The Impact of Local Anesthetic Solution Temperature on Epidural-related Maternal Fever

This study investigates how the temperature of local anesthetics affects maternal fever related to epidural analgesia during childbirth. The research is a prospective, randomized controlled trial involving 424 participants from two hospitals. The primary objective is to investigate the impact of local anesthetic solution temperature on intrapartum fever in parturients. Secondary goals include assessing the impact on the efficacy of epidural analgesia and various maternal and neonatal outcomes. Participants will receive either 37°C or 23°C anesthetic solutions, and data will be collected on fever rates, pain scores, and other health indicators. The study runs from January 2024 to December 2026.

Study Overview

• Status: Recruiting
• Conditions: Fever; Analgesia, Epidural; Intrapartum Fever; Epidural Related Maternal Fever
• Intervention / Treatment: Procedure: In the context of epidural analgesia, the temperature of the local anesthetic solution is elevated to 37°C utilizing a blood transfusion and infusion warmer.

Detailed Description

Background:

Maternal fever during labor is common, with an incidence of about 33%, often due to infection, epidural analgesia, or environmental factors. Multiple studies have indicated that the rate of intrapartum fever in women who receive epidural analgesia is approximately between 15% and 25%. After epidural analgesia, the risk of maternal fever significantly increases, a condition known as Epidural-Related Maternal Fever (ERMF). ERMF not only increases unnecessary antibiotic use but may also lead to unplanned cesarean sections, increased perinatal bleeding, and other complications. Moreover, any cause of intrapartum fever, including ERMF, can increase the incidence of neonatal brain injury by approximately 2.79 times. With the popularization of the concept of painless childbirth, ERMF has increasingly attracted people's attention. Despite being identified in 1989, the pathogenesis of ERMF remains unclear, with several mechanisms proposed, including infection, sympathetic blockade, and non-infectious inflammation induced by local anesthetics.

Methods:

This is a prospective randomized controlled study with 424 participants receiving epidural analgesia at two hospitals from October 2024 to October 2027. Participants will be randomly assigned to receive either 37°C or 23°C local anesthetic solutions. The study will measure maternal fever rates, the time for pain scores to decrease, and peripheral perfusion index at various intervals. Maternal and neonatal outcomes, including antibiotic usage, sepsis incidence, and Apgar scores, will be recorded.

Possible Conclusions:

The study aims to determine if the temperature of local anesthetics influences the incidence of ERMF. It also seeks to assess the impact of anesthetic temperature on the onset and duration of epidural analgesia and various maternal and neonatal health outcomes. The findings may provide evidence on whether warming local anesthetics can reduce the risk of ERMF and improve maternal and neonatal health during labor.

• Study Type: Interventional
• Enrollment (Estimated): 424
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Dapeng Chen; Phone Number: +8618550044050; Email: hisoka52@outlook.com

Study Locations

• China
  • Jiangsu
    • Suzhou, Jiangsu, China
      • Not yet recruiting
      • Suzhou Municipal Hospital
      • Contact: Lei Wei; Phone Number: +8613814874405; Email: 64624369@qq.com
    • Suzhou, Jiangsu, China, 215000
      • Recruiting
      • Ethical Committee of the First Affiliated Hospital of Soochow University
      • Contact: Zhou-lin Lu; Phone Number: 008613914086271

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Requesting epidural analgesia;
2. Aged 18 or older;
3. At least 37 weeks of gestation;
4. Those delivering vaginally.

Exclusion Criteria:

