Comparative efficacy of epidural clonidine versus epidural fentanyl for treating breakthrough pain during labor: a randomized double-blind clinical trial

Efficacy and Safety of Epidural Chloroprocaine for Breakthrough Pain During Labor Analgesia: A Prospective, Double-Blind, Randomized Trial

INTRODUCTION

A significant number of women who undergo neuraxial labor analgesia experience breakthrough pain. Prompt mitigation of breakthrough pain is essential to improve maternal and fetal outcomes. We evaluated epidural chloroprocaine compared with ropivacaine in alleviating labor breakthrough pain.

METHODS

We performed a double-blind randomized controlled clinical trial between May and July 2023. Eligible parturients received epidural analgesia with ropivacaine and sufentanil. Those with breakthrough pain were randomized to receive either 0.125% epidural ropivacaine (group R) or chloroprocaine at concentrations of 0.5% (group C1), 1.0% (group C2), or 1.5% (group C3), all in a volume of 6 mL. The primary outcome was the treatment success rate, indicated by a decrease of at least 4 points on the numerical rating scale pain score 9 min after analgesic injection. Secondary outcomes and adverse effects were also recorded.

RESULTS

Out of 323 patients receiving epidural analgesia, 192 experienced breakthrough pain. After exclusion of three patients because of protocol deviation, there were 47, 48, 47, and 47 patients in group R, C1, C2, and C3, respectively. Group C3 demonstrated a higher treatment success rate (39/47, 83.0%) in managing breakthrough pain than group R (26/47, 55.3%), group C1 (12/48, 25.0%), and group C2 (30/47, 63.8%) (p < 0.001). Group C3 had lower numerical rating scale scores at 6 and 9 min after injection and required fewer patient-controlled epidural boluses than other groups. In addition, group C3 reported greater satisfaction than the other groups (p < 0.001). No significant differences were observed in obstetric or neonatal outcomes across these groups.

CONCLUSION

Parturients experiencing breakthrough pain could receive 1.5% epidural chloroprocaine, rather than lower chloroprocaine concentrations and ropivacaine, to achieve more rapid and better pain relief with higher patient satisfaction.

TRIAL REGISTRATION

Chinese Clinical Trial Registry, ChiCTR2300071069, http://www.chictr.org.cn/index.aspx .

ED90 of epidural esketamine with 0.075% ropivacaine for labor analgesia in nulliparous parturients: a prospective, randomized and dose-finding study

Background: Because it has been reported that racemic ketamine had a local anesthetic-sparing effect when used for epidural analgesia this would suggest the likelihood of a potential advantage (less pruritus) over opioid drugs. Esketamine has greater analgesic efficacy than racemic ketamine, but the optimum dosage regimen for epidural use is undetermined. The aim of this study was to determine the ED₉₀ of epidural esketamine when coadministered with 0.075% ropivacaine for labor analgesia. Methods: A total of 65 laboring nulliparous patients were enrolled in this study from 16 March 2022 to 15 October 2022. The patients were randomly assigned to receive 0, 0.25, 0.5, 0.75 or 1.0 mg/mL esketamine with 0.075% ropivacaine epidurally. An effective response to the epidural loading dose was defined as numerical rating scale pain score ≤3 at 30 min after the end of the epidural loading dose (10 mL of the ropivacaine 0.075% solution with the added esketamine). The ED₉₀ of epidural esketamine coadministered with 0.075% ropivacaine with 95% confidence intervals for labor analgesia was determined using probit regression. Secondary outcomes and side effects were recorded. Results: The estimated value of ED₉₀ with 95% CIs for epidural esketamine with 0.075% ropivacaine was 0.983 (0.704-2.468) mg/mL. The characteristics of sensory and motor block, consumption of ropivacaine per hour, duration of first or second stage, Apgar scores did not differ among the five groups. The incidence of mild dizziness in Group esketamine 1.0 mg/mL was significantly higher than that in other groups (p < 0.05). No statistical differences were found in other side effects among groups. Conclusion: The ED₉₀ value of epidural esketamine coadministered with 0.075% ropivacaine for labor analgesia in nulliparous parturients was about 1.0 mg/mL. Furthermore, our results suggested that epidural esketamine would cause dose-dependent mild dizziness especially at doses up to 1.0 mg/mL. As a single epidural additive, esketamine may not be suitable for labor analgesia. Future studies may investigate the appropriate dosage of esketamine at slightly higher concentrations of local anesthetics or larger initial volume of analgesia, or explore other potential advantages of esketamine. Clinical Trial Registration: (https://www.chictr.org.cn/bin/project/edit?pid=159764), identifier (ChiCTR2200057662).

Epidural analgesia in labor: A narrative review

Lumbar epidural is the most effective form of pain relief in labor with around 30% of laboring women in the UK and 60% in the USA receiving epidural analgesia. Associations of epidural on maternal, obstetric, and neonatal outcomes have been the subject of intense study, though a number of uncertainties persist. The present narrative review explores important areas of research surrounding epidural analgesia in obstetric patients including methods of initiation and administration, choice of local anesthetic solution, and the addition of adjuvants. Key meta-analyses exploring associations of epidural analgesia on maternal and neonatal outcomes are identified and summarized.

The ED50 and ED95 of Prophylactic Norepinephrine for Preventing Post-Spinal Hypotension During Cesarean Delivery Under Combined Spinal-Epidural Anesthesia: A Prospective Dose-Finding Study

Background: Hypotension commonly occurs with spinal anesthesia during cesarean delivery. Norepinephrine is an alternative to phenylephrine which can be used to prevent or treat hypotension, with better maintained cardiac output and less bradycardia. However, an appropriate initial prophylactic infusion dose of norepinephrine remains unclear. The aim of this study was to describe the dose-response relationship of prophylactic norepinephrine infusion during cesarean delivery under combined spinal-epidural anesthesia. Methods: We performed a prospective, randomized, double-blinded dose-finding study. One hundred patients undergoing elective cesarean delivery were randomly assigned to receive an infusion of norepinephrine at 0, 0.025, 0.05, 0.075 or 0.1 μg/kg/min initiated immediately after intrathecal injection of 10 mg bupivacaine combined with 5 µg sufentanil. An effective dose was considered when there was no hypotension (systolic blood pressure < 90 mm Hg or < 80% of baseline) during the time period from injection of intrathecal local anesthetic to delivery of the neonate. The primary aim was to determine the dose-response relationship of norepinephrine to prevent spinal anesthesia-induced hypotension. The median effective dose (ED₅₀) and 95% effective dose (ED₉₅) for norepinephrine were calculated utilizing probit analysis. Results: The proportion of patients with hypotension was 80, 70, 40, 15 and 5% at norepinephrine doses of 0, 0.025, 0.05, 0.075 and 0.1 μg/kg/min, respectively. The ED₅₀ and ED₉₅ were 0.042 (95% CI, 0.025-0.053) µg/kg/min and 0.097 (95% CI, 0.081-0.134) µg/kg/min, respectively. There were no differences in the Apgar scores (p = 0.685) or umbilical arterial pH (p = 0.485) measurements of the newborns among the treatment groups. Conclusion: A norepinephrine infusion of 0.1 μg/kg/min as an initial starting dose was effective for the prevention of spinal-induced hypotension.