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

Study Overview
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Brief Summary
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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
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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.

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

Conditions
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Opioid Use, Unspecified, Bariatric Surgery Candidate

Intervention / Treatment
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* Drug: Opioid Free Anaesthesia
* Drug: Opioid based anesthesia


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Opioid Based Anaesthesia<br>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<br>* 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.<br>|
| Active Comparator: Opioid Free Anaesthesia<br>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<br>* 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.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 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 | 6 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| First demand for supplementary analgesia | The time to the first demand for supplementary analgesia will be recorded for every patient enrolled. | 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 | 24 hours | 
| Perioperative trend of Adrenaline | 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 | 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 | 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 | Blood will be collected to measure the plasma Dopamine levels | At baseline, at the end of the operation, 24 hours after surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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morbid obesity, opioid free anaesthesia, nociception level, analgesia, bariatric surgery