Effects of Epidural Anesthesia on Labor Progress

Uterine Contraction Parameters Before and During the Pre-Epidural Fluid Bolus: A Pilot Study

BACKGROUND

The first stage of labor is significantly longer with epidural analgesia use, implying an alteration in uterine contractility. Although the pre-epidural fluid bolus is used with every epidural and affects as many as 80% of laboring women, its effects on uterine contraction parameters are unknown.

DESIGN

Using a retrospective descriptive repeated measures design, we compared uterine contraction parameters including frequency, duration, peak intensity, resting tone, and Montevideo units at baseline and during the intravascular pre-epidural fluid bolus (Bolus) epochs for healthy laboring women at term gestation undergoing augmentation or induction.

METHOD

Contraction parameters were compared using data from fetal monitor strips with intrauterine pressure catheter instrumentation.

RESULTS

No significant differences were found between epochs for women receiving constant Pitocin dosages (n = 10) using Wilcoxon signed rank tests at .05 α level, but all parameters trended in the direction of improved contractility except frequency, which was unchanged.

CONCLUSIONS

These pilot study findings do not support the proposal that the pre-epidural fluid bolus is a contributor to decreased uterine contractility in any parameter. It is possible that the bolus improved myometrial perfusion and metabolic function in the contracting and resting states in less hydrated women.

The effects of intravenous dextrose 5%, Ringer's solution, and oral intake on the duration of labor stages in nulliparous women: a double-blind, randomized, controlled trial

Background and objectives: Childbirth consists of a three-stage period beginning with uterine contractions and ending in the expulsion of the placenta. The present study was conducted to compare the effects of Ringer's solution, dextrose solution 5%, and oral intake on the duration of total labor and labor stages (primary outcome) and the frequency of oxytocin administration and prolonged labor (secondary outcome) in nulliparous women with spontaneous vaginal delivery.Materials and methods: The present randomized clinical trial was conducted on 201 nulliparous women in labor assigned with a randomized block design to three groups, each receiving either Ringer's solution plus oral fluids, dextrose solution 5% solution plus oral fluids or oral fluids alone. The solutions were intravenously administered at a rate of 125 ml/h in the groups receiving the solutions and the subjects in the oral fluids group could consume liquids of their choice (water, orange juice, and apple juice). The duration of total labor and labor stages (the active stage, the second, and third stages of labor) were recorded by the researcher in minutes. Furthermore, the frequency of oxytocin administration and prolonged labor were recorded by the researcher by using a checklist. Data were analyzed using the Kruskal-Wallis test, Mann-Whitney's U-test, chi- square test and Fisher exact test.Results: The mean (±SD) duration of total labor was 301.2 (±50.0) minutes in the Ringer group, 171.9 (±36.4) in the dextrose 5% group, and 524.8 (±103.4) in the oral fluids group, suggesting a statistically significant intergroup difference (p < .001). The mean (±SD) duration of the active stage of labor was 276.7 (±91.3) minutes in the Ringer group, 150.6 (±78.5) in the dextrose 5% group, and 302.4 (±136.8) in the oral fluids group, suggesting a statistically significant intergroup difference (p < .001). A significant difference was also observed between the three groups in terms of the duration of the third stage of labor (p < .001); however, no significant differences were observed in terms of the duration of the second stage of labor (p = .058). Furthermore, a significant difference was observed between the three groups in terms of the need for oxytocin administration (p ≤ .001) and the frequency of prolonged labor (p = .001).Conclusion: The results suggest that the consumption of dextrose solution by nulliparous women reduces the duration of labor, the need for oxytocin administration and the frequency of prolonged labor compared to when Ringer's solution and oral fluids are used.

Risk Assessments of Epidural Analgesia During Labor and Delivery

Epidural analgesia (EA) is one of the methods of choice for labor pain relief, but its adverse effects on the mother and child remain controversial. The objective of this study was to determine whether there is an association between the use of EA and different aspects of labor. The author(s) analyzed the effect of EA on different aspects of labor in a retrospective cohort observational study of deliveries in a public Spanish hospital during a 3-year period. Women with EA administration were found to increase the risk of stimulated labor, reduce the percentage of spontaneous deliveries, increase the risk of instrumental labor due to stalled labor or loss of fetal well-being, and increase the percentage of episiotomies. However, women with EA were not and increased risk for perineal laceration or the condition of the membranes at the delivery or with the type of placental expulsion. Thus, the administration of EA should be assessed in each case by the health care professional.

The Effect of Epidural Analgesia Alone and in Association With Other Variables on the Risk of Cesarean Section

Introduction:

Epidural analgesia (EA) is the most widespread pharmacologic method of labor pain relief. There remains disagreement, however, regarding its adverse effects. The objective of this study was to determine the effect of EA administration on the risk of cesarean delivery and its causes (e.g., stalled labor, risk of loss of fetal well-being, among others) and the degree to which this effect may be modulated by mother-, newborn-, and labor-related variables.

Method:

A retrospective cohort observational study was conducted including all deliveries in a Spanish public hospital between March 2010 and March 2013 ( N = 2,450; EA = 562, non-EA = 1,888).

Results:

Risk of a cesarean section was significantly increased by EA administration (odds ratio [ OR] = 2.673; p < .0001). The percentage of cesarean deliveries due to the risk of loss of fetal well-being was significantly higher in the EA (47.8%) versus non-EA group (27.5%; OR = 1.739; p = 0.0012,). The EA-associated risk of cesarean section was not significantly modified as a function of maternal age or parity, fetal position, newborn weight, weeks of gestation, or sedation administration alone. However, these variables in combination may increase the risk. We present multivariate models for each group that account for these variables, allowing for estimation of the risk of a cesarean delivery if EA is administered.

