Minimal Effective Concentration (EC90) of Ropivacaine

Study Overview
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Brief Summary
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Prospective up and down sequential evaluation of the minimal effective concentration of perineural ropivacaine for 90% success in axillary brachial plexus block with the injection of intravenous dexamethasone or saline placebo during regional anesthesia performance

Detailed Description
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ropivacaine concentration determined by up and down sequential method dexamethasone or saline placebo determined by randomisation

Official Title
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Determination of the Minimal Effective Concentration (EC90) of Ropivacaine in Axillary Brachial Plexus Block With Intravenous Dexamethasone or Saline Injection

Conditions
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Ropivacaine, Dexamethasone, Axillary Brachial Plexus Block, Anesthesia, Conduction

Intervention / Treatment
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* Drug: Intravenous dexamethasone
* Drug: Intravenous saline
* Drug: Perineural ropivacaine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 18 years old or older ASA Score 1,2 et 3 (American Society of Anesthesiologists Score) surgery under axillary brachial plexus block signed information consent Exclusion Criteria: pregnancy and breastfeeding contraindication to regional anesthesia or technical impossibility impaired coagulation delay of surgery to short to allow regional anesthesia dementia or under administrative supervision allergy and contraindication to dexamethasone or ropivacaine total dose of ropivacaine higher than 3 mg / kg (recommended dose for upper limb regional anesthesia) opioids or pain killers abuse or addiction steroids consumption in the past 6 months surgery estimated to be greater than 4 hours anticipated bad observation of treatment patient enrolled in another trial

Ages Eligible for Study
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Minimum Age: 18 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: allocation to one of the 2 arm after randomization
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Intravenous dexamethasone<br>Axillary Brachial Plexus Block with perineural Ropivacaine. Concentration determined by sequential up and down method. Intravenous injection of 8mg/2ml Dexamethasone during the regional anesthesia | Drug: Intravenous dexamethasone<br>* Intravenous injection of 8mg/2ml dexamethasone<br>Drug: Perineural ropivacaine<br>* Perineural injection of 20ml ropivacaine with adjustment of the concentration determined by sequential up and down method<br>|
| Placebo Comparator: Intravenous saline<br>Axillary Brachial Plexus Block with perineural Ropivacaine. Concentration determined by sequential up and down method. Intravenous injection of 2ml Saline 0.9% during the regional anesthesia | Drug: Intravenous saline<br>* Intravenous injection of 2ml Saline 0.9%<br>Drug: Perineural ropivacaine<br>* Perineural injection of 20ml ropivacaine with adjustment of the concentration determined by sequential up and down method<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Surgical Effectiveness of regional anesthesia at 30min | Ability to perform surgery under regional anaesthesia without supplementary anaesthesia | Time of surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| time between regional anesthesia and surgical incision | time between the end of regional anesthesia and the beginning of surgical incision | Time of surgery | 
| Effectiveness of regional anaesthesia on Pin-Prick sense | Defined by a loss of pain sensation at the pinprick test at 30min after the end of regional anaesthesia | Time of anaesthesia | 
| Effectiveness of regional anaesthesia on cold sensation | Defined by a loss of sensation of cold application on skin at 30min after the end of regional anaesthesia | Time of anaesthesia | 
| Effectiveness of regional anaesthesia on motor function | Defined by a paresis at 30min after the end of regional anaesthesia (modified bromage score) | Time of anaesthesia | 
| recovery of regional anesthesia: pain | time to first pain sensation in the surgical wound after the end of regional anaesthesia | first 48h | 
| recovery of regional anesthesia: motor | time to motor recovery of the arm after the end of regional anaesthesia | first 48h | 
| recovery of regional anesthesia: sensory | time to sensory recovery of the arm after the end of regional anaesthesia | first 48h | 
| complication related to regional anesthesia and/or intravenous dexamethasone | any complication during the first 6 month after the surgery | month 6 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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regional anesthesia, dexamethasone, ropivacaine