Opioid Use, UnspecifiedNCT05752799
Evaluation of the Stress Response in Bariatric Surgery With and Without the Use of Opioids
A study testing Opioid Free Anaesthesia and Opioid based anesthesia in people with Opioid Use, Unspecified and Bariatric Surgery Candidate, run by G.Gennimatas General Hospital at 1 site in Greece.
Trial summary
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… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Opioid Use, Unspecified, Bariatric Surgery Candidate
- What is being tested?
- Opioid Free Anaesthesia and Opioid based anesthesia
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 70 participants
- Where
- 1 siteGreece
- Study dates
- 1 Jan 2023to 1 Jun 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age >18y and <75y
- morbid obesity confirmed diagnosis
- American Society of Anesthesiologists (ASA) II-III
- elective laparoscopic sleeve gastrectomy surgery
- signed informed consent
Who cannot join
- 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
Trial locations and contacts
1 site in 1 country.
About this study
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.
Read more
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.
Read the 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.
- Being tested
- Opioid Free Anaesthesia, Opioid based anesthesia
- Keywords
- morbid obesity, opioid free anaesthesia, nociception level, analgesia, bariatric surgery
- Medical subject headings
- Obesity, Morbid, Agnosia
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Opioid Free AnaesthesiaDrug
- 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.
Opioid based anesthesiaDrug
- 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.
| Study group | Role | What they receive |
|---|---|---|
| Opioid Based Anaesthesia | Active comparator | This arm will receive:
* 2 mcg/kg fentanyl in 10 ml volume
* 0.2 mL/kg/h remifentanil infusion
* 0.1 mg/kg morphine Receives: Drug: Opioid based anesthesia |
| Opioid Free Anaesthesia | Active comparator | 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 Receives: Drug: Opioid Free Anaesthesia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Postoperative Visual Analogue Scale (VAS) score
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
Measured: 6 hours after surgery
Secondary outcomes (6)
First demand for supplementary analgesia
The time to the first demand for supplementary analgesia will be recorded for every patient enrolled.
Measured: Up to 24 hours postoperatively
Postoperative VAS score
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
Measured: 24 hours
Perioperative trend of Adrenaline
Blood will be collected to measure the plasma adrenaline levels
Measured: At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Noradrenaline
Blood will be collected to measure the plasma Noradrenaline levels
Measured: At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Cortisol
Blood will be collected to measure the plasma Cortisol levels
Measured: At baseline, at the end of the operation, 24 hours after surgery
Perioperative trend of Dopamine
Blood will be collected to measure the plasma Dopamine levels
Measured: At baseline, at the end of the operation, 24 hours after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Mar 2023
- Study start1 Jan 2023
- Primary completion1 Jul 2026
- Study completion1 Jun 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Opioid Use, UnspecifiedStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 70 participants (estimated)
Sponsor and investigators
- Lead sponsor
- G.Gennimatas General Hospital
- Sponsor type
- University, hospital or other
- Collaborators
- Aristotle University Of Thessaloniki
- Responsible party
- Principal investigator, Panagiotis Chatzistavridis, G.Gennimatas General Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05752799
- Sponsor's protocol ID
- 31235/1.12.2022
- Status last verified
- Jul 2026
- First submitted
- 11 Feb 2023
- Last updated
- 3 Aug 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 3 Aug 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of the Stress Response in Bariatric Surgery With and Without the Use of Opioids
- ClinicalTrials.gov ID
- NCT05752799
- Acronym / sponsor ID
- 31235/1.12.2022
- Keywords
- morbid obesity, opioid free anaesthesia, nociception level, analgesia, bariatric surgery
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 70 participants (estimated)
- Lead sponsor
- G.Gennimatas General HospitalUniversity, hospital or other
- Collaborators
- Aristotle University Of Thessaloniki
- Study start
- 1 Jan 2023 (actual)
- Primary completion
- 1 Jul 2026 (actual)
- Study completion
- 1 Jun 2027 (estimated)
- First posted
- 3 Mar 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Opioid Based Anaesthesia | Active comparator | Drug: Opioid based anesthesiaThis arm will receive: * 2 mcg/kg fentanyl in 10 ml volume * 0.2 mL/kg/h remifentanil infusion * 0.1 mg/kg morphine |
| Opioid Free Anaesthesia | Active comparator | Drug: Opioid Free AnaesthesiaThis 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 |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- Age >18y and <75y
- morbid obesity confirmed diagnosis
- American Society of Anesthesiologists (ASA) II-III
- elective laparoscopic sleeve gastrectomy surgery
- signed informed consent
Key exclusion criteria (5 listed)
- 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
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| 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. | Drug | Opioid Free Anaesthesia |
| 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. | Drug | Opioid Based Anaesthesia |
Primary outcome
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 secondary outcomes
First demand for supplementary analgesia
Time frame: Up to 24 hours postoperatively
Postoperative VAS score
Time frame: 24 hours
Perioperative trend of Adrenaline
Time frame: 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
Perioperative trend of Cortisol
Time frame: 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
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 3 Aug 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Opioid Free Anaesthesia and Opioid based anesthesia in people with Opioid Use, Unspecified and Bariatric Surgery Candidate, run by G.Gennimatas General Hospital at 1 site in Greece.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 5 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 3 Aug 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Greece. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Postoperative Visual Analogue Scale (VAS) score (time frame: 6 hours after surgery). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 3 Aug 2026.