 cm in the nitrous oxide and meperidine groups, respectively, P=.89). There were no significant differences between the groups in the rate of additional analgesic use, labor length, delivery mode, Apgar scores, rate of breastfeeding, patient satisfaction, or maternal and neonatal adverse effects.

CONCLUSION

Pain intensity was comparable in multiparous patients 20-30 minutes after administration of meperidine and nitrous oxide. Adverse effects were also comparable.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT02783508.

Pharmacologic and non-pharmacologic labor pain management techniques in a resource-limited setting: A systematic review

Background

Despite improvement in pain management programs, labor pain is mostly ignored especially in low and middle-income countries.

Methods

The aim of this study is to establish a clear clinical working guideline for labor pain management in resource limited settings. This systematic review is conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline 2020. After formulating clear criteria for the evidences to be included an appropriate method of searching was conducted by using the Pub Med, Google scholar and Cochrane library using the following MeSH terms: (‘Parenteral opioids’ AND′ Labor pain’, ‘Labor’ AND ‘Pain management, ‘Non-pharmacologic methods ‘AND ‘Labor pain’, ‘Labor pain management AND massage therapy). The study quality of literatures was categorized based on WHO 2011 level of evidence and degree of recommendation. Final conclusions and recommendations are done with the analysis of risk and benefits of alternative management strategies for non-regional techniques of labor pain management. The study is registered with research registry unique identifying number (UIN) of 1267 “https://www.researchregistry.com/browse-the-registry#registryofsystematicreviewsmeta-analyses/.” and the study is moderate based on AMSTAR 2 quality assessment criteria/https://amstar.ca/Amstar_Checklist.php.

Discussion

Combined forms of Non-pharmacologic and selected low dose pharmacologic approaches of labor pain management, provides significant benefits to women and their infants. During provision of labor analgesia complications may happen and the service provider should involve in the management of those complications.

Conclusion

This study has a paramount importance to practice the most reliable, available and cost effective method of labor analgesia.

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Appropriate history and physical examinations are crucial to avoid contraindicated medications in labor pain managment.

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Combined non-pharmacologic methods with a lower dose of indicated drugs provides significant advantages for both mothers and their infants.

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Using available and cost effective labor pain managment with minimal complications has paramount importance in resource limited setting.

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During provision of labor analgesia service provider should aware of complications to intervene at theright time.

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.

The impact of the National Institute for Health Research Health Technology Assessment programme, 2003-13: a multimethod evaluation

BACKGROUND

The National Institute for Health Research (NIHR) Health Technology Assessment (HTA) programme supports research tailored to the needs of NHS decision-makers, patients and clinicians. This study reviewed the impact of the programme, from 2003 to 2013, on health, clinical practice, health policy, the economy and academia. It also considered how HTA could maintain and increase its impact.

METHODS

Interviews (n = 20): senior stakeholders from academia, policy-making organisations and the HTA programme. Bibliometric analysis: citation analysis of publications arising from HTA programme-funded research. Researchfish survey: electronic survey of all HTA grant holders. Payback case studies (n = 12): in-depth case studies of HTA programme-funded research.

RESULTS

We make the following observations about the impact, and routes to impact, of the HTA programme: it has had an impact on patients, primarily through changes in guidelines, but also directly (e.g. changing clinical practice); it has had an impact on UK health policy, through providing high-quality scientific evidence - its close relationships with the National Institute for Health and Care Excellence (NICE) and the National Screening Committee (NSC) contributed to the observed impact on health policy, although in some instances other organisations may better facilitate impact; HTA research is used outside the UK by other HTA organisations and systematic reviewers - the programme has an impact on HTA practice internationally as a leader in HTA research methods and the funding of HTA research; the work of the programme is of high academic quality - the Health Technology Assessment journal ensures that the vast majority of HTA programme-funded research is published in full, while the HTA programme still encourages publication in other peer-reviewed journals; academics agree that the programme has played an important role in building and retaining HTA research capacity in the UK; the HTA programme has played a role in increasing the focus on effectiveness and cost-effectiveness in medicine - it has also contributed to increasingly positive attitudes towards HTA research both within the research community and the NHS; and the HTA focuses resources on research that is of value to patients and the UK NHS, which would not otherwise be funded (e.g. where there is no commercial incentive to undertake research). The programme should consider the following to maintain and increase its impact: providing targeted support for dissemination, focusing resources when important results are unlikely to be implemented by other stakeholders, particularly when findings challenge vested interests; maintaining close relationships with NICE and the NSC, but also considering other potential users of HTA research; maintaining flexibility and good relationships with researchers, giving particular consideration to the Technology Assessment Report (TAR) programme and the potential for learning between TAR centres; maintaining the academic quality of the work and the focus on NHS need; considering funding research on the short-term costs of the implementation of new health technologies; improving the monitoring and evaluation of whether or not patient and public involvement influences research; improve the transparency of the priority-setting process; and continuing to monitor the impact and value of the programme to inform its future scientific and administrative development.

