Does epidural analgesia cause dystocia?

"Active labor" duration and dilation rates among low-risk, nulliparous women with spontaneous labor onset: a systematic review

INTRODUCTION

Laboring women are often admitted to labor units under criteria that are commonly associated with the onset of active-phase labor (i.e., cervical dilatation of 3-5 cm in the presence of regular contractions). Beginning with these criteria through complete dilatation, this systematic review describes labor duration and cervical dilation rates among low-risk, nulliparous women with spontaneous labor onset.

METHODS

Studies published in English (between 1990 and 2008) were identified via MEDLINE and CINAHL searches. Data were abstracted and weighted "active labor" durations (i.e., from 3-5 cm through complete dilatation) and linear dilation rates were calculated.

RESULTS

Eighteen studies (n = 7009) reported mean "active labor" duration. The weighted mean duration was 6.0 hours, and the calculated dilation rate was 1.2 cm per hour. These findings closely parallel those found at the median. At the statistical limits, the weighted "active labor" duration was 13.4 hours (mean + 2 standard deviations) and the dilation rate was 0.6 cm per hour (mean - 2 standard deviations).

DISCUSSION

These findings indicate that nulliparous women with spontaneous labor onset have longer "active" labors and therefore slower dilation rates than are traditionally associated with active labor when commonly used criteria are applied as the starting point. Revision of existing active labor expectations and/or criteria used to prospectively identify active phase onset is warranted.

Some Swedish women's experiences of prolonged labour

OBJECTIVE

to elucidate women's experiences of prolonged labour.

DESIGN

qualitative research interviews were conducted and thematic content analysis was applied.

PARTICIPANTS

10 primiparae who, 1-3 months previously, had a prolonged labour with assisted vaginal or caesarean delivery.

FINDINGS

the narratives about giving birth were interpreted and formulated into three themes and six sub-themes. The first theme, 'being caught up in labour', described the sense of not making progress during labour. The second theme was 'being out of control', and was related to the women's insufficient control of their own bodily processes, and consisted of descriptions of exhaustion and powerlessness. The third theme was 'being dependent on others', and described the women's dependence on care and on the support of the caregivers, and included descriptions of caregivers' assistance with birth as an experience of being relieved from pain and distress.

KEY CONCLUSIONS

the experience of giving birth was not the experience of a healthy woman in labour, but one of severe labour pains that seemed to go on forever. The experience of prolonged labour could be understood as an experience of suddenly falling ill or finding oneself in a life-threatening condition associated with intractable pain, dependence on others and an overwhelming fear of losing oneself.

IMPLICATIONS FOR PRACTICE

women with prolonged labour are more dependent on their caregivers than are women without prolonged labour. They have a special need for extra support and encouragement during the delivery as well as increased nursing and midwifery care.

Induction of labor with oxytocin increases cesarean section rate as compared with oxytocin for augmentation of spontaneous labor in nulliparous parturients controlled for lumbar epidural analgesia

STUDY OBJECTIVES

To study labor outcomes in parturients receiving oxytocin for augmentation or induction of labor, in the presence of labor epidural analgesia.

DESIGN

Retrospective study of data from a continuous quality improvement database.

SETTING

Tertiary-care hospital with more than 8000 deliveries per annum.

MEASUREMENTS AND MAIN RESULTS

Of the 1671 healthy nulliparous women with singleton pregnancies and who requested labor epidural analgesia at our institution, 675 patients received oxytocin during elective induction of labor, whereas 996 patients received oxytocin for augmentation of spontaneous labor. Measured variables were cervical dilatation at time of epidural analgesia request, epidural insertion to 10-cm time, duration of stage 2 of labor, normal spontaneous vaginal delivery rate, cesarean section rate, operative vaginal delivery rate, and baby weight. Women admitted for induction of labor requested epidural analgesia sooner than those who had their labor augmented (p < 0.001). The incidence of cesarean section was higher in the induced group (p = 0.008).

CONCLUSION

Patients who have their labor induced request analgesia sooner and are at a higher risk of cesarean section than are patients who go into labor spontaneously. Any study that purports to assess the effects of epidural analgesia in labor should distinguish between induced and augmented/spontaneous labor.

Epidural analgesia for pain relief in labour and childbirth - a review with a systematic approach

BACKGROUND

Clinical ambiguity concerning effects of epidural analgesia for pain relief in labour seems to reflect a need for evidence-based knowledge for midwives.

AIMS

This study aimed to review, with a systematic approach, the literature about effects and risks associated with the use of epidural analgesia for pain relief in labour and childbirth.

DESIGN

A structured question was formulated and used for deriving search terms, establishing the inclusion of certain criteria and retrieving articles, i.e. what are the effects of epidural analgesia for pain relief in labour and childbirth? References were obtained through searches using MeSH-terms in Medline and Subheadings (SH) in CINAHL (e.g. Obstetrical Analgesia combined either with psychology or adverse effects and together with, Dystocia, Caesarean Section, Infant Newborn and Breastfeeding). The articles were divided into prospective randomized trials (C), non-randomized prospective studies (P) and retrospective studies (R). Scientific quality of the studies was assessed on a three-grade scale: high scientific quality (I), moderate scientific quality (II) or low scientific quality (III).

RESULTS

Twenty-four articles were retrieved and systematically assessed. Seven studies were judged as high quality, 15 as moderate quality and two as low quality. The majority of studies appraised in this review failed to obtain or establish a cause and effect relationship. According to the data, it seems clear that the use of epidural analgesia is considered to be an effective method of pain relief during labour and childbirth from the perspective of women giving birth.

RELEVANCE TO CLINICAL PRACTICE

Midwives and doctors can recommend this form of pain relief. However, information about possible associations with adverse effects in mothers and infants must be provided to expectant couples.