Conclusion:

EA is associated with an increased risk of cesarean delivery. Other variables in combination (maternal age or parity, fetal position, newborn weight, weeks of gestation, or sedation administration) may increase this risk.

The degree of labor pain at the time of epidural analgesia in nulliparous women influences the obstetric outcome

Background

The increased pain at the latent phase can be associated with dysfunctional labor as well as increases in cesarean delivery frequency. We aimed to research the effect of the degree of pain at the time of epidural analgesia on the entire labor process including the mode of delivery.

Methods

We performed epidural analgesia to 102 nulliparous women on patients' request. We divided the group into three based on NRS (numeric rating scale) at the moment of epidural analgesia; mild pain, NRS 1-4; moderate pain, NRS 5-7; severe pain, NRS 8-10. The primary outcome was the mode of delivery (normal labor or cesarean delivery).

Results

There were significant differences in the mode of delivery among groups. Patients with severe labor pain had a significantly higher cesarean delivery compared to patients with moderate labor pain (P = 0.006). The duration of the first and second stage of labor, fetal heart rate, use of oxytocin and premature rupture of membranes had no differences in the three groups.

Conclusions

Our research showed that the degree of pain at the time of epidural analgesia request might influence the rate of cesarean delivery. Further research would be necessary for clarifying the mechanism that the augmentation of pain affects the mode of delivery.

Labor epidural analgesia and the incidence of instrumental assisted delivery

OBJECTIVE

To assess the influence of labor epidural analgesia on the course of labor and to determine its association with instrumental assisted delivery rate.

MATERIALS AND METHODS

A retrospective case-control study was performed during 2007-2011 aiming to identify the relation between epidural analgesia (EA) and instrumental assisted delivery (IAD) rate. All patients in whom instrumental assistance for delivery was applied were allocated into either case (parturients who received EA and had IAD) or control (parturients who did not receive EA but had IAD) groups. Maternal demographic data, pregnancy and delivery characteristics as well as neonatal short-term outcome were studied.

RESULTS

A total of 7675 vaginal deliveries occurred during the study period and 187 (2.43%) patients had IAD. Vacuum extraction was applied to 67 (2.16%) parturients who received EA, and to 120 (2.61%) who did not. The median duration of the first stage of labor was 510 min in the EA group as compared to 390 min in the control group (P=0.001). The median duration of the second stage of labor among cases and controls was 60 and 40 min, respectively (P<0.0005). Cases more often had their labor induced by oxytocin 80.3% as compared to 58.3% among controls (P=0.003). There was no significant association between the use of EA and increased IAD rate (OR=0.81; 95% CI, 0.60-1.09).

CONCLUSIONS

Labor EA did not increase the incidence of IAD and the risk of adverse neonatal outcomes, but was associated with prolonged first and second stages of labor.

Association between anxiety and pain in the latent phase of labour upon admission to the maternity hospital: a prospective, descriptive study

This study investigated the association between anxiety experienced by the mother, a request for analgesia, and the level of pain at maternity hospital admission in early labour. Anxiety levels were measured by the State-Trait Anxiety Inventory and pain was assessed using a Visual Analogue Scale. Anxiety and Visual Analogue Scale scores were compared using a linear regression model and indicated a statistically significant association between the anxiety state and degree of pain (p < 0.016; Y = 0.895 x score + 32.656). There was no significant association between anxiety and a request for epidural analgesia. During labour, an evaluation of anxiety should be associated with an assessment of the perceived degree of pain.

Identification of maternal characteristics associated with the use of epidural analgesia

The present survey aims to identify predictors associated with the use of epidural analgesia (EA). Therefore, from October 2007 to June 2008, a survey was conducted in 193 pregnant women (mean age 31.7 years (SD 4.9); 64.8% primipara) attending a German general hospital with a specialisation in integrative medicine. Questionnaires, including Antonovsky's sense of coherence (SOC) were delivered antepartum. Delivery data were recorded within the hospital quality management programme. The adjusted odds ratio (OR) for EA use was significantly greater than one for women who had previously used EA (adjusted OR =4.1; CI: 1.03-16.31) and for the desire for a delivery without pain (adjusted OR =3.05; CI: 1.36-6.83). The likelihood of EA use decreased in multipara (adjusted OR =0.05; CI: 0.01-0.22). SOC was not found to be an independent predictor for EA use. However, women with high SOC more often preferred a delivery without EA (p for trend =0.037). In conclusion, first time labour, the desire for a delivery without pain and previous use of EA are independent predictors for the use of EA in labour. Further studies should clarify the predictive role of SOC in pregnancy.

Comparison of Obstetric Pain, Anxiety, and Cervical Dilatation between Epidural Analgesia and No Analgesia group during Labor Stage I

PURPOSE

This research was done to compare obstetric pain, anxiety and cervical dilatation between an epidural analgesia group and a control group.

METHODS

Participants were assigned to the experimental or control group depending on their decisions for pain relief. Subjective / objective obstetric pain, anxiety level and cervical dilatation were measured and ANOVA was used for comparison of groups and paired t-test to make pre-post comparisons.

RESULTS

Homogeneity of pain, anxiety and cervical dilatation were assessed at the latent phase. Cervical dilatation was larger in the control group than the experimental group, at both the active and the transitional phase (F=22.9, p<.001; F=39.9, p<.001 respectively). The degree of pain and anxiety were not significantly different between the groups. Within the experimental group, subjective / objective pain and anxiety level were significantly lower postanalgesia compared to pre-analgesia in the active phase. All variables, except for sweating in the objective pain measurement, changed significantly at the transient phase.

CONCLUSION

The results of this evidence-based research indicate that epidural analgesia while effective in relieving pain and anxiety may have an adverse effect on the cervix during labor stage I. Epidural analgesia should be used carefully during cervical dilatation in labor stage I.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.