A randomized controlled trial comparing Pentazocine and Chamomilla recutita for labor pain relief

BACKGROUND

Traditional birth attendants in Pakistan sometimes use a homeopathic remedy, Chamomilla for labor pain relief. Our study compares this homeopathic remedy for pain relief in labor with a commonly used parenteral analgesic in a hospital setting. No systematic study has been conducted previously to study the effect of chamomile, which may be affordable and available in community settings.

METHODS

A double blind randomized controlled trial was carried out at Islamic International Medical College Trust. Ninety-nine normal pregnant women were randomly assigned into three groups. Each group received one of the three trial drugs; Chamomile, Pentazocine or placebo. The efficacy of labor analgesia was assessed by using Visual Analogue Scale (VAS) for pain intensity. Indicators of maternal and child health were recorded as were adverse effects of the drugs.

RESULTS

Mean pain scores in the three groups were calculated and compared. The difference in mean VAS scores in Pentazocine and Chamomilla recutita group as compared with placebo was not statistically significant. No significant adverse effects were noticed in any group except slight headache and dizziness in three parturients in Pentazocine group.

CONCLUSION

Neither Pentazocine, or Chamomilla recutita offer substantial analgesia during labor.

Risks versus benefits of gastrointestinal endoscopy during pregnancy

Although gastrointestinal endoscopy is generally safe, its safety must be separately analyzed during pregnancy with regard to fetal safety. Fetal risks from endoscopic medications are minimized by avoiding FDA category D drugs, minimizing endoscopic medications, and anesthesiologist attendance at endoscopy. Esophagogastroduodenoscopy seems to be relatively safe for the fetus and may be performed when strongly indicated during pregnancy. Despite limited clinical data, endoscopic banding of esophageal varices and endoscopic hemostasis of nonvariceal upper gastrointestinal bleeding seems justifiable during pregnancy. Flexible sigmoidoscopy during pregnancy also appears to be relatively safe for the fetus and may be performed when strongly indicated. Colonoscopy may be considered in pregnant patients during the second trimester if there is a strong indication. Data on colonoscopy during the other trimesters are limited. Therapeutic endoscopic retrograde cholangiopancreatography seems to be relatively safe during pregnancy and should be performed for strong indications (for example, complicated choledocholithiasis). Endoscopic safety precautions during pregnancy include the performance of endoscopy in hospital by an expert endoscopist and only when strongly indicated, deferral of endoscopy to the second trimester whenever possible, and obstetric consultation.

Pain relief in labor: a survey of awareness, attitude, and practice of health care providers in Zaria, Nigeria

Background:

The purpose of this study was to assess the attitudes of maternal health care providers to pain relief during labor in Zaria, Nigeria.

Methods:

This was a multicenter, collaborative, cross-sectional pilot study of provider perspectives concerning pain relief during labor. A structured, self-administered, questionnaire was completed by 95 consenting maternal health care providers at three high-volume facilities in Zaria, an ancient northern Nigerian city. Descriptive statistics was performed on the data.

Results:

Most respondents (94.8%) agreed that pain relief is needed during labor. Only 2.1% of respondents were undecided about the provision of pain relief during labor and 3.2% were of the opinion that pain relief was not necessary during labor. Most respondents (93.7%) had attended a woman in labor in the 4 weeks preceding the survey. Of these, 56.8% had counseled a parturient in labor. Most of the counseling (42.1%) took place during labor. Less than half of the respondents (48.4%) had administered pain relief in labor in the preceding 4 weeks and systemic opioids was the most commonly form of pain relief. Among the respondents who did not offer pain relief agents in labor, the majority (54.5%) had no reason for not offering it. Unavailability of methods, inability to afford the cost of pain relief, lack of knowledge and skills, as well as lack of essential equipment to provide the procedure were also given by respondents as reasons for not offering pain relief.

