Lumbar sympathetic blocks speed early and second stage induced labor in nulliparous women

Effect of epidural analgesia on cervical ripening using dinoprostone vaginal inserts

OBJECTIVE

To clarify whether the duration from cervical ripening induction to labor onset is prolonged when epidural analgesia is administered following application of dinoprostone vaginal inserts vs. cervical ripening balloon.

METHODS

This retrospective study included mothers with singleton deliveries at a single center between 2020-2021. Nulliparous women who underwent labor induction and requested epidural analgesia during labor after 37 weeks of gestation were included. The duration from cervical ripening induction to labor onset was compared between women using a dinoprostone vaginal insert and those using a cervical ripening balloon and between women who received epidural analgesia before and after labor onset.

RESULTS

In the dinoprostone vaginal insert group, the duration was significantly shorter in the subgroup that received epidural analgesia after labor onset (estimated median, 545 [95% confidence interval: 229-861 min]) than the subgroup that received it before labor onset (estimated median, 1,570 [95% confidence interval: 1,226-1,914] min, p = 0.004). However, in the cervical ripening balloon group, the difference between subgroups was not significant. The length of labor among the groups was also not significantly different.

CONCLUSION

Epidural analgesia as labor relaxant adversely affected the progression of uterine cervical ripening when dinoprostone vaginal inserts were used, whereas it did not affect cervical ripening when a mechanical cervical dilatation balloon was used. The present results are significant for choosing the appropriate ripening method.

Regional anaesthesia for labour, operative vaginal delivery and caesarean delivery: a narrative review

This narrative review discusses recent evidence surrounding the use of regional anaesthesia in the obstetric setting, including intrapartum techniques for labour and operative vaginal delivery, and caesarean delivery. Pudendal nerve blockade, ideally administered by an obstetrician, should be considered for operative vaginal delivery if neuraxial analgesia is contraindicated. Regional techniques are increasingly utilised in clinical practice for caesarean delivery to minimise opioid consumption, reduce pain, improve postpartum recovery and facilitate earlier discharge as part of enhanced recovery protocols. The evidence surrounding transversus abdominis plane and quadratus lumborum blockade supports their use when: long-acting neuraxial opioids cannot be administered due to contraindications; if emergency delivery necessitates general anaesthesia; or as a postoperative rescue technique. Current data suggest quadratus lumborum blockade is no more effective than transversus abdominis plane blockade after caesarean delivery. Transversus abdominis plane blockade, wound catheter insertion and single shot wound infiltration are all effective techniques for reducing postoperative opioid consumption, with transversus abdominis plane blockade favoured, followed by wound catheters and then wound infiltration. Ilio-inguinal and iliohypogastric, erector spinae plane and rectus sheath blockade all require further studies to determine their efficacy for caesarean delivery in the presence or absence of long-acting neuraxial opioids. Future studies are needed to: compare approaches for individual techniques; determine which combinations of techniques and dosing regimens result in optimal analgesic and recovery outcomes following delivery; and elucidate the populations that benefit most from regional anaesthesia in the obstetric setting.

Comparison of the labor curves with and without combined spinal-epidural analgesia in nulliparous women- a retrospective study

Background

Neuraxial labor analgesia is known to increase the rate of instrumental delivery and prolong the second stage of labor; however, there is no standard method to evaluate the progress of labor under analgesia. Friedman curve is considered the gold standard for evaluating the progress of labor. However, it included not only neuraxial labor analgesia but also labor without analgesia. Thus we compared the labor curves of primiparous women undergoing labor with and without neuraxial labor analgesia, to understand the progress of labor in both groups and to arrive at a standard curve to monitor the progress of labor under neuraxial analgesia.

Methods

Primiparous women with cephalic singleton pregnancies who delivered at term from 2016 to 2017 were included. Two hundred patients who opted for combined spinal-epidural (CSE) labor analgesia were included in the CSE group and 200 patients who did not undergo CSE were included in the non-CSE group. In all, 400 cases were examined retrospectively. The evaluation parameters were cervical dilation and fetal station, and we calculated the average value per hour to plot the labor curves.

Results

The labor curve of the non-CSE group was significantly different from the Friedman curve. In the CSE group, the time from 4 cm dilation of the cervix to full dilation was 15 h; in addition, the speed of cervical dilation was different from that in the non-CSE group. The progress of labor in the CSE group was faster than that in the non-CSE group during the latent phase; however, the progress in the CSE group was slower than that in the non-CSE group during the active phase.

Conclusions

Neuraxial labor analgesia results in early cervical dilation and descent of the fetal head; thus, appropriate advance planning to manage the delivery may be essential.

