Intravenous paracetamol infusion versus intramuscular tramadol as an intrapartum labor analgesic

Tools for assessing labour pain: a comprehensive review of research literature

ABSTRACT

The experience of pain associated with labour is complex and challenging to assess. A range of pain measurement tools are reported in the literature. This review aimed to identify current tools used in research to assess labour pain across the past decade and to evaluate their implementation and adequacy when used in the context of labour pain. A literature search was conducted in databases MEDLINE and Cumulative Index of Nursing and Allied Health Literature, using search terms relating to labour, pain, and measurement. A total of 363 articles were selected for inclusion. Most studies (89.9%) assessed pain as a unidimensional experience, with the most common tool being the Visual Analogue Scale, followed by the Numerical Rating Scale. Where studies assessed pain as a multidimensional experience, the most common measurement tool was the McGill Pain Questionnaire. Only 4 studies that used multidimensional tools selected a tool that was capable of capturing positive affective states. Numerous variations in the implementation of scales were noted. This included 35 variations found in the wording of the upper and lower anchors of the Visual Analogue Scale, some assessment tools not allowing an option for "no pain," and instances where only sections of validated tools were used. It is clear that development of a standardised pain assessment strategy, which evaluates the multidimensions of labour pain efficiently and effectively and allows for both positive and negative experiences of pain to be reported, is needed.

Comparison of intravenous paracetamol infusion versus intramuscular tramadol as labor analgesia: a randomized control trial

PURPOSE

Labor pain is one of the most agonizing pains experienced by all delivered women. Many pharmacological agents used in labor analgesia require intense monitoring facilities, which are not available in routine obstetric practice in low-resource settings. This study aimed to compare the efficacy of intravenous (IV) paracetamol and intramuscular (IM) tramadol on labor pain relief, labor progression, and maternal and neonatal outcomes.

METHODS

This randomized drug trial was carried out on 110 women divided into two groups. Group A women received 1000 mg of IV paracetamol, and Group B women received 100 mg of IM tramadol during the active phase of labor. Pain intensity was assessed by the Visual Analogue Scale (VAS) at intervals till 120 min of delivery. The maternal and neonatal outcomes were recorded.

RESULTS

There was a statistically significant fall in pain score till 180 min of drug administration in the paracetamol group and 120 min in the tramadol group. At 180 min and 240 min, paracetamol is more effective than tramadol (p value 0.004 at 180 min and 0.0119 at 240 min). There were significantly low pain score levels at 60 min of delivery in the paracetamol group (p value-0.004). Nausea and vomiting were significantly higher in the tramadol group (p value 0.000013).

CONCLUSION

Compared to IM tramadol, IV paracetamol has a longer duration of action and fewer maternal side effects, making it suitable for parenteral analgesia in labor. Due to a better safety profile, there is no need for intense maternal and fetal monitoring with IV paracetamol.

TRIAL REGISTRATION

Clinical Trials Registry-India (CTRI registration number-CTRI /2019/05/019244).

Oral acetaminophen as an adjunct to continuous epidural infusion and patient-controlled epidural analgesia in laboring parturients: a randomized controlled trial

BACKGROUND

Intravenous acetaminophen is safe and effective as an adjunct to labor analgesia with combined spinal-epidural (CSE) analgesia and patient-controlled epidural analgesia (PCEA). Oral acetaminophen is a much cheaper and safe option but has not been studied as an adjunct to labor analgesia till date. The aim of the present study is to evaluate the effect of oral acetaminophen as an adjunct in patients receiving local anesthetic-opioid combination using CSE analgesia.

METHOD

In this ethically approved randomized double-blind placebo-controlled trial, 60 consenting parturients were randomly allocated to two groups of 30 each: acetaminophen (who received oral acetaminophen 1 g) or placebo, 45 min before the procedure. CSE was administered as per hospital protocol. All the patients received continuous epidural infusion (CEI) of levobupivacaine 0.1% and fentanyl 2 mcg/mL at 5 ml/h and PCEA boluses of 5 mL of the same drug with a lockout interval of 15 min if needed. The primary outcome was hourly mean consumption of levobupivacaine and fentanyl mixture (mL/h). Secondary outcomes included pain score, sensory and motor block, hemodynamic parameters of mother, duration of the second stage of labor, mode of delivery, maternal satisfaction, Apgar scores, fetal heart rate, and adverse effects.

