Dexamethasone as an Adjuvant to Ropivacaine for the Interscalene Brachial Plexus Block

Study Overview
=================
Brief Summary
-----------------
Shoulder surgery is associated with moderate to severe postoperative pain. Interscalene brachial plexus block is considered by many as the gold standard for treating postoperative pain and consists of injecting local anaesthetics close to the nerves of the brachial plexus in the neck. Duration of analgesia is between eight to twelve hours depending on the type of administered drugs. Dexamethasone 4 mg is a steroid routinely injected intravenously in anaesthesia for the prophylaxis of postoperative nausea and vomiting. Recently, different trials have demonstrated that combining 4 to 8 mg of dexamethasone with local anaesthetics for a perineural injection may prolong the duration of analgesia up to 24 hours. In a meta-analysis including 29 trials and 1695 patients, investigators have recently demonstrated through a meta-regression that a dose of 4 mg is sufficient and represents a ceiling dose, without neurological complications. The objective of this multicenter randomised controlled double-blinded trial is to determine the optimal dose of perineural dexamethasone. For that purpose, investigators will include a total of 150 patients divided in 5 groups: local anaesthetics with placebo, or with dexamethasone 1, 2, 3 and 4 mg.

Official Title
-----------------
Dexamethasone as an Adjuvant to Ropivacaine for the Interscalene Brachial Plexus Block: a Dose-finding Study

Conditions
-----------------
Postoperative Pain

Intervention / Treatment
-----------------
* Drug: Placebo
* Drug: Dexamethasone 1 mg
* Drug: Dexamethasone 2 mg
* Drug: Dexamethasone 3 mg
* Drug: Dexamethasone 4 mg
* Drug: Ropivacaine 0.5%


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: patients scheduled for elective shoulder arthroscopy duration of surgery less than 4 hours Exclusion Criteria: allergy to local anaesthetics history of neck surgery history of neck radiotherapy severe respiratory disease diabetic patient chronic pain condition pregnancy patient suffering from cancer patient with addicted disease

Ages Eligible for Study
-----------------
Minimum Age: 18 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
No

Study Plan
=================
How is the study designed?
-----------------

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Control group<br>Patients will receive ropivacaine 0.5% 20 mls with normal saline 0.9% 2 mls | Drug: Placebo<br>* Normal saline 0.9% in 2 mls<br>Drug: Ropivacaine 0.5%<br>* Ropivacaine 0.5% 20 mls<br>|
| Active Comparator: Dex 1<br>Patients will receive ropivacaine 0.5% 20 mls with dexamethasone 1 mg in 2 mls | Drug: Dexamethasone 1 mg<br>* Dexamethasone 1 mg in 2 mls<br>Drug: Ropivacaine 0.5%<br>* Ropivacaine 0.5% 20 mls<br>|
| Active Comparator: Dex 2<br>Patients will receive ropivacaine 0.5% 20 mls with dexamethasone 2 mg in 2 mls | Drug: Dexamethasone 2 mg<br>* Dexamethasone 2 mg in 2 mls<br>Drug: Ropivacaine 0.5%<br>* Ropivacaine 0.5% 20 mls<br>|
| Active Comparator: Dex 3<br>Patients will receive ropivacaine 0.5% 20 mls with dexamethasone 3 mg in 2 mls | Drug: Dexamethasone 3 mg<br>* Dexamethasone 3 mg in 2 mls<br>Drug: Ropivacaine 0.5%<br>* Ropivacaine 0.5% 20 mls<br>|
| Active Comparator: Dex 4<br>Patients will receive ropivacaine 0.5% 20 mls with dexamethasone 4 mg in 2 mls | Drug: Dexamethasone 4 mg<br>* Dexamethasone 4 mg in 2 mls<br>Drug: Ropivacaine 0.5%<br>* Ropivacaine 0.5% 20 mls<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of analgesia |  | 24hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of motor block |  | 24hour | 
| Onset time of action of sensory block |  | 1hour | 
| Onset time of action of motor block |  | 1hour | 
| Equivalent morphine consumption in postanesthetic care unit |  | 4hour | 
| Equivalent morphine consumption on postoperative day 1 |  | 24hour | 
| Pain scores at rest in postanesthetic care unit (visual analogue scale, 0-10) |  | 4hour | 
| Pain scores on movement in postanesthetic care unit (visual analogue scale, 0-10) |  | 4hour | 
| Pain scores at rest on postoperative day 1 (visual analogue scale, 0-10) |  | 24hour | 
| Pain scores on movement on postoperative day 1 (visual analogue scale, 0-10) |  | 24hour | 
| Rate of postoperative nausea and vomiting (PONV) | Presence of PONV (YES/NO) | 24hour | 
| Rate of pruritus | Presence of pruritus (YES/NO) | 24hour | 
| Satisfaction score on postoperative day 1 (visual analogue scale, 0-10) |  | 24hour | 
| Glycemia in postanesthetic care unit (mmol/l) |  | 4hour | 
| Rate of infection | Presence of infection (YES/NO) | 24hour | 
| Rate of infection | Presence of infection (YES/NO) | 7 days | 
| Rate of paresthesia | Presence of paresthesia (YES/NO) | 7 days | 
| Rate of muscle weakness | Presence of muscle weakness (YES/NO) | 7 days |