Conclusion:

Even though maternal health care providers in this environment have a positive attitude to pain relief in labor, most women go through labor without the benefit of analgesia. There exists a gap between provider attitudes to pain relief in labor and practice of the same, with many providers having no genuine reason(s) for not offering pain relief to their clients during labor. Providers need to align their practice to their attitudes, and need to be helped to do this through training as well as enhancing their ability to think critically about their practice.

The IDvIP trial: a two-centre randomised double-blind controlled trial comparing intramuscular diamorphine and intramuscular pethidine for labour analgesia

Background

Intramuscular pethidine is routinely used throughout the UK for labour analgesia. Studies have suggested that pethidine provides little pain relief in labour and has a number of side effects affecting mother and neonate. It can cause nausea, vomiting and dysphoria in mothers and can cause reduced fetal heart rate variability and accelerations. Neonatal effects include respiratory depression and impaired feeding. There are few large studies comparing the relative side effects and efficacy of different opioids in labour. A small trial comparing intramuscular pethidine with diamorphine, showed diamorphine to have some benefits over pethidine when used for labour analgesia but the study did not investigate the adverse effects of either opioid.

Methods

The Intramuscular Diamorphine versus Intramuscular Pethidine (IDvIP) trial is a randomised double-blind two centre controlled trial comparing intramuscular diamorphine and pethidine regarding their analgesic efficacy in labour and their side effects in mother, fetus and neonate. Information about the trial will be provided to women in the antenatal period or in early labour. Consent and recruitment to the trial will be obtained when the mother requests opioid analgesia. The sample size requirement is 406 women with data on primary outcomes. The maternal primary outcomes are pain relief during the first 3 hours after trial analgesia and specifically pain relief after 60 minutes. The neonatal primary outcomes are need for resuscitation and Apgar Score <7 at 1 minute. The secondary outcomes are an additional measure of pain relief, maternal sedation, nausea and vomiting, maternal oxygen saturation, satisfaction with analgesia, whether method of analgesia would be used again, use of Entonox, umbilical arterial and venous pH, fetal heart rate, meconium staining, time from delivery to first breath, Apgar scores at 5 mins, naloxone requirement, transfer to neonatal intensive care unit, neonatal haemoglobin oxygen saturation at 30, 60, 90, and 120 mins after delivery, and neonatal sedation and feeding behaviour during first 2 hours.

Discussion

If the trial demonstrates that diamorphine provides better analgesia with fewer side effects in mother and neonate this could lead to a change in national practice and result in diamorphine becoming the preferred intramuscular opioid for analgesia in labour.

Trial Registration

ISRCTN14898678

Eudra No: 2006-003250-18, REC Reference No: 06/Q1702/95, MHRA Authorisation No: 1443/0001/001-0001, NIHR UKCRN reference 6895, RfPB grant PB-PG-0407-13170_IR5

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 management of breakthrough pain during labour

There is a long history of attempts to alleviate the pain of childbirth, particularly in Asian and Middle Eastern civilisations. In the UK, it was the administration of chloroform to Queen Victoria by John Snow in 1853 that is widely credited with popularizing the idea that labour pain should and could be treated. Medical analgesia is now well established around the globe with a wealth of research evidence describing methods, efficacy and complications. In this article, we define 'primary breakthrough pain' as the moment when a woman first requests analgesia during labour. The management of this can include simple emotional support, inhaled analgesics, parenteral opioids and epidural analgesia. 'Secondary breakthrough pain' can be defined as the moment when previously used analgesia becomes ineffective. We concentrate our discussion of this phenomenon on the situation when epidural analgesia begins to fail. Only epidural analgesia offers the potential for complete analgesia, so when this effect is lost the recipient can experience significant distress and dissatisfaction. The best strategy to avert this problem is prevention by using the best techniques for epidural catheterisation and the most effective drug combinations. Even then, epidurals can lose their efficacy for a variety of reasons, and management is hampered by the fact that each rescue manoeuvre takes about 30 minutes to be effective. If the rescue protocol is too cautious, analgesia may not be successfully restored before delivery, leading to patient dissatisfaction. We therefore propose an aggressive response to epidural breakthrough pain using appropriate drug supplementation and, if necessary, the placement of a new epidural catheter. Combined spinal epidural techniques offer several advantages in this situation. The goal is to re-establish analgesia within 1 hour. The primary aim of pain management during labour and delivery is to provide the level of comfort determined as acceptable to each individual woman. Some require little or no analgesia, while others demand complete abolition of pain. Whatever the individual's personal point of breakthrough pain is, supporting clinicians should respond logically and rapidly to re-establish analgesia using locally agreed protocols. This approach will maximize patient satisfaction and hopefully increase the pleasure and satisfaction of childbirth.

