Does Perineural Dexamethasone Prolong Duration of a Nerve Block?

Study Overview
=================
Brief Summary
-----------------
The purpose of this study is to investigate whether dexamethasone as an adjuvant to ropivacaine for adductor canal block increases duration of the sensory block, when controlling for a systemic effect using a paired design and bilateral blocks. The investigators hypothesize that adding dexamethasone to ropivacaine will prolong block duration compared with ropivacaine + placebo.

Official Title
-----------------
Does Perineural Dexamethasone Prolong Duration of an Adductor Canal Block When Controlling for a Systemic Effect? A Paired, Randomized, Blinded, Study in Healthy Volunteers

Conditions
-----------------
Healthy Volunteers

Intervention / Treatment
-----------------
* Drug: Ropivacaine + dexamethasone
* Drug: Ropivacaine + placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: American Society of Anesthesiologists class 1 Body Mass Index 18-30 Exclusion Criteria: Allergy to study medication Earlier trauma or surgery to lower limb Diabetes Mellitus Alcohol or drug abuse Daily intake of opioids or steroids last 4 weeks Daily intake of any analgesics last 48 hours

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 30 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

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

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Ropivacaine + dexamethasone<br>20 ml ropivacaine 0.5% + 0.5 ml dexamethasone 4 mg7ml | Drug: Ropivacaine + dexamethasone<br>* Adductor canal block, single bolus<br>|
| Placebo Comparator: Ropivacaine + placebo<br>20 ml ropivacaine 0.5% + 0.5 ml isotonic saline ad | Drug: Ropivacaine + placebo<br>* Adductor canal block, single bolus<br>|

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

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference in duration of sensory block between dexamethasone and placebo assessed as cold sensation with an alcohol swab | Duration is defined as time from block performance until recovery of cold sensation to an alcohol swab, assessed every hour post-block (and every half hour when pain scores during the tonic heat stimulation test is above 0, except at 2 and 3 hours post block where there will be a break and no assessments will be performed. | 0-36 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Difference between dexamethasone and placebo in the duration of a sensory block assessed by pin-prick | Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour post block (except at 2 and 3 hours post block where there will be a break and no assessments will be performed). | 0-36 hours | 
| Difference between dexamethasone and placebo in the duration of a sensory block assessed as maximum pain during a tonic heat stimulation test | Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour post block (except at 2 and 3 hours post block where there will be a break and no assessments will be performed). Recovery of normal sensation is defined as VAS pain scores ± 10 mm of the pre-block value. | 0-36 hours | 
| Difference between dexamethasone and placebo in the duration of a sensory block assessed as warmth detection threshold | Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour post block (except at 2 and 3 hours post block where there will be a break and no assessments will be performed and only assessed if pain scores during tonic heat stimulation is above 0 ). Recovery of normal sensation is defined as detection thresholds of ± 2 degrees C of the pre-block value. | 0-36 hours | 
| Difference between dexamethasone and placebo in the duration of a sensory block assessed as heat pain detection threshold | Duration is defined as time from block performance until recovery of normal sensation, assessed on the hour post block (except at 2 and 3 hours post block where there will be a break and no assessments will be performed and only assessed if pain scores during tonic heat stimulation is above 0 ). Recovery of normal sensation is defined as detection thresholds of ± 2 degrees C of the pre-block value. | 0-36 hours | 
| Difference in maximum pain scores between dexamethasone and placebo during block and after recovery of normal sensation | Pain scores during a tonic heat stimulation will be compared at 4 h post block and 1 h after pain scores have returned to the pre-block values. | 0-36 hours | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
US-guided peripheral nerve block, Anesthetics, Local, duration, Sensation, adductor canal block, lower limb, Adjuvants, Anesthesia