Analgesia for childbirth: modern insights into an age-old challenge and the quest for an ideal approach

SUMMARY It is widely recognized that childbirth may be the most painful experience in a woman’s lifetime and that women have a right to relief. There are many options, but the efficacy of only a few is supported by robust evidence. Many influences determine which method of pain relief is chosen, including social and cultural factors, availability, cost and personal preference. Due to human diversity and the differing perspectives of consumers, obstetric care providers and health administrators, there is no such thing as ‘an ideal approach’. In resource-rich societies, major advances in parturient safety and outcome flow from technique development and better monitoring. Greater awareness of the negative impact of untreated pain and of the relevance of genetic, cultural and social factors motivates research into better predictive models, novel therapies and optimization of existing methods.

Paravertebral blocks

PVB remains an underused block. It is easy to perform reliable and effective blocks for a wide variety of applications both for acute or chronic pain. As evidence continues to be published showing the advantages of PVB versus traditional methods of pain control, it is hoped that PVB will become part of the standard repertoire of blocks used in teaching hospitals and in private practice.

Local anaesthetic nerve block for pain management in labour

BACKGROUND

Local anaesthetic nerve block is an important modality for pain management in labour. Pudendal and paracervical block (PCB) are most commonly performed local anaesthetic nerve blocks which have been used for decades.

OBJECTIVES

To establish the efficacy and safety of local anaesthetic nerve blocks for pain relief in labour.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2012).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) assessing pain management in labour with the use of local anaesthetic nerve blocks. We did not include results from quasi-RCTs.

DATA COLLECTION AND ANALYSIS

We designed a form to extract data. For eligible studies, two review authors extracted the data using the agreed form. We resolved discrepancies through discussion or, if required, we consulted a third person. We entered and analysed data using Review Manager software and checked for accuracy.

MAIN RESULTS

We found 41 trials for consideration of inclusion into this review. We included only 12 RCTs (1549 participants) of unclear quality. We excluded 29 studies (30 reports). The majority of excluded studies were not relevant to this review, and a few were not randomised.Local anaesthetic nerve block versus placebo or no treatment. We found that more women were satisfied with pain relief after local anaesthetic nerve block (in particular 2% lidocaine PCB) than after placebo (one study, 198 participants, risk ratio (RR) 32.31, 95% confidence interval (CI) 10.60 to 98.54). Local anaesthetic nerve block was associated with more side effects (one study, 200 participants, RR 29.0, 95% CI 1.75 to 479.61).Local anaesthetic nerve block (in particular, PCB) versus opioid Local anaesthetic nerve block (in particular, PCB) in comparison with opioid (in particular, intramuscular pethidine or fentanyl patient-controlled analgesia) was found to be more effective for pain relief (one study, 109 participants, RR 2.52, 95% CI 1.65 to 3.83) and was not associated with an increased rate of assisted vaginal birth (two studies, 129 participants, RR 1.02, 95% CI 0.56 to 1.87) or with an increased caesarean section rate (two studies, 129 participants, RR 0.23, 95% CI 0.03 to 1.87).Local anaesthetic nerve block versus non-opioid agents Satisfaction with pain relief and rate of caesarean sections were found to be the same in women receiving local anaesthetic nerve block and non-opioid agents (one study, 100 participants, RR 1.11, 95% CI 0.67 to 1.84; RR 2.0, 95% CI 0.19 to 21.36, respectively). More women who received non-opioid agent in comparison with women who received local anaesthetic nerve block required additional interventions for pain relief (one study, 100 participants, RR 0.06, 95% CI 0.02 to 0.25).Local anaesthetic nerve block using different anaesthetic agents There was no difference in pain relief satisfaction, assisted vaginal birth, caesarean section, side effects for mother, Apgar score or admission to the neonatal intensive care unit between different anaesthetic agents, e.g. bupivacaine, carbocaine, lidocaine, chloroprocaine.

AUTHORS' CONCLUSIONS

Local anaesthetic nerve blocks are more effective than placebo, opioid and non-opioid analgesia for pain management in labour based on RCTs of unclear quality and limited numbers. Side effects are more common after local anaesthetic nerve blocks in comparison with placebo. Different local anaesthetic agents used for pain relief provide similar satisfaction with pain relief. Further high-quality studies are needed to confirm the findings, to assess other outcomes and to compare local anaesthetic nerve blocks with various modalities for pain relief in labour.

