IV Dexamethasone for Prolongation of Peripheral Nerve Block

Study Overview
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Brief Summary
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This is a volunteer study examining the effect of different doses of IV dexamethasone on prolongation of median nerve block in the forearm.

Detailed Description
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18 healthy volunteers aged 18-50 will be recruited (6 patients in each dosing group). Each volunteer will receive two forearm median nerve blocks separated by a two week washout period. One block will be conducted alongside an infusion of normal saline (control). The other block will be conducted alongside a randomised dose of IV dexamethasone (2, 4 or 8mg). The order of these interventions will be random. Blocks will be assessed quantitatively with cold and sharp sensation, electrical stimulation, quantitative sensory testing (thermal tolerance) and grip strength dynamometry. Measures or sensory and motor block including onset, intensity and duration will be compared between dosing groups.

Official Title
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A Volunteer Study to Determine the Optimal Dose of IV Dexamethasone Required for Prolongation of Peripheral Nerve Block

Conditions
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Anesthesia, Conduction

Intervention / Treatment
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* Drug: IV dexamethasone


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: ASA 1 (normal healthy) volunteers. 18 - 50 years of age. 60 - 100kg weight. English speaking. Female volunteers of childbearing potential will be required to provide a negative pregnancy test before being allowed to participate. Females of child bearing potential must be willing to use medically acceptable birth control methods between study interventions and for a minimum of 2 weeks following the second nerve block. Exclusion Criteria: Medical disorders (including bleeding disorders). Use of systemic steroids within 2 weeks of the study, prescription medications, live viral vaccines or any recreational drug use. Hypersensitivity to bupivacaine, dexamethasone or any component of saline. Contraindication to regional anesthetic block. Inability to provide informed consent. Baseline abnormality of hand sensation or motor function. Pregnancy / breast feeding. Individuals with mental health disorders (for example bipolar disorder or depression). Individuals with cataracts or glaucoma. Any known contraindication to IV dexamethasone as per the product monograph - bacteremia and systemic fungal infections, hypersensitivity to any of the products components, gastric and duodenal ulcers, certain viral infections i.e. varicella herpes genitalis.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

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
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dexamethasone 2mg<br>The experimental intervention in this arm will be an IV infusion of 2mg of dexamethasone. Volunteers will also have a cross-over placebo comparator (saline infusion). | Drug: IV dexamethasone<br>* An infusion of IV dexamethasone<br>* Other names: Dexamethasone sodium phosphate injection USP;|
| Experimental: Dexamethasone 4mg<br>The experimental intervention in this arm will be an IV infusion of 4mg of dexamethasone. Volunteers will also have a cross-over placebo comparator (saline infusion). | Drug: IV dexamethasone<br>* An infusion of IV dexamethasone<br>* Other names: Dexamethasone sodium phosphate injection USP;|
| Experimental: Dexamethasone 8mg<br>The experimental intervention in this arm will be an IV infusion of 8mg of dexamethasone. Volunteers will also have a cross-over placebo comparator (saline infusion). | Drug: IV dexamethasone<br>* An infusion of IV dexamethasone<br>* Other names: Dexamethasone sodium phosphate injection USP;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The duration of sensory anesthesia and analgesia following median nerve block |  | This will be assessed for up to 12 hours following block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The duration of motor block following median nerve block |  | This will be assessed for up to 12 hours following block | 
| Side effects related to nerve block or IV infusion of dexamethasone |  | Volunteers will be phoned at 24-36 hrs and then 7-10 days to ensure full resolution of the block | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Regional anesthesia, Adjuvant, Dexamethasone