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NCT Number: NCT05752799

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

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.

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Key information

Conditions

Opioid Use, Unspecified Agnosia Bariatric Surgery Candidate Body Weight Nervous System Diseases Neurobehavioral Manifestations Neurologic Manifestations Nutrition Disorders Nutritional and Metabolic Diseases Obesity Obesity, Morbid Overnutrition Overweight Pathological Conditions, Signs and Symptoms Perceptual Disorders Signs and Symptoms

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Opioid Free Anaesthesia

Drug
  • 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 Anesthesia

Drug
  • 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.

Primary outcomes

  1. 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

Secondary outcomes

  1. 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.

  2. 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

  3. 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

  4. 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

  5. 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

  6. 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

Sponsors and collaborators

Lead sponsor

G.Gennimatas General Hospital

Other

Collaborators

  • Aristotle University Of Thessaloniki

Registry information

Important dates

Study start
2023
Primary completion
2026
Study completion
2027
First posted
Mar 3, 2023
Registry last updated
Apr 28, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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