Epidural Analgesia During Labor and Neonatal Hypoxic-Ischemic Encephalopathy.

Importance: Epidural analgesia is used by approximately 70% of birthing persons in the US to alleviate labor pain and is a common cause of elevated temperature in the birthing parent during labor, which, in turn, is associated with adverse neonatal outcomes such as hypoxic-ischemic encephalopathy (HIE). Objective: To determine whether epidural analgesia is associated with increased risk of HIE after adjusting for the birthing person's maximal temperature before epidural placement and for the propensity to get an epidural. Design, Setting, and Participants: This retrospective, population-based cohort study was conducted at 15 Kaiser Permanente Northern California hospitals. Participants included singleton neonates born at 35 weeks' or later gestational age between 2012 and 2019. Elective cesarean deliveries and deliveries within 2 hours of hospital admission were excluded. Data analysis was performed from November 2022 to June 2024. Exposure: The primary exposure was epidural analgesia during labor. Main Outcomes and Measures: The primary outcome was HIE, defined as the presence of both neonatal acidosis (ie, pH <7 or base deficit ≥10) and encephalopathy. The presence and timing of epidural analgesia and demographic, pregnancy, and labor characteristics were extracted from electronic medical records. A propensity score for receiving epidural analgesia was created including demographic variables and comorbidities predating epidural placement. Logistic regression was used to evaluate the association between epidural analgesia and HIE, adjusting for maximal birthing parent's temperature before epidural placement and the propensity for receiving an epidural. Results: Among 233 056 infants born at 35 weeks' or later gestational age by vaginal or unplanned cesarean delivery after at least 2 hours of in-hospital labor, 177 603 (76%) were exposed to epidural analgesia and 439 (0.19%) had HIE. On unadjusted analysis, epidural analgesia was associated with an increased risk of maximal temperature greater than 38 °C during labor (risk ratio [RR], 8.58; 95% CI, 8.06-9.14). Each degree increase in maximal temperature during labor was associated with nearly triple the odds of HIE (odds ratio [OR], 2.82; 95% CI, 2.51-3.17). However, there was no significant association between epidural analgesia and the risk of HIE either on crude (RR, 1.21; 95% CI, 0.96-1.53) or adjusted (adjusted OR, 0.93; 95% CI, 0.73-1.17) analyses. Conclusions and Relevance: In this cohort study including more than 230 000 parent-infant dyads, epidural analgesia was associated with increased maximal temperature during labor, a known risk factor for HIE. However, epidural analgesia was not associated with increased odds of HIE.

Effect of different concentrations of sufentanil combined with ropivacaine on epidural fever during labor: A single-center retrospective study.

Labor epidural analgesia (LEA) is associated with increased maternal body temperature; however, the responsible mechanism is unknown. Recent studies suggest that changes in EA affect the incidence of fever and that epidural sufentanil supplementation enhances analgesia and reduces the amount of local anesthetic. The aim of this study was to evaluate the effect of different concentrations of sufentanil combined with ropivacaine on intrapartum fever during delivery. We performed a retrospective study comparing maternal fever rates in patients receiving labor analgesia between December 2018 and January 2019. Each patient receiving different concentrations of sufentanil in their EA received either proposal H (0.08% ropivacaine + 0.4 µg/mL sufentanil) or proposal L (0.08% ropivacaine + 0.2 µg/mL sufentanil), with the same nulliparous status. The primary outcome of this study was the incidence of intrapartum maternal fever, which was defined as any temperature ≥ 38°C during labor using Fisher exact test. Secondary outcome measures included visual analog scale (VAS) pain scores, birth events, and neonatal outcomes. We observed a perinatal fever incidence rate of 11.7% in the group receiving proposal L, while the incidence rate was 19.8% in the group receiving proposal H (P = .001). Five hours after administration, the average body temperature of the puerpera decreased significantly in the proposal L group compared with proposal H group. In addition, treatment with 0.2 µg/mL sufentanil provided satisfactory pain relief during labor, shortened the first stage of labor and total labor time, reduced oxytocin use, and had no significant adverse effects on neonatal outcomes. EA may increase the risk of intrapartum epidural-associated fever. Compared with the 0.4 µg/mL sufentanil group, the 0.2 µg/mL sufentanil group can provide better analgesia and improve maternal fever. These retrospective results highlighted the importance of prospective and mechanistic studies of maternal fever associated with intraspinal analgesia.

Pocket warming of bupivacaine with fentanyl to shorten onset of labor epidural analgesia: A double-blind randomized controlled clinical trial.

