tDCS for Reducing the Incidence of OEI After Cesarean Section

June 30, 2026 updated by: Chaochao Zhong, Affiliated Hospital of Nantong University

Study on the Preventive and Therapeutic Effects and Mechanism of Transcranial Direct Current Stimulation on Morphine-Induced Itching After Cesarean Section: A Randomized Clinical Controlled Trial

Cesarean section is the most common obstetric surgery worldwide. Epidural anesthesia has become the preferred anesthesia method for cesarean sections due to its definite analgesic effect and minimal impact on mother and baby. To ensure postoperative analgesia, intrathecal administration of morphine (the preferred opioid for obstetric intrathecal analgesia) is a routine clinical protocol, but morphine-induced postoperative pruritus is a common adverse reaction. A study targeting the cesarean section population confirmed that the incidence of pruritus after epidural morphine administration is as high as 40%-75%.Transcranial direct current stimulation (tDCS) can enhance the activity of GABAergic inhibitory interneurons in the spinal dorsal horn through the cortical-spinal descending pathway, reverse the inhibitory effect of morphine on them, and restore negative feedback regulation of itch-specific GRPR⁺ neurons; at the same time, it downregulates the phosphorylation level and membrane expression of μ-opioid receptors in the spinal dorsal horn, weakening the receptor activation efficiency of morphine. On the other hand, tDCS can reduce peripheral nerve excitability, decrease mast cell degranulation in the skin, and reduce the release of histamine and tryptase; simultaneously, it inhibits the activation of glial cells in the spinal cord/cortex, decreases the secretion of pro-inflammatory factors such as TNF-α and IL-6, and blocks the vicious cycle of 'inflammation-receptor upregulation-itch exacerbation,' thereby reducing the occurrence of itch.This study aims to explore the effect of transcranial direct current stimulation (tDCS) on the incidence of morphine-induced itching after cesarean section by inhibiting the central itch perception circuits in cesarean section patients and antagonizing the disinhibitory effects mediated by μ-opioid receptors in the spinal dorsal horn.

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

104

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 18-40 years, gestational age 37-41 weeks, singleton full-term pregnancy;
  • Planned elective or emergency cesarean section, using epidural anesthesia (0.1~0.2 mg/kg of morphine administered intrathecally during surgery);
  • American Society of Anesthesiologists (ASA) classification I-III;
  • Conscious and able to cooperate to complete scale assessments, serum sample collection, and postoperative follow-up;
  • Voluntarily participate in the study and sign the informed consent form.

Exclusion Criteria:

  • Presence of contraindications for tDCS (such as skull defects, intracranial metal implants, history of epilepsy, coagulation disorders);
  • Allergy to opioids or a history of severe OEI;
  • Presence of skin diseases (such as eczema, urticaria), liver diseases (cholestasis), mental disorders, or cognitive impairments;
  • Coexisting pregnancy complications (preeclampsia, gestational diabetes, autoimmune diseases);
  • Use of medications within the past week that may affect itch assessment, such as antihistamines, 5-HT3 receptor antagonists, or anti-inflammatory drugs.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Sham Comparator: control group (sham stimulation group)
Device: Transcranial direct current stimulation (placebo stimulation)
Sham stimulation group (control group): The anode of the electrical stimulator is placed on the left dorsolateral prefrontal cortex (F3 region) and the cathode on the right mastoid area. A current of 1.5 mA is applied only during the first 30 seconds after the start of stimulation, after which the current is reduced to 0 mA. All other procedures (electrode placement, stimulation duration, intervention frequency) are the same as those in the experimental group.
Experimental: Case group (tDCS group)
Device: Transcranial direct current stimulation
Patients in the transcranial direct current stimulation (tDCS) group had the anode of the tDCS device placed on the left dorsolateral prefrontal cortex (F3 area) and the cathode on the right mastoid. The tDCS was administered on the day of surgery (starting within 5 minutes after delivery of the fetus and ending upon transfer to the PACU after surgery). The current intensity was 1.5 mA.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Incidence of itching within 24 hours after surgery (defined as VAS itching score ≥1)
Time Frame: 24 hours after surgery
The VAS scoring standard for the degree of itching is a tool used to assess the severity of itching. VAS stands for Visual Analog Scale. The following are the standards for VAS scoring of itching severity: 0 points: No itching. 1-3 points: Mild itching, does not affect daily life. 4-6 points: Moderate itching, somewhat affects daily life. 7-9 points: Severe itching, seriously affects daily life, requires active treatment. 10 points: Extremely severe itching, unbearable, requires immediate treatment.
24 hours after surgery

Secondary Outcome Measures

Outcome Measure
Time Frame
Incidence of itching at 12 and 48 hours postoperatively; VAS scores for itching at each time point; duration of itching and time of peak appearance
Time Frame: 12 hours post-operation and 48 hours post-operation
12 hours post-operation and 48 hours post-operation
Number of times the analgesic pump was pressed and the doses of additional morphine within 48 hours postoperatively; VAS pain scores at 12, 24, and 48 hours postoperatively
Time Frame: 12 hours, 24 hours, and 48 hours after surgery
12 hours, 24 hours, and 48 hours after surgery
Maternal adverse reactions (nausea and vomiting, drowsiness, dizziness, ear pain, skin erythema) incidence; neonatal 1-minute and 5-minute Apgar scores, birth weight, complications within 72 hours (jaundice, shortness of breath, feeding difficulties)
Time Frame: Within 72 hours after surgery
Within 72 hours after surgery
Preoperative and postoperative 24h serum histaminelevels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery
Preoperative and postoperative 24h trypsin-like enzymelevels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery
Preoperative and postoperative 24h TNF-α levels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery
Preoperative and postoperative 24h IL-6 levels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery
Preoperative and postoperative 24h β-endorphin levels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery
Preoperative and postoperative 24h gastrin-releasing peptide precursor (ProGRP) levels
Time Frame: 24 hours before surgery and 24 hours after surgery
24 hours before surgery and 24 hours after surgery

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Affiliated Hospital of Nantong University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

June 15, 2026

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

February 20, 2027

Study Registration Dates

First Submitted

April 23, 2026

First Submitted That Met QC Criteria

April 29, 2026

First Posted (Actual)

May 6, 2026

Study Record Updates

Last Update Posted (Actual)

July 2, 2026

Last Update Submitted That Met QC Criteria

June 30, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2026-K102-01

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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