Advances in labor analgesia

The pain of childbirth is arguably the most severe pain most women will endure in their lifetimes. The pain of the early first stage of labor arises from dilation of the lower uterine segment and cervix. Pain from the late first stage and second stage of labor arises from descent of the fetus in the birth canal, resulting in distension and tearing of tissues in the vagina and perineum. An array of regional nerve blocks, systemic analgesic, and nonpharmacologic techniques are currently used for labor analgesia. Nonpharmacologic methods are commonly used, but the effectiveness of these techniques generally lacks rigorous scientific study. Continuous labor support has been shown to decrease the use of pharmacologic analgesia and shorten labor. Intradermal water injections decrease back labor pain. Neuraxial labor analgesia (most commonly epidural or combined spinal-epidural) is the most effective method of pain relief during childbirth, and the only method that provides complete analgesia without maternal or fetal sedation. Current techniques commonly combine a low dose of local anesthetic (bupivacaine or ropivacaine) with a lipid soluble opioid (fentanyl or sufentanil). Neuraxial analgesia does not increase the rate of cesarean delivery compared to systemic opioid analgesia; however, dense neuraxial analgesia may increase the risk of instrumental vaginal delivery.

Labor pain at the time of epidural analgesia and mode of delivery in nulliparous women presenting for an induction of labor

OBJECTIVE

To assess whether the degree of labor pain at the initiation of neuraxial analgesia is associated with mode of delivery.

METHODS

Nulliparous women who presented to the labor department for an induction of labor, who were between 37 and 41 weeks of gestation, and who requested labor epidural analgesia with a pain score of 0-3 (low pain) and a cervical dilatation less than 4 cm were assessed retrospectively. Maternal and neonatal outcome including mode of delivery and duration of labor were compared with a similar group of women with pain scores of 4-6 (moderate pain), and 7-10 (severe pain). Assessing whether there was an association between pain level at the time of epidural and operative delivery rates was analyzed using a chi test for trend and by logistic regression to include potentially relevant covariates.

RESULTS

We found 185 nulliparous women with low pain and compared them with a randomly selected equal number of women in each of the other pain groups. There was no significant association between pain groups in terms of duration of the first or second stage of labor or mode of delivery. Women with low pain had an operative delivery rate (instrumental assisted vaginal delivery plus cesarean delivery) of 49%, compared with 45% and 45% in those with moderate and severe pain, respectively (P=.40).

CONCLUSION

We did not find an association between the degree of labor pain at initiation of epidural analgesia and mode of delivery or duration of labor.

LEVEL OF EVIDENCE

II.

The risk of cesarean delivery with neuraxial analgesia given early versus late in labor

BACKGROUND

Epidural analgesia initiated early in labor (when the cervix is less than 4.0 cm dilated) has been associated with an increased risk of cesarean delivery. It is unclear, however, whether this increase in risk is due to the analgesia or is attributable to other factors.

METHODS

We conducted a randomized trial of 750 nulliparous women at term who were in spontaneous labor or had spontaneous rupture of the membranes and who had a cervical dilatation of less than 4.0 cm. Women were randomly assigned to receive intrathecal fentanyl or systemic hydromorphone at the first request for analgesia. Epidural analgesia was initiated in the intrathecal group at the second request for analgesia and in the systemic group at a cervical dilatation of 4.0 cm or greater or at the third request for analgesia. The primary outcome was the rate of cesarean delivery.

RESULTS

The rate of cesarean delivery was not significantly different between the groups (17.8 percent after intrathecal analgesia vs. 20.7 percent after systemic analgesia; 95 percent confidence interval for the difference, -9.0 to 3.0 percentage points; P=0.31). The median time from the initiation of analgesia to complete dilatation was significantly shorter after intrathecal analgesia than after systemic analgesia (295 minutes vs. 385 minutes, P<0.001), as was the time to vaginal delivery (398 minutes vs. 479 minutes, P<0.001). Pain scores after the first intervention were significantly lower after intrathecal analgesia than after systemic analgesia (2 vs. 6 on a 0-to-10 scale, P<0.001). The incidence of one-minute Apgar scores below 7 was significantly higher after systemic analgesia (24.0 percent vs. 16.7 percent, P=0.01).

CONCLUSIONS

Neuraxial analgesia in early labor did not increase the rate of cesarean delivery, and it provided better analgesia and resulted in a shorter duration of labor than systemic analgesia.

Newer techniques of labor analgesia

In maternity units in which central neuraxial techniques are frequently used, newer methods of epidural drug delivery (continuous infusion, patient-controlled) are well established and combined spinal-epidural analgesia is commonly used. Continuous spinal analgesia has reemerged as a useful approach after accidental dural puncture. Lumbar sympathetic block has been revisited and the safety of paracervical nerve block improved. The analgesic properties of systemic opioid in labor are poor, but PCIA at least has psychological benefits and allows rapid drug titration. PCIA is again under investigation because of the potent antinociceptive effects of the short-acting mu-opioid agonist, remifentanil. The premixing of nitrous oxide and a subanesthetic concentration of volatile anesthetic for patient-controlled administration has been tested under control of midwifery staff and without direct medical supervision.