Shortening analgesic onset has been researched and it has been documented that prewarming epidural medications to body temperature (37°C) prior to administration increases medication efficacy. Our double-blind randomized controlled trial was designed to investigate if a lower degree of prewarming in providers' pockets could achieve similar results without the need of a bedside incubator. A total of 136 parturients were randomized into either the pocket-warmed group or the room temperature group to receive 10 mL of 0.125% bupivacaine with 2 µg/mL fentanyl epidural bolus at either the 27.8 ±1.7°C or 22.1 ±1.0°C temperatures, respectively. Primary outcome, time to analgesic onset (verbal rating scale pain score ≤ 3) was recorded in 0-, 5-, 10-, 15-, 20-, 30-, and 60-minutes intervals. It was observed that the pocket-warming group (n = 64) and room temperature group (n = 72) had no significant difference of analgesic onset time (median 8 vs. 6.2 minutes; p = 0.322). The incidence of adverse events such as hypotension, fever (≥ 38°C), nausea, vomiting, and number of top-off epidural boluses, as well as patient satisfaction rates and mode of delivery, were not significantly different between the groups as well. Further research is warranted to confirm these findings and explore the impact of different temperatures on analgesic onset time as well as the logistical issues associated with their clinical implementations.

Impact of nitrous oxide use on parturient recall of neuraxial analgesia risks.

STUDY OBJECTIVE: Nitrous oxide affects memory and recall. We aimed to determine if using nitrous oxide during labor affected patients' ability to learn and recall the risks and benefits of neuraxial analgesia. DESIGN: Single-center, prospective cohort study. SETTING: Labor and delivery unit in a large academic medical center. PATIENTS: Nulliparous patients with spontaneous or planned induction of labor. INTERVENTIONS: Parturients chose whether to use nitrous oxide during labor. At the discussion for epidural consent, 4 risks were described: headache, infection, nerve damage, bleeding. MEASUREMENTS: Labor pain score, time from nitrous oxide discontinuation, and cervical dilation were documented at the discussion of epidural risks. Patients were assessed for unprompted recall and prompted recall of epidural risks on postpartum day 1 and unprompted recall at postpartum week 6. The number and proportion of patients who indicated each true risk (unprompted and prompted recall) or distractor (prompted recall only) were summarized by treatment group and results compared using Pearson χ2 tests. MAIN RESULTS: Of the 403 enrolled patients, 294 (73%) did not use nitrous oxide, and 109 (27%) did. The 2 groups were similar except women who used nitrous oxide were more likely to be cared for by midwives and had higher pain scores at their epidural request. Scores for unprompted or prompted recall of epidural risks were not different between women who received or did not receive nitrous oxide. All 4 risks were recalled unprompted by only 3% in the nitrous oxide group and by 6% in the group not receiving nitrous oxide (P = .18). CONCLUSIONS: The use of nitrous oxide for labor analgesia does not adversely influence a parturient's ability to recall the risks of epidural placement. Patients who receive nitrous oxide for labor analgesia should be considered eligible to provide consent for subsequent procedures.

Association between neutrophil-to-lymphocyte ratio and epidural-related maternal fever in Chinese parturients: a prospective cohort study.

OBJECTIVE: Epidural analgesia could increase the risk of maternal fever during labor, and the potential mechanisms involved inflammation. Neutrophil-to-lymphocyte ratio (NLR) was a sensitive inflammatory composite indicator and related to adverse outcomes in parturients. This study aimed to investigate the association between NLR levels and epidural related maternal fever (ERMF). METHODS: This prospective cohort study included 614 parturients who underwent epidural analgesia at the Women's Hospital School of Medicine Zhejiang University from November 2021 to May 2023. NLR level was calculated before epidural analgesia for women. The outcome was ERMF. Univariate and multivariate logistic regression models were utilized to explore the association between NLR level and ERMF. And the association was further investigated in subgroups of age, body mass index (BMI) before pregnancy, and parity of delivery. The results were presented as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Totally, 614 parturients, of whom 171 (27.85%) had ERMF. High NLR level was associated with higher incidence of ERMF (OR = 2.70, 95% CI: 1.58-4.69). Parturients with ERMF had higher proportion of postpartum hemorrhage, longer labor times, and other adverse outcomes in parturients. The association also observed in subgroups of age <35 years old (OR = 2.74, 95% CI: 1.55-4.29), BMI <24 kg/m2 before pregnancy (OR = 2.32, 95% CI: 1.32-4.13), BMI ≥24 kg/m2 before pregnancy (OR = 38.28, 95%CI: 3.67-854.66), primipara (OR = 2.26, 95% CI:1.27-4.04), and multipara (OR = 30.60, 95% CI: 3.73-734.03). CONCLUSION: High NLR levels were associated with ERMF in women. It indicated that physicians may measure NLR levels as a regular measurement, which may beneficial for pregnancy outcomes.

