Effect of MGRNOX-Guided General Anesthesia on Opioid Consumption in Patients

December 10, 2025 updated by: Peking University Shenzhen Hospital

Effect of MGRNOX-Guided General Anesthesia on Opioid Consumption in Patients:A Randomized Controlled Trial

  1. Pain management is a crucial part of general anesthesia surgery. Nociception monitoring can help anesthesiologists better titrate the use of intraoperative analgesic drugs, especially the opioid.
  2. Although a variety of nociception monitoring devices have been developed to date, there is not a specific monitoring indicator that serves as the "gold standard" to objectively guide analgesic management in general anesthesia.
  3. The MGRNOX index, which is derived from electroencephalogram (EEG), is used to reflect the correlation between noxious stimuli and opioid analgesics in a state of general anesthesia by converting and quantifying the EEG signals collected by the instrument. However, no studies have so far verified the effect of the MGRNOX index-guided analgesic management of general anesthesia on the consumption of opioids in patients.
  4. This study aims to explore the effect of MGRNOX index-guided general anesthesia on opioid consumption in patients undergoing laparoscopic cholecystectomy and the primary hypothesis of our study is that using the MGRNOX index to guide intraoperative pain management during general anesthesia can significantly reduce the consumption of remifentanil during the surgery.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

Pain management is a critical component of perioperative anesthesia. Traditionally, anesthesiologists adjust analgesic dosages based on intraoperative heart rate or blood pressure, relying heavily on personal clinical experience. This approach often leads to over- or under-administration of analgesics. Currently, opioids remain the primary analgesics used in general anesthesia. Excessive opioid doses can result in postoperative hyperalgesia, delayed recovery, respiratory and circulatory depression, and increased hepatic/renal burden. Conversely, insufficient opioid doses may lead to inadequate analgesia, intraoperative hemodynamic instability, postoperative pain, and agitation.

In recent years, various nociception monitoring devices (e.g., SPI, ANI, qNOX) have been developed to quantify intraoperative nociception, assisting anesthesiologists in optimizing analgesic administration to achieve precision and balanced anesthesia. Studies suggest that nociception-guided analgesia during general anesthesia surgery reduces opioid consumption, alleviates postoperative pain, and improves hemodynamic stability compared to traditional standardized management. However, due to the limitations of existing indices, no specific parameter has yet been established as a gold standard for objectively reflecting intraoperative nociception levels.

The MGRNOX index, a China-developed metric based on central nervous system monitoring, derives from processed and quantified electroencephalographic (EEG) signals under general anesthesia to reflect a patient's analgesic state. As clinical evidence for MGRNOX remains limited and its impact on intraoperative opioid usage remains unvalidated, the investigators designed this randomized controlled trial to investigate whether MGRNOX-guided general anesthesia reduces opioid consumption during laparoscopic cholecystectomies. Our primary hypothesis is that intraoperative MGRNOX-guided analgesia will significantly decrease remifentanil requirements.

Study Type

Interventional

Enrollment (Estimated)

112

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

Study Locations

  • China
    • Guangdong
      • Shenzhen, Guangdong, China
        • Recruiting
        • Peking University Shenzhen Hospital
        • 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 years old and < 65 years old；
  • American Society of Anesthesiologists (ASA) class I-II；
  • Scheduled to undergo elective laparoscopic cholecystectomy undergeneral anesthesia （without epidural anesthesia, local blocks, or infiltration）

Exclusion Criteria:

  • Pregnancy or lactation period；
  • BMI ≥35 kg/m² or <18.5 kg/m²；
  • Anticipated difficult airway；
  • Previous diagnosis of hypertension；
  • History of drug or alcohol abuse within the past 6 months；
  • Preoperative acute or chronic pain history (routine preoperative use of opioid or non-opioid analgesics), peripheral or central nervous system-related disorders；
  • Definitively diagnosed psychiatric disorders or other neuropsychiatric conditions severely affecting cognitive judgment, history of psychotropic medication use；
  • Allergy or intolerance to anesthetic agents；
  • Baseline mean arterial pressure (MAP) <60 mmHg or >120 mmHg; baseline heart rate (HR) <45 bpm or >90 bpm (Baseline values defined as first measurement taken in the ward after admission)；
  • History of severe underlying diseases (untreated or ongoing peripheral/central cardiovascular diseases, severe hepatic disorders with elevated bilirubin/INR or hypoalbuminemia, severe renal diseases with elevated creatinine, severe pulmonary diseases potentially causing acute respiratory failure or persistent dyspnea)；
  • Implanted pacemaker, chronic arrhythmia, preoperative use of prescribed anticholinergics, α2-adrenergic agonists, beta-1 adrenergic antagonists, or antiarrhythmic medications.