Prescribing intramuscular opioids for labour analgesia in consultant-led maternity units: a survey of UK practice

BACKGROUND

Intramuscular opioids are widely used for analgesia in labour. We conducted a postal survey to establish current prescribing and monitoring guidelines for intramuscular opioids in consultant-led obstetric units in the UK.

METHODS

A postal questionnaire was sent between December 2005 and January 2006 to the lead obstetric anaesthetist of all 234 consultant-led obstetric units in the UK. We enquired about dose regimens of intramuscular opioids in labour and monitoring of mother, fetus and neonate.

RESULTS

The response rate was 71%; 84.4% of responding units used pethidine and 34.1% diamorphine. Meptazinol and morphine were available in 13.8% and 13.2% of units respectively. Some units used more than one opioid. The choice of opioid was dictated mainly by tradition (65.3%) and familiarity (40.7%). Prophylactic antiemetics were co-administered in 73.7% of units, the most commonly used being prochlorperazine (30.5%). Vital signs were monitored in 91.6% of units: in total 10.2% measured haemoglobin oxygen saturations and 4.8% respiratory rate. Pain scores were recorded in 13.7% of units.

CONCLUSIONS

When compared with previous studies the use of intramuscular diamorphine is increasing in UK consultant-led obstetric units, although pethidine remains the widely used opioid. At present this change cannot be justified by a suitably powered, randomised study comparing intramuscular pethidine with diamorphine.

Intravenous patient-controlled analgesia for labour: a survey of UK practice

BACKGROUND

Although regional techniques offer superior analgesia during labour, many women receive other methods of pain relief. Furthermore, there is a specific need for analgesia in a small population of labouring women for whom regional techniques are contraindicated, unavailable or impossible to perform. We surveyed current UK practice of labour analgesia for such patients, with particular reference to the use of intravenous patient-controlled analgesia.

METHODS

Following approval from the Obstetric Anaesthetists' Association, a questionnaire was sent to the lead anaesthetic consultants of 243 obstetric units in the United Kingdom. The questionnaire evaluated the availability of methods of pain relief other than regional blocks. Information was sought on patient-controlled intravenous analgesia regimens and patient monitoring.

RESULTS

A total of 159 questionnaires were returned giving a response rate of 65.4%. The majority of units that responded (95.5%) used either intramuscular pethidine or diamorphine. Nearly half (49%) offered patient-controlled intravenous analgesia for labour pain. One third of units (36%) had an analgesic protocol for women in whom regional anaesthetic techniques were contraindicated. With patient-controlled intravenous analgesia, remifentanil (34.6%) was the most commonly used opioid for live births while morphine (35.5%) was used more commonly for deliveries involving intrauterine deaths.

CONCLUSION

The survey demonstrated that, when regional techniques were contraindicated, patient-controlled intravenous opioid analgesia was employed in almost half of the units responding to the questionnaire.

Umbilical cord plasma concentrations of free morphine following single-dose diamorphine analgesia and their relationship to dose-delivery time interval, Apgar scores and neonatal respiration

OBJECTIVE

To find the effect of dose-delivery interval on cord-blood levels of diamorphine metabolites and its effect on Apgar sores and neonatal respiration.

STUDY DESIGN

Pilot study conducted in labour ward of a district general hospital. One hundred women who had normal delivery and received single dose of 7.5mg of intramuscular injection of diamorphine in labour were recruited in the study. A 2.0 ml sample of umbilical venous blood was collected from the placenta after delivery of the baby. The sample was analysed using RIA method to measure free morphine. Details about the labour and baby's condition at birth were recorded.

RESULTS

The concentration of free morphine in the umbilical venous blood was significantly associated with the dose-delivery interval (coefficient (95% CI)=1.08(0.99-1.18), p<0.001). Twenty neonates had low Apgar score (< or =7) at 1 min. The odds of such a low score were raised with higher log free morphine in the cord venous plasma, but not statistically significantly (OR (95% CI)=5.3 (0.84-34), p=0.08). Fourteen neonates required resuscitation. The odds of requiring resuscitation were significantly raised with higher log free morphine: OR (95% CI)=9.3 (1.0-86), p=0.05.