RESULTS

The mean drug consumption per hour was significantly less in the acetaminophen group than in the placebo group (7.66 mL/h, SD 2.01 vs. 9.01 mL/h, SD 2.83; p = 0.04). The requirement for bolus was also significantly less in the acetaminophen group than in the placebo group (median 2.5, IQR 3 vs. median 3.5, IQR 2; p = 0.04).

CONCLUSION

The use of 1 g of oral acetaminophen could be a cheap, safe, and effective adjunct to CEI plus PCEA in labor analgesia.

Efficacy and safety of intravenous paracetamol in management of labour pains in a low resource setting: a randomized clinical trial

OBJECTIVE

To assess the use of single dose of paracetamol intravenously in management of labour pains.

BACKGROUND

Pain during labour is a complex, subjective and multi-faceted physiological phenomenon that varies in intensity among women and is subjected to many social and cultural modifiers.

SUBJECTS AND METHODS

This randomized clinical study was conducted in Obstetrics and gynecology department from March 2019 to March 2020 including 96 primiparous women randomized into paracetamol group (n = 48) received 1000 mg of paracetamol IV infusion and pethidine group (n = 48) received 50 mg of pethidine given slowly IV. Primary outcome is the change of the intensity of perceived labor pain. Pain score was followed and recorded by visual analogue scale (VAS). Our study protocol was registered at ClinicalTrials.gov; NCT04744727.

RESULTS

VAS score was highly significant improved gradually after 30 min, 1, 2 and 3 h of paracetamol and pethidine taken compared at start study, but participants in paracetamol group had lower pain after 2 and 3 h (3.92 ± 1.42 and 5.69 ± 1.07) than those of the pethidine groups (4.42 ± 1.87 and 5.38 ± 1.34). Also, 2.1% of paracetamol group developed dizziness and 4.2% developed nausea and vomiting, while there was 29.2% of pethidine group developed dizziness and 37.5% developed nausea and vomiting.

CONCLUSIONS

Intravenous paracetamol as labour analgesia is effective, safe, inexpensive, available and with no maternal or fetal side effects as compared to Pethidine. Paracetamol needs to have more chance in comparison to other forms as a labour pain analgesia, especially in our communities.

Comparison of Pain Score and Complications Following Acetaminophen and Pethidine Injection During Vaginal Delivery: A Double-blind Clinical Trial

Objectives

Recently, intravenous acetaminophen has been introduced as an intervention with analgesic potential similar to that of opioid analgesics in labor pain management. This study aimed to compare the pain score and maternal and neonatal complications following acetaminophen and pethidine injections during vaginal delivery.

Methods

This randomized, double-blind clinical trial was conducted on pregnant women during the first stage of delivery referred to Ghaem and Omolbanin Hospitals in Mashhad, Iran, from March to December 2017. The subjects were assigned randomly to one of two groups: acetaminophen and pethidine. The pain intensity was measured before and 15, 60, 120, 180, and 240 minutes after injection.

Results

The pain score and pain score changes showed no significant difference between the two groups at different times. The incidence of maternal complications during delivery and the first hour after delivery was not statistically significant between the two groups, but 15 minutes after injection, vomiting (p = 0.001), nausea (p = 0.001), and dizziness (p = 0.001) were significantly higher in the pethidine group. The mean one and five minutes Apgar scores were significantly higher in the acetaminophen group.

Conclusions

Intravenous acetaminophen led to fewer maternal complications than pethidine, especially during the first 15 minutes after injection and fewer neonatal complications, especially in the Apgar score.

[Normal childbirth: physiologic labor support and medical procedures. Guidelines of the French National Authority for Health (HAS) with the collaboration of the French College of Gynaecologists and Obstetricians (CNGOF) and the French College of Midwives (CNSF) - Mother's wellbeing and regional or systemic analgesia for labor]

INTRODUCTION

These guidelines deal with the parturient wellbeing in terms of hydration and regional and systemic pain management during labour.

