OFA - Opioid Free Anesthesia

Study Overview
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Brief Summary
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Opioids have been used for analgesia since many years, but despite potent analgesia they are also associated to side effects, including opioid induced Hyperalgesia (OIH). OIH in the surgical setting is debated, and may predispose patients to higher analgesic consumption in the preoperative period, and peripheral and central sensitization. The aim of the study is to compare remifentanil-based vs non opioid analgesia (clonidine, lidocaine, ketamine) for intraoperative management of patients undergoing laparoscopic left hemicolectomy, with the hypothesis that non- opiod treated patients will have lower morphine consumption in the first 24 hours after surgery. Peripheral and central hyperalgesia will be tested with Von Frey hairs and pin-prick to evaluate acute CNS (Central Nervous System) sensitization after surgery. Acute and persistent (1 and 3 months) pain will be registered, together with any side effect and parameters of surgical rehabilitation.

Official Title
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Study Protocol OFA: Opioid-Free Anesthesia.

Conditions
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Postoperative Pain

Intervention / Treatment
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* Drug: Remifentanil
* Drug: Ketamine
* Drug: Lidocaine
* Drug: Clonidine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: left hemicolectomy signed informed consent >18 ys Exclusion Criteria: >90 ys <18 ys no consent pregnancy psychiatric disease cardiac failure, aortic or mitral valve severe stenosis kidney or hepatic failure atrio-ventricular type II block immunodepression emergency surgery ICU admittance drug or alcohol abuse chronic pain

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 90 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
Interventional Model Description: randomized double blind trial
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: opioid<br>remifentanil 0,15-0,25 mcg/kg/h | Drug: Remifentanil<br>* continuous infusion intraop<br>|
| Experimental: opioid free<br>ketamine bolus 0,5 mg/kg + infusion 0,25 mg/kg/h lidocaine bolus 1 mg/kg + infusion 1 mg/kg/h clonidine 4 mcg/kg | Drug: Ketamine<br>* bolus 0,5 mg/kg + infusion 0,25 mg/kg/h<br>Drug: Lidocaine<br>* lidocaine bolus 1 mg/kg + infusion 1 mg/kg/h<br>Drug: Clonidine<br>* clonidine 4 mcg/kg<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| analgesic consumption | morphine mg by PCA (Patient Controlled Analgesia) | 24 HOURS | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| side effects | nausea and vomiting, ileus, itching, shiver, hypotension, bradycardia, sedation | 4 days after surgery | 
| Pain Score on the Visual Analog Scale | VAS (Visual Analog Scale) | 3 months | 
| peripheral sensitization | assessment of primary hyperalgesia by Von Frey Filaments at 24 hours | 24 hours | 
| central sensitization | assessment of secondary hyperalgesia by pin-prick test at 24 hours | 24 hours |