CONCLUSION

Concentration of free morphine in the umbilical venous blood after delivery was significantly associated with the dose-delivery interval and this had significant effect on the need for resuscitation.

American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy

This literature review and the recommendations therein were prepared for the American Gastroenterological Association Institute Clinical Practice and Economics Committee. The paper was approved by the Committee on February 22, 2006 and by the AGA Institute Governing Board on April 20, 2006.

Sedation and analgesia for gastrointestinal endoscopy during pregnancy

Endoscopy during pregnancy raises the unique issue of fetal safety. Endoscopic medications comprise a significant component of fetal risks from endoscopy. Before endoscopy, the gastroenterologist or anesthesiologist should evaluate the potential fetal risks of sedation and analgesia, identify any contraindications to endoscopy, stabilize the maternal medical status as necessary, and correct maternal hypoxia or hypotension. The mother should be informed about the potential teratogenic risks of endoscopic medications during pregnancy. Patients who receive sedation and analgesia should be monitored during endoscopy by continuous electrocardiography, continuous pulse oximetry, and intermittent sphygmomanometry, as well as by the pulse and respiratory rate. General principles of sedation and analgesia during pregnancy include use of the minimal effective dose, avoidance of unnecessary medications, and preferable use of Food and Drug Administration category B medications.

Diamorphine for pain relief in labour : a randomised controlled trial comparing intramuscular injection and patient-controlled analgesia

OBJECTIVES

To compare the efficacy of diamorphine administered by a patient-controlled pump (patient-controlled analgesia) with intramuscular administration for pain relief in labour.

DESIGN

Randomised controlled trial.

SETTING

The South Glasgow University Hospitals NHS Trust.

SAMPLE

Primigravidae and multigravidae in labour at term (37-42 weeks).

METHODS

Women were randomised in labour to the study (patient-controlled analgesia) or control group (intramuscular). Randomisation was achieved through a random permuted block design stratified by parity. Study group women were given a loading dose of 1.2 mg diamorphine intravenously and then attached to the pump. Control group women received intramuscular diamorphine as per hospital protocol. Participants were also given 3 mg of buccal Stemetil. Data were collected throughout labour and at six postnatal weeks.

MAIN OUTCOME MEASURES

Analgesia requirements during labour and women's satisfaction with the method of pain relief.

RESULTS

Women in the study group (patient-controlled analgesia) used significantly less diamorphine than women in the control group (intramuscular) but were significantly more likely to state that they were very dissatisfied with their use of diamorphine and were significantly more likely to opt out of the trial before the birth of the baby. The majority of women in both groups used other analgesia concurrent with diamorphine such as Entonox, aromatherapy or TENS.

CONCLUSIONS

Patient-controlled analgesia administration of diamorphine for the relief of pain in labour offers no significant advantages over intramuscular administration. The results also suggest that diamorphine is a poor analgesic for labour pain irrespective of the mode of administration.

A double blinded randomised placebo-controlled study of intramuscular pethidine for pain relief in the first stage of labour

OBJECTIVE

It has recently been suggested that systemic pethidine is ineffective in relieving labour pain. This study aims to evaluate the analgesic efficacy of pethidine in labour.

DESIGN

This is a double blinded randomised placebo-controlled study.

SETTING

Labour suite, Prince of Wales Hospital, Hong Kong. Population Fifty normal Chinese pregnant women in early labour.

METHODS

We planned to randomise 112 women in early labour to receive either intramuscular pethidine 100 mg or normal saline when they requested analgesia. An interim analysis was performed at sample size 50.

MAIN OUTCOME MEASURES

The primary outcome assessed was the visual analogue scale (VAS) pain score after 30 minutes.

RESULTS

The study was terminated after recruitment of the first 50 women when planned interim analysis showed a significantly greater reduction of VAS pain score in the pethidine group (P= 0.009). The median difference in VAS pain score between the two groups at 30 minutes was -17 [95% CI -30 to -4]. Mean time to first subsequent request for analgesia was greater in the pethidine group (232 minutes, 95% CI 135 to 329 minutes) compared with the control group (75 minutes, 95% CI 54 to 95 minutes). Eight women (32%) in the pethidine group needed no further analgesia vs one woman (4%) in the control group (P= 0.011). Women in the pethidine group gave greater scores for sedation and satisfaction. Neonatal outcome was similar.