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: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Standard Clinical Care Group
After anesthesia induction, the remifentanil plasma target concentration was adjusted intraoperatively based on mean arterial pressure and heart rate.
Device: Standard Clinical Care
After anesthesia induction, if hypertension (MAP > 100 mmHg) or tachycardia (heart rate > 90 bpm) persists for more than 2 minutes, remifentanil target-controlled infusion levels were increased in steps of 0.5 ng/ml.If there is no response to remifentanil or the MAP and HR exceed a certain threshold, then urapidil or esmolol will be administered.For hypotension (50 mmHg < MAP ≤ 60 mmHg) persisting for more than 2 minutes, remifentanil target-controlled infusion levels were lowered in steps of 0.5 ng/ml (lowest target plasma concentration that was allowed is 1 ng/ml), and 4μg of norepinephrine were given. If MAP ≤ 50 mmHg, remifentanil target-controlled infusion levels were lowered in steps of 0.5 ng/ml(lowest target plasma concentration that was allowed is 1 ng/ml), and 8μg of norepinephrine were given.
Experimental: MGRNOX index-guided analgesia group
After anesthesia induction, the remifentanil plasma target concentration was adjusted intraoperatively to maintain the MGRNOX index within 30-50,but mean arterial pressure and heart rate were additionally monitored and considered.
Device: MGRNOX index-guided analgesia
After anesthesia induction, the remifentanil plasma target concentration was adjusted intraoperatively to maintain the MGRNOX index between 30 and 50,but MAP and HR also were considered .In case the MGRNOX index was below 30 for more than 1 minute, remifentanil target-controlled infusion levels were lowered in steps of 0.5 ng/ml , whereas in case of a value greater than 50 for more than 1 minute, remifentanil target-controlled infusion levels were increased in steps of 0.5 ng/ml.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
opioids
Time Frame: From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.
Intraoperative remifentanil consumption, the dose unit is expressed as μg/kg/min.
From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
pain score
Time Frame: One hour after extubation
The numerical rating scale (NRS，11-point scale, with 0 indicating no pain and 10 indicating the most severe pain) after extubation was evaluated every 15 minutes
One hour after extubation
Incidence of unexpected events
Time Frame: From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.
severe hypotension：MAP<50mmHg，severe hypertension：MAP>120mmHg，tachycardia：HR>120beats/min，bradycardia：HR<40 beats/min，hypoxemia：SpO2≤92%，intraoperative awareness：Patients under general anesthesia showed a conscious state during the operation and could recall the surgery-related events that occurred during the operation postoperatively
From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.
incidence of complications
Time Frame: during PACU（at least 1 hour)
postoperative complications during PACU：Nausea and vomiting，agitation，delirium
during PACU（at least 1 hour)
the consumption of sedative drug
Time Frame: From the beginning of anesthesia induction until 5 minutes before the end of the surgery.
Intraoperative propofol consumption, the dose unit is expressed as mg/kg/h
From the beginning of anesthesia induction until 5 minutes before the end of the surgery.
the consumption of vasoactive drug
Time Frame: From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.
Intraoperative vasoactive drugs consumption，involved drug type and dosage
From the beginning of anesthesia induction until surgical procedure end（time of final wound closure）,assessed during surgery.

Collaborators and Investigators

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

Sponsor

Peking University Shenzhen Hospital

Investigators

  • Principal Investigator: Tao Luo, MD,PHD, Peking University Shenzhen Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

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 (Actual)

June 28, 2025

Primary Completion (Estimated)

May 30, 2026

Study Completion (Estimated)

May 30, 2026

Study Registration Dates

First Submitted

May 18, 2025

First Submitted That Met QC Criteria

May 26, 2025

First Posted (Actual)

June 4, 2025

Study Record Updates

Last Update Posted (Actual)

December 18, 2025

Last Update Submitted That Met QC Criteria

December 10, 2025

Last Verified

May 1, 2025

More Information

Terms related to this study

Other Study ID Numbers

  • 2025-024

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

product manufactured in and exported from the U.S.

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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