Epidural analgesia in labour: separating fact from fiction for autism and neurodevelopment.

Having epidural analgesia in labour has been associated with a later diagnosis of autism spectrum disorder in the offspring, resulting in concerns about childhood wellbeing. Neurodevelopmental changes are inconsistently reported in the literature, creating challenges in the interpretation of these findings. Here we explore the limitations of the current evidence base, and why findings differ between studies, concluding that the current body of evidence does not support a causal association between use of epidural analgesia in labour and autism spectrum disorder.

Effect of dural puncture epidural block technique on fetal heart rate variability during labor analgesia.

PURPOSE: To explore the effect of dural puncture epidural (DPE) block technique on fetal heart rate variability (HRV) during labor analgesia. METHODS: Sixty full-term primiparas who were in our hospital from April 2021 to October 2021 were selected and randomized into epidural analgesia (CEA) and dural puncture epidural analgesia (DPEA) groups (n = 30). After a successful epidural puncture, routine epidural catheter (EC) was performed in CEA group, and spinal anesthesia needle (as an EC) was used to puncture the dura mater to subarachnoid space in DPE group. Anesthetics were injected through EC. The time when the temperature sensation plane reached T10 (W1) and visual analog pain score (VAS), baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 were recorded. Apgar scores at 1 min, 5 min, and 10 min of neonates after delivery were recorded. RESULTS: The onset time of anesthesia in CEA group was significantly longer than that in DPEA group (p < .05). However, there are no significant differences in W1, VAS, baseline heart rate score, amplitude variation score, cycle variation score, acceleration score, deceleration score, and total score of the first contraction after W1 between the two groups (p > .05). Moreover, the Apgar scores at 1 min, 5 min and 10 min of neonates after delivery were not notably different between the two groups (p > .05). CONCLUSION: Compared with CEA, DPE block technique in labor analgesia relieves maternal pain without adverse effects on fetal HRV and newborns.

The application of DPE, CSEA, and EA in labor analgesia for nulliparous women and their impact on maternal and infant safety.

This work compared the effects of dural puncture epidural (DPE), combined spinal epidural analgesia (CSEA) and epidural analgesia (EA) on labor analgesia for primiparae and their impacts on maternal and infant safety. A total of 204 primiparae in need of labor analgesia for vaginal delivery were allocated to DPE, CSEA and EA groups. At 10 min, 30 min and 1 h after analgesia, the DPE and CSEA groups showed lower VAS scores and quicker onset of action than EA group. There was no significant difference in the duration of analgesia and labor and fetal decelerations among the 3 groups. At 1 min and 5 min after childbirth, the neonatal Apgar scores showed no significant difference between the 3 groups. The Bromage scores of DPE and EA groups were lower than those of CSEA group. The incidence of pruritus, hypotension, and postpartum headache in DPE and EA groups were lower than those in CSEA group. To sum up, the efficacy of DPE in labor analgesia for primiparae is similar to that of CSEA, with no obvious effect on labor stage and neonatal Apgar score, no additional complications and less LLMB, pruritus, hypotension and postpartum headache.

Behavioural and neuropsychological outcomes in children exposed in utero to maternal labour epidural analgesia.

BACKGROUND: Recent studies report conflicting results regarding the relationship between labour epidural analgesia (LEA) in mothers and neurodevelopmental disorders in their offspring. We evaluated behavioural and neuropsychological test scores in children of mothers who used LEA. METHODS: Children enrolled in the Raine Study from Western Australia and delivered vaginally from a singleton pregnancy between 1989 and 1992 were evaluated. Children exposed to LEA were compared with unexposed children. The primary outcome was the parent-reported Child Behaviour Checklist (CBCL) reporting total, internalising, and externalising behavioural problem scores at age 10 yr. Score differences, an increased risk of clinical deficit, and a dose-response based on the duration of LEA exposure were assessed. Secondary outcomes included language, motor function, cognition, and autistic traits. RESULTS: Of 2180 children, 850 (39.0%) were exposed to LEA. After adjustment for covariates, exposed children had minimally increased CBCL total scores (+1.41 points; 95% confidence interval [CI] 0.09 to 2.73; P=0.037), but not internalising (+1.13 points; 95% CI -0.08 to 2.34; P=0.066) or externalising (+1.08 points; 95% CI -0.08 to 2.24; P=0.068) subscale subscores. Increased risk of clinical deficit was not observed for any CBCL score. For secondary outcomes, score differences were inconsistently observed in motor function and cognition. Increased exposure duration was not associated with worse scores in any outcomes. CONCLUSIONS: Although LEA exposure was associated with slightly higher total behavioural scores, there was no difference in subscores, increased risk of clinical deficits, or dose-response relationship. These results argue against LEA exposure being associated with consistent, clinically significant neurodevelopmental deficits in children.