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.

Ropivacaine 1 mg/ml, plus fentanyl 2 microg/ml for epidural analgesia during labour. Is mode of administration important?

BACKGROUND

Patient-controlled epidural analgesia (PCEA) with a moderate to high concentration of bupivacaine in obstetrics has been shown to give comparable analgesia and even higher level of satisfaction compared to continuous epidural infusion. We hypothesised that the use of a very low concentration technique (ropivacaine/fentanyl) might result in excessive dosing in the PCEA group, more motor blockade and a negative impact on spontaneous delivery rate.

METHODS

We conducted a randomised, double-blind study of 60 nulliparous women at term comparing low concentration ropivacaine/fentanyl administered in either patient-controlled or fixed continuous infusion mode. Parturients with known predictors of painful deliveries, i.e. breech presentation, primary induction of labour, were not included. Deliveries within 90 min from the start of epidural analgesia were omitted from the evaluation.

RESULTS

We found that both groups required a mean of 12 ml/h low concentration mixture (loading and midwife rescue boluses included). There was no difference between groups with respect to spontaneous delivery rate (71%). This low concentration technique resulted in haemodynamic stability without crystalloid preloading, infusion or vasopressor use. Motor blockade of clinical importance was not detected in any patient.

CONCLUSION

We conclude that epidural use of ropivacaine 1 mg/ml+fentanyl 2 microg/ml provides effective analgesia with equal volume requirements irrespective of administration mode, with a high spontaneous delivery rate. Choice of PCEA or CEI (continuous epidural infusion) should be directed by other considerations, most importantly compliance of midwife and possible reduction in workload for anaesthesiology staff.

Labor epidurals improve outcomes for babies of mothers at high risk for unscheduled cesarean section

CONTEXT

Epidural placement for labor in the general population of laboring women is associated with increased incidence of operative deliveries, prolongation of labor, and may be associated with an increased cesarean section rate. The risks and benefits associated with epidural placement for labor in the subpopulation of mothers at high risk for cesarean section have not been studied.

OBJECTIVE

To determine if a population of mothers and babies at high risk for cesarean section will have improved outcomes with labor epidural placement.

DESIGN

A decision and cost analysis examining epidural placement for labor on a population of women who are at high risk for unscheduled cesarean section and may benefit from scheduled cesarean section as determined by threshold analysis was performed. Outcomes and probabilities were determined through analysis of the Department of Defense's 1996 National Quality Management Program (NQMP) Birth Product Line data set containing more than 7000 deliveries. Outcomes were defined using variables comprised of all documented conditions that occurred during the peripartum and neonatal hospitalizations. The 1997 NQMP data set was used to validate the results.

SETTING

Military Treatment Facilities throughout the United States and abroad and civilian facilities in the United States providing care to military dependents.

PATIENT POPULATION

Active duty and dependent pregnant women and babies.

RESULTS

About 8% of mothers in this patient population were found to be at high risk for cesarean section. The decision and cost analyses showed that babies of the high risk mothers who received epidurals for labor had better clinical outcomes (p<0.05) and the procedure was cost neutral (p=0.23). The procedure did not increase the frequency of cesarean section, and there was no effect on maternal outcomes scores. These results were confirmed by the validation study.

CONCLUSIONS

There is a sizable subpopulation of women at high risk for cesarean section whose babies may have better outcomes with epidural placement with no sacrifice in maternal outcomes or costs.

Obstetric analgesia

Several analgesic options are available for patients during labor. Selection of the appropriate technique must be individualized. Education and preparation begins during prenatal care. If medications are to be used, the risks and benefits to the mother and infant must be considered. Continued patient-doctor communication throughout labor is essential. Patient preferences, tempered by sound medical judgement, should guide the selection of the optimal modality for pain control during labor.

Predictors of recommendation and acceptance of intrapartum epidural analgesia

We conducted this prospective study to characterize the obstetric and sociodemographic variables that predict physicians' recommendations and patients' acceptance of intrapartum epidural analgesia. The study population consisted of 447 consecutive, low-risk parturients in early active labor. Epidural analgesia was recommended to 393 patients (87.9%), however only 164 (41.7%) consented to receive it. A multiple logistic regression analysis demonstrated that the severity of pain, as assessed by the medical staff (odds ratio [OR] = 1.5, 95% confidence interval [CI] 1.13, 1.93), low parity (OR = 0.57, 95% CI 0.44, 0.74), and low maternal age (OR = 0.89, 95% CI 0.79, 0.99) were significant factors affecting recommendations of epidural analgesia. In a multivariate analysis, severity of subjective pain (OR = 1.39, 95% CI 1.16, 1.68), low parity (OR = 0.80, 95% CI 0.73, 0.99), high education (OR = 90.09, 95% CI 27.02,257.06), and the patients' being secular compared with religious (OR = 2.14, 95% CI 1.08,4.21) were found to be independent predictors of acceptance of epidural analgesia. There are differences between patients offered and those not offered epidural analgesia and between parturients who accept and those who do not accept this analgesia.

IMPLICATIONS

We studied the factors that influence the recommendation of epidural analgesia by obstetricians, as well as its acceptance by the laboring patients at a university hospital in Israel. Epidural analgesia was recommended more often to low parity, younger women exhibiting more pain. Parturients who perceived greater pain were more secular, had low parity, and had a higher level of education were more likely to accept it.

Epidural anesthesia and the progress of labor

Epidural block remains the most effective, safe approach to pain relief for labor, and demand for its use continues to grow. Opposition to epidural block in labor, based on a widely acclaimed 1993 study, has led to the widespread discouragement of its use for laboring women and the denial of payment to some anesthesiologists who use it. Within the past year, strong evidence has emerged showing that the association of epidural block with dystocia and cesarean section is casual and not causal.