METHOD

Guidelines were established based on literature analysis and experts consensus.

RESULTS

Clear liquids consumption is permitted all along labor and postpartum, without volume limitation, in patients at low risk of general anesthesia (grade B). The consumption of solid foods is not recommended during the active stage of labor (consensus agreement). It is recommended to promote on regional analgesia to prevent inhalation (grade A). Pain relief using regional analgesia is a part of normal childbirth. It is recommended to provide regional analgesia to parturient who wish these technics. Regional analgesia is the safest and most effective analgesic method for the mother (grade A) and the child (grade B). It is recommended to inform women on the analgesic technics, to respect their choice and consider the right for a parturient to change her strategy in obstetrical circumstances or in cases of untractable pain (consensus agreement). It is recommended to perform a "low-dose" regional analgesia that respects the experience of childbirth (grade A) and maintain it with a patient controlled epidural analgesia technics (grade A). There is no minimum cervical dilation to allow epidural analgesia (grade A). In cases of rapid labor or after delivery for revision, spinal or combined spinal epidural can be used (grade C). Epidural has not to be ended before birth (consensus agreement). Blood pressure and fetal heart rate must be monitored every 3minutes after induction and/or each 10mL bolus then hourly (consensus agreement). Systematic and preventive fluid loading is not needed if only due to regional analgesia (grade B). Deambulation or postures are allowed in the absence of motor block and must be traced and do not alter the distribution of the regional analgesia (grade C). The postures of childbirth do not alter regional analgesia spread (NP2). There is no effect low dose regional analgesia on the duration of obstetric labor, nor the rate of instrumental births or caesarean section (NP1). Systematic use of oxytocin due to epidural analgesia is neither useful nor recommended (AE). Regional analgesia has no side effect on the fetus or newborn (NP1). If regional analgesia is contraindicated or during the waiting time, alternatives analgesic drugs (entonox, nalbuphine and tramadol or pudendal block) can be used but their analgesic efficiency remains mediocre to moderate and they are associated with adverse maternal and especially neonatal side effects (NP2). Remifentanil, ketamine and volatile anesthetics are excluded from these recommendations.

CONCLUSION

The present guidelines were established to update wellbeing of normal parturient during normal labor: hydration is recommended and low dose patient-controlled regional (epidural and spinal) analgesia is the most effective and safest analgesic method.

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.

Efficacy of Intravenous Infusion of Acetaminophen for Intrapartum Analgesia

INTRODUCTION

The intensity of pain experienced by women in labour, has been found to affect the progress of labour, foetal well-being and maternal psychology. Adverse effects associated with commonly used opioids for providing intrapartum analgesia have created a need for an alternative non-opioid drug.

AIM

To evaluate the efficacy of an intravenous infusion of 1000 mg of acetaminophen as an intrapartum analgesic.

MATERIALS AND METHODS

The present prospective single-centre, single blind, placebo-controlled randomized interventional study was conducted in Department of Obstetrics and Gynaecology in Vardhaman Mahavir Medical College & Safdarjung Hospital over a period of six months from September 2014 to March 2015. After receiving the ethical clearance and written informed consent. The first 200 consecutive parturients fulfilling the inclusion criteria were recruited into the study. Women were then randomised to receive either intravenous 1000 mg (100ml) of acetaminophen (Group A, n=100) or 100 ml normal saline (Group B, n=100). Primary outcome assessed was effectiveness of acetaminophen to provide an adequate amount of analgesia, as measured by a change in Visual Analogue Scale (VAS) pain intensity score at various times after drug administration. Secondary outcomes measured were duration of labour, need for additional rescue analgesia and presence of adverse maternal or foetal effect.

RESULTS

There was pain reduction at 1 and 2 hours in both groups (p<0.001). However, it was more significant in the acetaminophen group, especially at 1 hour. Duration of labour was shortened in both the groups, without any maternal and foetal adverse effects.

CONCLUSION

Intravenous acetaminophen is an efficacious non-opioid drug for relieving labour pain without any significant maternal and foetal adverse effects.