Intravenous Dexamethasone to Increase the Analgesic Duration of Interscalene Block

Study Overview
=================
Brief Summary
-----------------
Interscalene brachial plexus block provides excellent but time limited analgesia. Intravenous dexamethasone increases the analgesic duration of a single-shot interscalene block with ropivacaine for shoulder arthroscopic surgery. We want to evaluate the effect of two different doses (dexamethasone 10 mg i.v. vs 4 mg i.v. vs placebo) on the analgesic duration of a single-shot inter scalene block. Our study hypothesis is that dexamethasone 4 mg i.v. is equivalent to dexamethasone10 mg i.v. in prolonging the analgesic duration of a single-shot interscalene block with ropivacaine.

Detailed Description
-----------------
75 patients will be randomly assigned to three groups: D10: dexamethasone 10 mg I.V. diluted in normal saline 20cc, immediately after inter scalene block D4: dexamethasone 4 mg I.V. diluted in normal saline 20cc, immediately after inter scalene block C: control: Normal saline 20cc I.V., immediately after inter scalene block. These patient will be recruited from 3 hospitals, with two surgeons performing the surgeries. All patients will have their surgery under regional anesthesia only provided by the inter scalene plexus block, with ropivacaine 0.5% 20cc. In the postoperative period, patients will be given analgesic medication on an as needed basis. They will be instructed to take the first analgesic medication once postoperative shoulder pain has reached >3/10. They will note the time and day at which this outcome occurs.

Official Title
-----------------
Impact of Two Doses of Intravenous Dexamethasone on the Analgesic Duration of a Single-shot Interscalene Block With Ropivacaine for Shoulder Arthroscopy; a Prospective, Randomized, Placebo-controlled Study

Conditions
-----------------
Pain

Intervention / Treatment
-----------------
* Drug: Dexamethasone
* Drug: Normal Saline


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Elective shoulder arthroscopy under ropivacaine single-shot interscalene brachial plexus block anesthesia (rotator cuff repair and shoulder decompression) ASA I-III Age 18-80 years old Exclusion Criteria: Any contraindication to interscalene brachial plexus block anesthesia Interscalene brachial plexus block failure Known local anesthetics allergy Dexamethasone allergy or intolerance Any contraindication to acetaminophen Any contraindication to morphine or hydromorphone Brachial plexus neuropathies Chronic pain syndrome other than shoulder pain Routine use of opioid medication Routine use of systemic corticosteroid Pregnancy Weight below 50 kilograms Incapability to understand a numeric verbal pain scale Incapability to consent Patient refusal

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 80 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 |
| --- | --- |
| Experimental: Dexamethasone 10 mg intravenous<br>Dexamethasone 10 mg diluted with Normal Saline 17,5 mL i.v. (20 mL total) injected slowly during 30 seconds immediately after performing interscalene brachial plexus block | Drug: Dexamethasone<br>* After the performance of inter scalene plexus blockade, patients will either receive dexamethasone 10 mg i.v. (diluted with 17.5 mL normal saline), dexamethasone 4 mg i.v. (diluted with 19 mL normal saline), or normal saline 20 ml i.v.<br>* Other names: decadron;|
| Experimental: Dexamethasone 4 mg intravenous<br>Dexamethasone 4 mg diluted with Normal Saline 19 mL i.v. (20 mL total) injected slowly during 30 seconds, immediately after performing interscalene brachial plexus block | Drug: Dexamethasone<br>* After the performance of inter scalene plexus blockade, patients will either receive dexamethasone 10 mg i.v. (diluted with 17.5 mL normal saline), dexamethasone 4 mg i.v. (diluted with 19 mL normal saline), or normal saline 20 ml i.v.<br>* Other names: decadron;|
| Placebo Comparator: Normal Saline 20 mL intravenous<br>Normal saline 20 mL injected slowly during 30 seconds, immediately after performing interscalene brachial plexus block | Drug: Normal Saline<br> <br> |

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Duration of Analgesia | Defined as the time between the performance of the block and the first analgesic request | 48 hours after surgery | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Pain Scores | On a 11-points Verbal Numeric Scale 0-10 (0= no pain, 10= worst conceivable pain) | every 6 hours during the first 48 hours after surgery | 
| Residual Motor Block | Scale of 0-2 (0:inability to move fingers, 1: fingers able to move, with diminished strength compared to non operated side, 2: No motor weakness of the fingers) | 24 hours and 48 hours | 
| Sleep Disturbance | Sleep disturbance scale 0-10 (0: no sleep disturbance from pain, 10: worst conceivable sleep disruption from pain) | 24 hours and 48 hours | 
| Patients Overall Satisfaction | categorical data (1: very satisfied, would recommend this analgesia protocol to others, 0: not satisfied, would not recommend this analgesia protocol to others | 48 hours |