Effects of epidural analgesia on intrapartum maternal fever and maternal outcomes: an updated systematic review and meta-analysis.

OBJECTIVE: Epidural-related maternal fever in women is a common clinical phenomenon that leads to adverse consequences for mothers and neonates. The meta-analysis aimed to quantify the risk for intrapartum maternal fever after epidural analgesia (EA) stratified according to parity. The secondary objective was to investigate the association between EA and maternal outcomes. METHODS: An electronic literature search of the Medline/PubMed, Embase, Cochrane Library, Wanfang Data, and China National Knowledge Infrastructure databases was performed to identify studies reporting the occurrence of intrapartum fever in parturients. Studies were reviewed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and meta-analysis was performed using Review Manager version 5.3. RESULTS: Seventeen randomized controlled trials (RCTs) (5959 parturients) were included. Odds ratios for maternal fever in the analysis were 4.17 (95% confidence interval (CI) 2.93-5.94) and 5.83 (95% CI 4.96-6.87), respectively. Results of subgroup analysis according to parity were consistent. EA significantly prolonged the length of the first stage of labor (MD 34.52 [95% CI 12.13-56.91]) and the second stage of labor (MD 9.10 [95% CI 4.51-13.68]). Parturients who received EA were more likely to undergo instrumental delivery (OR 2.03 [95% CI 1.44-2.86]) and oxytocin augmentation (OR 1.45 [95% CI 1.12-1.88]). There were no differences in cesarean delivery rates between the EA and non-EA groups. CONCLUSIONS: Parturients who received EA exhibited a higher incidence of intrapartum fever. Credibility of the subgroup analyses was low because the mixed group did not effectively represent multiparas.

Using part of the initial analgesic dose as the epidural test dose did not delay the onset of labor analgesia: a randomized controlled clinical trial.

BACKGROUND: Epidural test dose for labor analgesia is controversial and varies widely in clinical practice. It is currently unclear whether using a portion of the initial dose for analgesia as the test dose delays the onset time of analgesia, compared to the traditional test dose. METHODS: One hundred and twenty-six parturients who chose epidural analgesia during labor were randomly assigned to two groups. The first dose in group L was 3 ml 1.5% lidocaine, and in the RF group was 10 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. After 3 min of observation, both groups received 8 ml 0.1% ropivacaine combined with 2 µg/ml fentanyl. The onset time of analgesia, motor and sensory blockade level, numerical pain rating scale, patient satisfaction score, and side effects were recorded. RESULTS: The onset time of analgesia in group RF was similar to that in group L (group RF vs group L, 7.0 [5.0-9.0] minutes vs 8.0 [5.0-11.0] minutes, p = 0.197). The incidence of foot numbness (group RF vs group L, 34.9% vs 57.1%, p = 0.020) and foot warming (group RF vs group L, 15.9% vs 47.6%, p < 0.001) in group RF was significantly lower than that in group L. There was no difference between the two groups on other outcomes. CONCLUSIONS: Compared with 1.5% lidocaine 3 ml, 0.1% ropivacaine 10 ml combined with 2 µg/ml fentanyl as an epidural test dose did not delay the onset of labor analgesia, and the side effects were slightly reduced. CLINICAL TRIAL REGISTRATION: http://www.chictr.org.cn (ChiCTR2100043071).

Severe back labor pain masks a scald caused by shower hydrotherapy: a case report.

Shower hydrotherapy is generally considered benign during labor. We report a case of extensive scalds in a primigravida who used shower hydrotherapy to treat severe back labor pain from fetal malposition. Interestingly, her back pain was so severe that she felt no pain as her scald developed, describing the hot water from the showerhead as the only measure which "soothed" her pain. Her scald was diagnosed presumptively during assessment for epidural analgesia. The nature of her back labor pain, associated with occiput posterior fetal head position and her management are described. Severe pain from persistent fetal malposition may alter somatic pain perception during labor, increasing burn risks during shower hydrotherapy. These women are also at increased risk of operative delivery and infection risks from inadvertent neuraxial blockade after burns. Improved prevention strategies and vigilance for scalds are warranted in women with severe back labor undergoing shower hydrotherapy, including by anesthesiologists assessing them for neuraxial blockade.

