Dexamethasone Versus Dexmedetomidine as Adjuvants for Nerve Blocks

Study Overview
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Brief Summary
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When used as perineural (PN) adjuvants to local anesthetics (LAs), dexamethasone (DX) and dexmedetomidine (DXD) have been well documented to prolong the duration of peripheral nerve blocks. These drugs have important differences in terms of cost and safety profiles. This randomized controlled trial (RCT) will compare PN DX and PN DXD for ultrasound-guided infraclavicular brachial plexus blocks (ICBs). Since analgesic and sensory duration can be influenced by factors different to block, motor block duration is the main outcome. The protocol is designed as an equivalency trial and hypothesize that both drugs result in similar durations. The equivalency margin is set at 3 hrs.

Official Title
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A Randomized Comparison Between Perineural Dexamethasone and Perineural Dexmedetomidine as Adjuvants for Ultrasound-Guided Infraclavicular Blocks

Conditions
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Pain, Postoperative, Pain, Acute, Upper Extremity Injury

Intervention / Treatment
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* Drug: Dexamethasone
* Drug: Dexmedetomidine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: age between 18 and 75 years American Society of Anesthesiologists classification 1-3 body mass index between 20 and 35 Exclusion Criteria: adults who are unable to give their own consent pre-existing neuropathy (assessed by history and physical examination) coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or prothrombin time ≥ 50) renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. creatinine ≥ 100) hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work up i.e. transaminases ≥ 100) allergy to local anesthetics (LAs) pregnancy prior surgery in the infraclavicular region chronic pain syndromes requiring opioid intake at home

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 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
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Perineural dexamethasone<br>addition of dexamethasone to local anesthetics in infraclavicular brachial plexus block | Drug: Dexamethasone<br>* Dexamethasone as perineural local anesthetic adjuvant<br>|
| Active Comparator: Perineural dexmedetomidine<br>addition of dexmedetomidine to local anesthetics in infraclavicular brachial plexus block | Drug: Dexmedetomidine<br>* Dexmedetomidine as perineural local anesthetic adjuvant<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Motor block duration | Elapsed time since the end of LA injection until return of hand and fingers movement | 24 hours after block | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensory block duration | Elapsed time since the end of LA injection until return of hand and fingers sensation | 24 hours after block | 
| Analgesic block duration | Elapsed time since the end of LA injection until first sensation of pain in surgical area | 24 hours after block | 
| Block performance time | Elapsed time from skin desinfection until the end of LA injection | 1 hour before surgery | 
| Intensity of pain during block procedure | Evaluated with a numeric rating score from 0 to 10 | 1 hour before surgery | 
| Block onset time | Time required to reach a minimal sensorimotor composite score of 14 points out of a maximum of 16 points | 1 hour before surgery | 
| Sensory and motor block score | Sensorimotor block assessed every 5 minutes until 30 minutes using a 16-point composite score evaluating sensory and motor block of musculocutaneus, medium, radial and ulnar nerves. Sensation will be assessed with ice in each nerve territory with a 0 to 2 point scale. 0= no block, patients can feel cold; 1= analgesic block, patient can feel touch but not cold; 2= anesthetic block, patient cannot feel cold or touch. Motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis. Succesfull blocks at 30 minutes correlate with a final score ( sum of all individual sensory and motor scores) of at least 14 points out of 16. | 30 minutes post injection | 
| Incidence of complete block | Percentage of blocks with a minimal sensorimotor composite score of 14 points out of a maximum of 16 points at 30 minutes post injection | 30 minutes post injection | 
| Perioperative glycemic levels | Capillary dextrose measurements at pre block, 1 hour post-surgery and 6 hours post-surgery | Perioperative period | 
| Perioperative median artery pressure (MAP) | Average of MAP and HR registered during preblock, intraoperative and up to 2 hours of postoperative period | 2 hours after surgery | 
| Perioperative heart rate (HR) | Average MAP registered during preblock, intraoperative and up to 2 hours of postoperative period | 2 hours after surgery | 
| Postoperative persistent sedation | Persistent sedation after surgery using Ramsay sedation scale. 1= anxious agitated or restless; 2= co-operative, oriented and tranquil; 3= responds to command only; 4= brisk response to light pain or loud auditory stimulus; 5= sluggish response to light pain or loud auditory stimulus; 6= no response. | 2 hours after surgery | 
| Respiratory depression | Low respiratory rate (lower than 8 breaths per minute) or persistent oxygen requirement (pulse oximetry lower than 90% without supplementary oxygen) | 2 hours after surgery | 
| Incidence of block side effects | Presence of paresthesia, local anesthetic systemic toxicity, vascular puncture, pneumothorax, hemidiaphragmatic paralysis, Horner syndrome or hoarseness | 2 hours after surgery | 
| Persistent neurologic deficit | Presence of persistent sensory or motor postoperative deficit | 7 days post surgery | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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nerve block adjuvants, dexamethasone, dexmedetomidine, nerve block duration