CONCLUSIONS

Systemic pethidine was more effective at relieving labour pain than placebo. Its analgesic effect, however, was modest.

The fetal safety and clinical efficacy of gastrointestinal endoscopy during pregnancy

More than 12,000 pregnant patients in the United States per annum have conditions that are normally evaluated by EGD. More than 6000 pregnant patients in the United States per annum have conditions that are normally evaluated by sigmoidoscopy or colonoscopy. About one thousand more have symptomatic choledocholithiasis during pregnancy, which is a strong indication for endoscopic sphincterotomy in nonpregnant patients. Endoscopy during pregnancy raises the unique issue of fetal safety. Endoscopic medications comprise a significant component of fetal endoscopic risks. Safety of EGD during pregnancy has been examined in a case-controlled study of 83 patients, a mailed survey of 73 patients, and 28 case reports. Safety of sigmoidoscopy during pregnancy has been examined in a case-controlled study of 46 patients, a mailed survey of 13 patients, and 10 case reports. Safety of therapeutic ERCP during pregnancy has been analyzed in studies of 23, 10, 6, and 5 patients, and in 32 case reports. These studies suggested that EGD, sigmoidoscopy, and ERCP should be performed when strongly indicated: EGD for significant upper gastrointestinal bleeding, sigmoidoscopy for nonhemorrhoidal rectal bleeding, and ERCP for symptomatic choledocholithiasis when sphincterotomy is contemplated. PEG and colonoscopy are currently considered experimental during pregnancy because of insufficient data on fetal safety. Several cases of PEG and colonoscopy were successfully performed during pregnancy. Performance of endoscopy during pregnancy should increase with further technical refinements, and greater awareness of procedure safety.

Meperidine: a critical review

Meperidine was initially synthesized as an anticholinergic agent but was soon discovered to have analgesic properties. Although meperidine's anticholinergic effects were demonstrated in vivo, the anticholinergic effects on the biliary and renal tracts have not been demonstrated in vivo. Studies have clearly demonstrated that meperidine is no more efficacious in treating biliary or renal tract spasm than comparative mu opioids. The initial studies demonstrating the analgesic efficacy of meperidine were mostly case reports and not double-blind, randomized, controlled trials in specific populations. Subsequent comparative studies failed to demonstrate any advantages of meperidine over comparable doses of other analgesics. Meperidine was portrayed in practice and teaching as having unique clinical advantages. The analgesic effects of meperidine are not pronounced, and, in addition, meperidine use is complicated by unique side effects including serotonergic crisis and normeperidine toxicity. Meperidine's poor efficacy, toxicity, and multiple drug interactions have resulted in a movement to replace meperidine with more efficacious and less toxic opioid analgesics.

Effects of a kappa agonist, spiradoline mesylate (U62,066E), on activation and vaginocervical-stimulation produced analgesia in rats

Previous research has demonstrated increased pain threshold during copulation, gestation, and parturition in animals. In the laboratory, mechanostimulation of the vaginocervical region in many animals, as well as humans, can increase responsiveness to noxious but not to innocuous stimuli. This increased pain inhibition to vaginocervical stimulation, which mimics natural parturition, is mediated by spinal and supraspinal neuropeptides, including the opiates. The present research was designed to ascertain the possible effects of a kappa opioid agonist on vaginocervical-stimulated analgesia in rats. Initially, the novel kappa-selective agonist, spiradoline mesylate (U62,066E; 0, 0.1, 1.0, 10.0 mg/kg, i.p.), was injected intraperitoneally and general behavioral arousal in an open field apparatus was recorded. Results from this experiment indicate that stimulation with the kappa-selective drug caused significant decreases in behavioral activity at the high dose as compared to saline and the medium and low doses. Next, the effects of U62,066E (0, 0.1, 1.0, 10.0 mg/kg, i.p.) on the analgesia associated with vaginocervical stimulation were determined in a tail flick apparatus. The kappa drug significantly increased antinociceptive thresholds prior to and during vaginocervical stimulation at the 0.1 and 1.0 mg/kg doses. By contrast, the high dose (10.0 mg/kg) of U62,066E decreased vaginocervical stimulation-produced analgesia. Results are discussed in terms of the potential of nonaddictive kappa-selective opioid compounds being utilized in reproductive pain.