Association Between Intrapartum Nitrous Oxide for Labor Analgesia and Short-Term Neonatal Outcomes.

OBJECTIVE: To evaluate the association between intrapartum nitrous oxide use and adverse short-term neonatal outcomes. METHODS: This was a retrospective cohort study of individuals with singleton gestations at 35 or more weeks who attempted labor and delivered at an academic hospital between June 1, 2015, and February 28, 2020. Data were extracted from the electronic medical record using billing and diagnostic codes. Patients were classified based on whether they received no intrapartum analgesia or received nitrous oxide only. Those who received other analgesia types were excluded. The primary outcome was neonatal intensive care unit (NICU) admission. Secondary outcomes included Apgar score less than 7 at 1 minute and 5 minutes, respiratory composite outcome (including meconium aspiration syndrome, neonatal bronchopulmonary disorders, neonatal transient tachypnea, and other neonatal respiratory distress that required NICU admission), hypoglycemia, and hyperbilirubinemia. Univariable and multivariable analyses were used to estimate the association between nitrous oxide exposure intrapartum and the selected outcomes. RESULTS: Of 6,047 included, 4,153 (68.7%) received no analgesia, and 1,894 (31.3%) received nitrous oxide only. In comparison with individuals who received no analgesia, those who received nitrous oxide were more likely to be nulliparous, be of Black racial identity, have noncommercial insurance, and be less likely to deliver by intrapartum cesarean. The reception of nitrous oxide, compared with the reception of no analgesia, was associated with a lower likelihood of NICU admission (6.4% vs 8.1%; adjusted odds ratio [aOR] 0.77, 95% CI, 0.62-0.96) and an increased likelihood of neonatal hyperbilirubinemia (aOR 1.23, 95% CI, 1.08-1.41). Inhaled nitrous oxide exposure, in comparison with the reception of no analgesia, was not associated with the other secondary outcomes, including Apgar score less than 7 at 1 minute (odds ratio [OR] 0.74, 95% CI, 0.50-1.10) or 5 minutes (OR 0.91, 95% CI, 0.32-2.60), respiratory composite outcome (OR 0.91, 95% CI, 0.70-1.17), and hypoglycemia (OR 0.82, 95% CI, 0.64-1.05). CONCLUSION: In this single-center retrospective cohort of low-risk patients, intrapartum inhaled nitrous oxide, compared with the reception of no analgesia, was associated with a decreased risk for NICU admission but with an increased risk for hyperbilirubinemia; other outcomes did not differ. These findings may be used to counsel patients when considering nitrous oxide for labor analgesia.

Efficacy and safety of nalbuphine for epidural labor analgesia at high altitude: An observational study.

Xining is located at the eastern edge of the Qinghai-Tibet Plateau, with an average altitude of >7000 feet (>2000 m). Nalbuphine is a kappa-opioid receptor agonist that can provide analgesia with fewer side effects than other opioid analgesics. This study aimed to evaluate pain control, side effects, and neonatal outcomes from combining nalbuphine with sufentanil and ropivacaine in 600 women during epidural anesthesia while giving birth at a high altitude in Xining, China. A total of 600 parturients receiving epidural labor analgesia were randomly divided into 2 groups, each group 300 parturients. The nalbuphine group received nalbuphine, sufentanil, and ropivacain, the control group only received sufentanil and ropivacain. The analgesic effect was evaluated through the Visual Analogue Scale scores. Neonatal outcomes were mainly evaluated through the Apgar Scores. Compared to the control group, the nalbuphine group showed lower Visual Analogue Scale scores at all time points after analgesia (P < .05). In comparison with the control group, parturients in the nalbuphine group showed lower incidence rates of fever at delivery, 24-hour postpartum bleeding, and pruritus (P < .05). However, between the 2 groups, there were no statistically significant differences in the remaining maternal and infant outcomes and neonatal outcomes (P > .05). Moreover, no adverse effects on neonatal outcomes were observed. The findings from this study support findings from previous studies that nalbuphine provided safe epidural analgesia without significant side effects for the mother and infant, and showed both safety and efficacy when used during labor at high altitude.