Benefits of Opioid Free Anesthesia on Morphine Consumption in Gastric Bypass

Study Overview
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Brief Summary
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Opioid free anesthesia is a recent anesthesia technique with the aim to avoid peroperative use of morphinics to allow a diminution of secondary morphinics effects in the postoperative period. There is no robust data on the real benefits of such procedures. Obese patients are particular at risk of secondary effects of opioids. The aim of our study is to compare opioid free anesthesia to multimodal anesthesia on postoperative morphine consumption after a laparoscopic gastric bypass.

Detailed Description
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The aim of the study is to study the impact of an opioid free anesthesia protocol on the postoperative morphine consumption in laparoscopic gastric bypass compared to a multimodal anesthesia protocol. 183 morbidly obese patients (Body mass index >40Kg/m2 or >35kg/m2 AND/OR diabete mellitus AND/OR sleep apnea syndrome AND/OR arterial hypertension. A randomization will allocate two groups of 100 patients in: Group 1: Multimodal anesthesia without opioids Group 2: Multimodal anesthesia with opioid The patient, the anesthesist and the data evaluator will be all blinded about the allocation of the patient.

Official Title
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Impact of an Opioid Free Anesthesia Protocol Compared to Multimodal Anesthesia on Postoperative Morphine Consumption in an Enhanced Recovery After Gastric Bypass Surgery Protocol: a Prospective, Double Blind Study

Conditions
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Analgesics, Opioid

Intervention / Treatment
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* Drug: Dexmedetomidine Injection [Precedex]
* Drug: Remifentanil


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: American Society of anesthesia score (ASA) 2-3 Scheduled for a laparoscopic gastric bypass surgery Exclusion Criteria: Patient refusal Medical diseases: Cardiac arrhythmia like atrioventricular block 2nd or 3rd degree, pacemaker, arterial hypotension, severe bradycardia, cerebrovascular pathology, renal and/or hepatic insufficiency Previous bariatric surgery Allergy to any medication used during the surgery

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Opioid free anesthesia<br>Dexmedetomidine 0,5 microgrammes/kg of ideal body weight (IBW) + magnesium 40 mg/kg of total body weight (TBW) in 10 minutes Dexmedetomidine 0,4- 0,8 microgrammes/kg of IBW/h;Lidocaine 2% 49ml+ Ketamine 50mg: 1ml/10kg of IBW/ hour;Ketamine 25 mg;lidocaïne 1,5 mg/kg IBW;Propofol 2mg/kgTBW;Rocuronium 1,2 mg/kg IBW;Cefazoline 2g if >120 kg, 3g if >120Kg;Paracetamol 15 mg/ KgTBW;Diclofenac 75 mg;Dexamethasone 10 mg;Ondansetron 4 mg;Sevorane;dexmedetomidine: 0,4-0,8 microgramme/kg/h;Rocuronium 0,1 mg/kg of IBW if posttetanic count>1/10;Atropine 0,5 mg if heart rate < 40/min;Ephedrine 5mg in Arterial mean pressure < 20% of basal value;Nicardipine 0,5 mg if Arterial mean pressure > 20% of basal value Emergence Stop dexmedetomidine;Stop sevorane;1 ml of NaCL 0,9%;Suggamadex 4 mg/ kg of IBW+ 4mg/kg of 40% ABW Post-anesthesia:Lidocaïne 2% 49ml + Ketamine 50 mg: 0,5 ml/ 10 kg IBW;Paracetamol 1g/6h;Diclofenac 75mg/12h;Morphine patient controlled analgesia: 1 mg/5 min, maximum 20mg/ 4 hours | Drug: Dexmedetomidine Injection [Precedex]<br>* dexmedetomidine or remifentanil during laparoscopic gastric bypass<br>|
| Experimental: Multimodal anesthesia<br>magnesium 40 mg/kg of total body weight (TBW) in 10 minutes Remifentanil 0,2-0,4 microgrammes/kg/min of ideal body weight; Saline 0,9%: Infusion at 1ml/10kg of ideal body weight/ hour;Ketamine 25 mg;lidocaïne 1,5 mg/kg IBW;Propofol 2mg/kgTBW;Rocuronium 1,2 mg/kg IBW;Cefazoline 2g if >120 kg, 3g if >120Kg;Paracetamol 15 mg/ Kg TBW;Diclofenac 75 mg;Dexamethasone 10 mg;Ondansetron 4 mg;Sevorane;remifentanil 0,2-0,4 microgrammes/kg/min;Rocuronium 0,1 mg/kg of IBW if posttetanic count>1/10;Atropine 0,5 mg if heart rate < 40/min;Ephedrine 5mg in Arterial mean pressure < 20% of basal value;Nicardipine 0,5 mg if Arterial mean pressure > 20% of basal value Emergence Stop remifentanil;Stop sevorane;1 ml of morphine 10mg/ml;Suggamadex 4 mg/ kg of IBW+ 4mg/kg of 40% ABW Post-anesthesia:Salne 50ml: 0,5 ml/ 10 kg IBW;Paracetamol 1g/6h;Diclofenac 75mg/12h;Morphine patient controlled analgesia: 1 mg/5 min, maximum 20mg/ 4 hours | Drug: Remifentanil<br>* dexmedetomidine or remifentanil during laparoscopic gastric bypass<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Total Morphine consumption | total morphine consumption from the PACU arrival to the 24 h post-surgery | 24 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual analog scale |  | Post Anesthesia Care Unit admission (Hour 0), Hour +4, Hour +24 | 
| Morphine consumption |  | Post Anesthesia Care Unit admission (Hour 0), Hour +4 | 
| Quality of Recovery 40 score | Recovery scale: From 40 (worst recovery) to 200 (Best Recovery) | operative Day -1, Operative day +1, operative day +30 | 
| Hypoxemia | SpO2 < 90% on 2 liters of nasal Oxygen | up to patient discharge | 
| Postoperative Nausea and vomiting |  | Post Anesthesia Care Unit admission (Hour 0), Hour +4, Hour +24 | 
| Need of Antiemetics |  | Up to patient discharge | 
| Bradycardia and use of atropine |  | Up to patient discharge | 
| Readmissions rate | Admission of the patient in hospital during the first 30 postoperative days | Up to 30 days |