Evaluation of the Stress Response in Bariatric Surgery With and Without the Use of Opioids

July 31, 2026 updated by: Panagiotis Chatzistavridis, G.Gennimatas General Hospital

The goal of this clinical trial is to compare Opioid Free and Opioid Based Anaesthesia in patients undergoing sleeve gastrectomy. The main questions it aims to answer are:

  • Will the total dose of intraoperative opioid be reduced?
  • Will there be difference in pain scores between groups? Participants will be managed with the Nociceptive Level Index algorithm to guide intraoperative analgesia.

The Opioid Free Anaesthesia Group will be administered the Multimix infusion (Magnesium sulfate, dexmedetomidine, ketamine). The Opioid Based Anaesthesia Group will receive fentanyl as a bolus dose and remifentanil infusion.

Rescue fentanyl bolused will be injected as appropriate according to nociceptive level (NOL) values.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Opioid Free Anaesthesia has attracted the attention of clinicians since the outbreak of the opioid pandemic in the USA. It has been correlated with less intraoperative and postoperative opioid use. The Nociceptive Level Index algorithm allows for intraoperative monitoring of the nociceptive pathways and targeted pain management. Furthermore, it is known that morbidly obese patients may benefit from opioid sparing techniques.

Our aim is to investigate the effect of Opioid Free versus Opioid Based Anesthesia on postoperative pain in patients undergoing sleeve gastrectomy.

In this randomized, double blind clinical trial, patients will be allocated into two groups based on intraoperative pain management. Apart from recording postoperative pain scores, blood samples will be collected intraoperatively to evaluate the stress response among the two groups.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
70

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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 Locations

  • Greece
      • Athens, Greece, 11527
        • G.Gennimatas General Hospital

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 75 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age >18y and <75y
  • morbid obesity confirmed diagnosis
  • American Society of Anesthesiologists (ASA) II-III
  • elective laparoscopic sleeve gastrectomy surgery
  • signed informed consent

Exclusion Criteria:

  • bradycardia, bundle branch block, hypotension, postural hypotension
  • obstructive sleep apnoea
  • history of depression
  • chronic corticosteroid use or intraoperative administration of more than 8mg of prednisolone or equivalent
  • refusal to participate

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

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Opioid Based Anaesthesia

This arm will receive:

  • 2 mcg/kg fentanyl in 10 ml volume
  • 0.2 mL/kg/h remifentanil infusion
  • 0.1 mg/kg morphine
Drug: Opioid based anesthesia
  • 2 mcg/kg fentanyl in 10 ml volume
  • 0.2 mL/kg/h remifentanil infusion
  • 0.1 mg/kg morphine. Except for standard analgesic strategies, both groups will receive fentanyl as a rescue dose (1mcg/kg) based on a nociceptive level value > 25 or elevation of Heart Rate and/or Blood Pressure >20%.

Placebo infusions of normal saline will be prepared to enable blinding.
Active Comparator: Opioid Free Anaesthesia

This arm will receive

  • 40 mg/kg magnesium sulfate in 100 ml N/S infusion
  • 0.4 mcg/kg dexmedetomidine, max total dose 50mcg in 50 ml N/S infusion
  • 0.3 mg/kg ketamine in 10 ml volume
  • 0.2 ml/kg of the Multimix regimen in 100 ml N/S infusion as a bolus (The Multimix regimen consists of 50mcg dexmedetomidine, 500 mg lidocaine and 50mg ketamine).
  • 0.2 ml/kg/h of the Multimix regimen in 100 ml N/S infusion as a continuous infusion
Drug: Opioid Free Anaesthesia
  • 40 mg/kg magnesium sulfate in 100 ml N/S infusion
  • 0.4 mcg/kg dexmedetomidine, max total dose 50mcg in 50 ml N/S infusion
  • 0.3 mg/kg ketamine in 10 ml volume
  • 0.2 ml/kg of the Multimix regimen in 100 ml N/S infusion as a bolus (The Multimix regimen consists of 50mcg dexmedetomidine, 500 mg lidocaine and 50mg ketamine).
  • 0.2 ml/kg/h of the Multimix regimen in 100 ml N/S infusion as a continuous infusion. Except for standard analgesic strategies, both groups will receive fentanyl as a rescue dose (1mcg/kg) based on a nociceptive level value > 25 or elevation of Heart Rate and/or Blood Pressure >20%.

Placebo infusions of normal saline will be prepared to enable blinding.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Postoperative Visual Analogue Scale (VAS) score
Time Frame: 6 hours after surgery
The patient will be interviewed regarding postoperative pain using Visual Analogue Scale, ranging from 0 to 10, where 0 means "no pain" and 10 means "worst pain imaginable
6 hours after surgery

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
First demand for supplementary analgesia
Time Frame: Up to 24 hours postoperatively
The time to the first demand for supplementary analgesia will be recorded for every patient enrolled.
Up to 24 hours postoperatively
Postoperative VAS score
Time Frame: 24 hours
The patient will be interviewed regarding postoperative pain using Visual Analogue Scale, ranging from 0 to 10, where 0 means "no pain" and 10 means "worst pain imaginable
24 hours
Perioperative trend of Adrenaline
Time Frame: At baseline, at the end of the operation, 24 hours after surgery
Blood will be collected to measure the plasma adrenaline levels
At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Noradrenaline
Time Frame: At baseline, at the end of the operation, 24 hours after surgery
Blood will be collected to measure the plasma Noradrenaline levels
At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Cortisol
Time Frame: At baseline, at the end of the operation, 24 hours after surgery
Blood will be collected to measure the plasma Cortisol levels
At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Dopamine
Time Frame: At baseline, at the end of the operation, 24 hours after surgery
Blood will be collected to measure the plasma Dopamine levels
At baseline, at the end of the operation, 24 hours after surgery

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
G.Gennimatas General Hospital

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
Aristotle University Of Thessaloniki

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
January 1, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
July 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 11, 2023

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 21, 2023

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
March 3, 2023

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
August 3, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 31, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 31235/1.12.2022

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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