Paravertebral anaesthesia/analgesia for ambulatory surgery

For many years, paravertebral nerve blockade has been an established technique for providing analgesia to the chest and abdomen. The current emphasis on containment of health care costs has resulted in a rediscovery of anaesthetic techniques, such as paravertebral blocks, that facilitate outpatient surgical management and promote early discharge. Paravertebral nerve blocks (PVB) produce excellent surgical conditions for many procedures of the chest and abdomen while providing profound long-lasting analgesia with few undesirable side-effects that aids in the compassionate early discharge of the patient from the ambulatory setting. This chapter reviews the pertinent anatomy and techniques involved in the successful placement of PVB. Continuous paravertebral catheters, pharmacological agents used in PVB, and single versus multiple injection paravertebral block techniques are also covered. Specific clinical situations that are particularly well suited to the application of PVB as the primary anaesthetic in the ambulatory setting and other clinical situations where analgesia from PVB is efficacious are discussed.

Epidural analgesia: effects on labor progress and maternal and neonatal outcome

The intended and unintended effects of epidural labor analgesia are reviewed. Mothers randomized to epidural rather than parenteral opioid analgesia have better pain relief. Fetal oxygenation is not affected by analgesic method; however, neonates whose mothers received intravenous or intramuscular opioids rather than epidural analgesia require more naloxone and have lower Apgar scores. Epidural analgesia does not affect the rates of cesarean delivery, obstetrically indicated instrumented vaginal delivery, neonatal sepsis, or new-onset back pain. Epidural analgesia is associated with longer second labor stages, more frequent oxytocin augmentation, and maternal fever (particularly among women who shiver and women receiving epidural analgesia for > 5 hours) but not with longer first labor stages. Epidural analgesia has no affect but intrapartum opioids decrease lactation success. Epidural use and urinary incontinence are weakly, but probably not causally, associated. Epidural labor analgesia would improve if the mechanisms of these unintended effects could be determined.

Combined spinal-epidural analgesia for labor: breakthrough or unjustified invasion?

The combined spina-epidural (CSE) technique has become increasingly popular for labor analgesia. The advantages of the CSE include more rapid onset of analgesia, reduced total drug dosage, minimal or no motor blockade, and increased patient satisfaction. CSE has also been associated with more rapid cervical dilation when compared to epidural analgesia in nulliparous women in early labor. Despite these potential advantages, the indications for CSE versus epidural analgesia remain unclear and controversial. This review should allow better understanding of the benefits and risks of this technique, and bearing in mind that no ultimate neuraxial analgesic exists, it would seem that CSE should be considered a major breakthrough in the management of labor analgesia.

Bilateral paravertebral block: a satisfactory alternative for labour analgesia

PURPOSE

To describe a new technique of paravertebral block for labour analgesia and to report the successful use of bilateral paravertebral block in four parturients with contraindications to conventional labour epidural analgesia.

CLINICAL FEATURES

Four parturients with contraindications to lumbar epidural analgesia, who were seen either in consultation prenatally or after requesting analgesia when in labour, consented to paravertebral blocks for the management of first stage of labour pain. Bilateral paravertebral blocks were performed at T10-L1 level, initially blocking all four levels with 4 ml bupivacaine 0.5% with epinephrine 1:200000 and then reducing the number of levels blocked to two and finally one. With the entry point 2 cm lateral to the inferior edge of the T11 spinous process, a 22G spinal needle was advanced perpendicular to all planes until contact was made with the transverse/superior articular process of T12, at a depth of 3-5 cm. The needle was then walked superiorly (T11) and inferiorly (T12 nerve root) off the transverse/articular process and advanced 1.5 cm into the paravertebral space. All four patients had relief of pain such that they were "comfortable" and able to cope with labour although they continued to experience deep pelvic and rectal pain. The patients tolerated the initiation of the blocks well, remained hemodynamically stable, and did not suffer any adverse effects.

CONCLUSION

Bilateral paravertebral block provides adequate analgesia for the first stage of labour and could be an alternative analgesic technique for some parturients with contraindications to conventional labour epidurals.

Regional anesthesia for obstetrics

The practice of administration of labor analgesia has undergone dramatic changes this decade. This is largely attributable to unparalleled interest in the field by many dedicated and capable investigators around the world. Through their efforts, this decade has witnessed the introduction of new techniques (pencil point needles, CSE, PCEA, ultradilute epidural regimens) that have permitted us to come closer than ever to realizing the goal of complete relief from the pain and suffering of labor while safeguarding the well-being of mother and child and minimizing effects on the labor process. Neuraxial anesthetic techniques and modern multimodal analgesic approaches to postoperative pain relief now minimize the effects of cesarean delivery on maternal satisfaction and participation in the birth process.