1. Contraindications to epidural analgesia;
2. Pre-existing fever (≥38°C) before labor;
3. Use of NSAIDs or other types of antipyretics before labor;
4. Multiple pregnancy (carrying more than one fetus);
5. Fetal demise (stillbirth);
6. Severe preeclampsia;
7. Women who refuse to participate.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Observation group; Participants will be assigned to receive 37°C local anesthetic solutions.	Procedure: In the context of epidural analgesia, the temperature of the local anesthetic solution is elevated to 37°C utilizing a blood transfusion and infusion warmer.; For the observation group, after reactivating the analgesic pump's exhaust procedure to clear the air from the tubing, the output tubing of the analgesic pump is first connected to the epidural catheter. Following this, a blood transfusion and infusion warmer (manufactured by Barkey GmbH & Co. KG., Germany, model S-line, with the national medical device registration number 20182450063) is used to preheat the output tubing of the analgesic pump until it reaches the predetermined temperature of 37°C. For the control group, after reactivating the analgesic pump's exhaust procedure to remove air from the tubing, the output tubing of the analgesic pump is connected to the epidural catheter without preheating the output tubing using a blood transfusion and infusion warmer, maintaining room temperature (23°C).
No Intervention: Control group; Participants will be assigned to receive 23°C local anesthetic solutions.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maternal fever incidence	The primary outcome measure for this trial is the incidence of maternal fever, as determined by oral temperature readings, throughout the entire labor process. Maternal fever is defined as maternal intrapartum fever with a temperature of 38°C or higher.	Before epidural catheterization, and at 2, 4, and 6 hours after epidural catheterization, and at the end of the second and third stages of labor, and 1 hour postpartum.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
VAS ≤ 3	The Visual Analogue Scale (VAS) is a simple tool for assessing pain intensity. It features a 100mm line with "0" at one end indicating no pain and "10" at the other end representing the worst possible pain. Patients mark their pain level anywhere along the line, providing a continuous measure of their discomfort.	From date of receiving epidural anesthesia until the date of VAS ≤ 3, an average of 30 minutes
Pulse Perfusion Index		Before epidural anesthesia, and at 10 minutes, 20 minutes, and 30 minutes after epidural catheterization.
Maternal and Neonatal Antibiotic Use Rate	Querying the electronic medical record system for antibiotic usage	From the date of randomization until the date of first documented maternal or neonatal antibiotic use, assessed up to 1 month postoperatively.
Incidence of bacteremia	The proportion of positive bacterial culture test results in each group.	From the date of randomization until the date of first documented bacteremia, assessed up to 1 month postoperatively.
Intrapartum hypothermia		Before epidural catheterization, and at 2, 4, and 6 hours after epidural catheterization, and at the end of the second and third stages of labor, and 1 hour postpartum.
Duration of labor		From the onset of labor until the delivery of the placenta, assessed up to 48 hours.
Unplanned cesarean section rate		From date of randomization until the delivery of the placenta, assessed up to 48 hours.
Umbilical Artery pH	After the delivery of the fetus, umbilical arterial blood is drawn to check the pH of the umbilical artery.	up to 48 hours
Apgar score at 1st and 5th minute for newborns	After the delivery of the fetus, the Apgar score is assessed at the 1st and 5th minute post-delivery. The Apgar score is a quick test used to assess the physical condition of a newborn baby immediately after birth. It is performed at one and five minutes after birth, and sometimes at 10 and 20 minutes as well. The score is based on five criteria: Appearance (skin color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), and Respiration (breathing). Each category is scored on a scale from 0 to 2, with 0 indicating the worst condition and 2 the best. The total score ranges from 0 to 10, with a score of 7 to 10 generally considered normal, 4 to 6 indicating the need for some medical assistance, and below 4 requiring immediate medical attention.	From the minute of fetal delivery until 5th minute post-delivery, assessed up to 5 minutes post-delivery.

Collaborators and Investigators

• Sponsor: The First Affiliated Hospital of Soochow University
• Investigators: Principal Investigator: Fuhai Ji, The First Affiliated Hospital of Soochow University

Study record dates

Study Major Dates

• Study Start (Actual): November 30, 2024
• Primary Completion (Estimated): October 1, 2027
• Study Completion (Estimated): October 1, 2027

Study Registration Dates

• First Submitted: November 6, 2024
• First Submitted That Met QC Criteria: November 8, 2024
• First Posted (Actual): November 12, 2024

Study Record Updates

• Last Update Posted (Estimated): September 11, 2025
• Last Update Submitted That Met QC Criteria: September 10, 2025
• Last Verified: September 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Neurologic Manifestations; Nervous System Diseases; Neurobehavioral Manifestations; Body Temperature Changes; Perceptual Disorders; Pathological Conditions, Signs and Symptoms; Signs and Symptoms; Fever; Agnosia; Physiological Effects of Drugs; Peripheral Nervous System Agents; Central Nervous System Depressants; Sensory System Agents; Anesthetics; Anesthetics, Local
• Other Study ID Numbers: 2023367

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: We will share the raw data on ResMan (www.medresman.org.cn). Additionally, the research data will be published in the form of a paper within 2 years after the completion of the clinical trial.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No