A Randomized Comparison Between 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg of Perineural Dexmedetomidine for Ultrasound-Guided Infraclavicular Block

January 4, 2026 updated by: Julián Aliste, McGill University Health Centre/Research Institute of the McGill University Health Centre
This study will compare three different doses of perineural dexmedetomidine 0.67 mcg/kg, 1 mcg/kg, and 1.33 mcg/kg as adjuvants to local anesthetics for ultrasound-guided infraclavicular brachial plexus blocks (ICBs). Our research hypothesis is that 1.33 mcg/kg will provide a 15%-longer duration than 1mcg/kg, which in turn will provide a 15%-longer duration than 0.67 mcg/kg. Since analgesic duration and sensory duration can be influenced by intake of pain medications and surgical trauma to small cutaneous nerves, respectively, we will select motor block duration as the main outcome to better target the action of dexmedetomidine on the brachial plexus.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

With the approval of Ethics Committee of the McGill University Health Centre, a total of 69 patients undergoing upper extremity surgery (elbow and below) will be recruited. Recruitment will be carried out by an investigator not involved in patient care one day before surgery

All ICBs will be supervised by the coauthors and conducted preoperatively in an induction room.

After skin disinfection and draping, the ICB will be performed with a previously described technique. In each group, a proven 90% effective volume of 35 mL of local anesthetic solution will be injected. As LA solution, it will be used a mixture of lidocaine 1.0%-bupivacaine 0.25% with epinephrine 5 µ/mL plus PN 2 mg dexamethasone. The injectate will be slowly injected through the block needle.

Patients will be randomized to receive the study drug, PN dexmedetomidine 0.67 mcg/kg or PN dexmedetomidine 1 mcg/kg, or PN dexmedetomidine 1.33 mcg/kg mixed with the above-mentioned LA solution.

A research assistant (licensed anesthesiologist) will prepare the local anesthetic solutions and will add the study drug following the randomization order. The operator, patient, and investigator assessing the block will be blinded to group allocation.

The primary outcome will be the duration of the motor block (defined as the temporal interval between the end of LA injection through the block needle and the return of movement to the hand and fingers) for patients with successful ICBs. Patients will be provided with a data sheet and asked to record the time at which motor function returns. An investigator blinded to group allocation will collect this data sheet in person (inpatients) or by phone (outpatients) on postoperative day 1.

Study Type

Interventional

Enrollment (Estimated)

69

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Canada
    • Quebec
      • Montreal, Quebec, Canada, H3G 1A4
        • Recruiting
        • McGill University Health Centre
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • patients undergoing upper limb surgery at or below the elbow
  • age between 18 and 75 years
  • American Society of Anesthesiologists classification 1-3
  • body mass index between 18 and 35 kg/m2

Exclusion Criteria:

  • adults who are unable to give their own consent
  • allergy or contraindication to dexmedetomidine
  • exposure to dexmedetomidine during the previous 48 hrs
  • pre-existing neuropathy (assessed by history and physical examination)
  • coagulopathy (assessed by history and physical examination and, if deemed clinically necessary, by blood workup i.e. platelets ≤ 100, International Normalized Ratio ≥ 1.4 or partial prothrombin time ≥ 50)
  • renal failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work-up i.e. creatinine. eGFR < 90)
  • hepatic failure (assessed by history and physical examination and, if deemed clinically necessary, by blood work-up i.e. transaminases ≥ 100)
  • allergy to LA
  • pregnancy (as institutional policy, female patients with childbearing potential undergoing non urgent surgery are tested preoperatively for pregnancy with blood tests)
  • breast feeding
  • prior surgery in the infraclavicular region
  • chronic pain syndromes requiring opioid intake at home

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Quadruple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: 0.67 mcg/kg
Addition of dexmedetomidine 0.67 mcg/kg to local anesthetics in infraclavicular brachial plexus block
Drug: dexmedetomidine (perineural) 0.67 mcg/kg
Perineural dexmedetomidine 0.67 mcg/kg will be added to the local anesthetic used to block the cords of the brachial plexus with an infraclavicular approach.
Experimental: 1 mcg/kg
Addition of dexmedetomidine 1 mcg/kg to local anesthetics in infraclavicular brachial plexus block
Drug: dexmedetomidine (perineural) 1 mcg/kg
Perineural dexmedetomidine 1 mcg/kg will be added to the local anesthetic used to block the cords of the brachial plexus with an infraclavicular approach.
Experimental: 1.33 mcg/kg
Addition of dexmedetomidine 1.33 mcg/kg to local anesthetics in infraclavicular brachial plexus block
Drug: dexmedetomidine (perineural) 1.33 mcg/kg
Perineural dexmedetomidine 1.33 mcg/kg will be added to the local anesthetic used to block the cords of the brachial plexus with an infraclavicular approach.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Motor block duration
Time Frame: 24-48 hours after block
The elapsed period in minutes between the ending time of the local anesthetic injection and the time of return of hand and fingers movement
24-48 hours after block

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Block performance time
Time Frame: 1 hour before surgery
Sum of: 1- the acquisition time of the ultrasonographic image. and 2- the time to perform the block itself (from the skin anesthesia to the end of local anesthetic injection)
1 hour before surgery
Intensity of pain during block procedure
Time Frame: 1 hour before surgery
Evaluated with the Numeric Rating Scale for Pain. This scale is graduated from 0 to 10 points. A 0-point score represents the absence of pain, and a 10-points score represents the worst imaginable pain. Patients will be asked to rate their pain verbally with this scale. The blinded assessor will register the score reported.
1 hour before surgery
Block onset time
Time Frame: 1 hour before surgery
Time required to reach a minimal sensorimotor composite score of 14 points out of a maximum of 16 points. The sensorimotor score is described in outcome 7.
1 hour before surgery
Sensory and motor block score
Time Frame: 30 minutes after the ending time of local anesthetic injection

The sensorimotor block will be assessed every 5 minutes until 30 minutes after the end of local anesthetic injection using a 16-point composite score evaluating sensory and motor block of musculocutaneous, 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, the patient can feel touch but not cold; 2= anesthetic block, the patient cannot feel cold or touch.

The motor function will be assessed for each nerve with a 0 to 2 points scale where 0= no motor block; 1= paresis; 2= paralysis.

Successful 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 after the ending time of local anesthetic injection
Incidence of complete block
Time Frame: 30 minutes after the ending time of local anesthetic injection
Percentage of blocks with a minimal sensorimotor composite score of 14 points out of a maximum of 16 points at 30 minutes after the injection
30 minutes after the ending time of local anesthetic injection
Incidence of surgical anesthesia
Time Frame: 30-60 minutes after the ending time of local anesthetic injection
Ability to proceed with surgery without the need for intravenous narcotics, general anesthesia, rescue blocks or local anesthesia infiltration by the surgeon
30-60 minutes after the ending time of local anesthetic injection
Respiratory depression
Time Frame: 30 minutes after the nerve block to 2 hours after surgery

Presence of low respiratory rates (lower than 8 breaths per minute) or persistent oxygen requirements (pulse oximetry lower than 90% without supplementary oxygen).

The respiratory rate and pulse oximetry are continuously measured intra- and post-operatively (in the post-anesthetic care unit) as a standard of care with a multiparameter monitor. Alarms are set to alert when predetermined levels are reached
30 minutes after the nerve block to 2 hours after surgery
Bradycardia
Time Frame: 30 minutes after the nerve block to 2 hours after surgery
Defined as a heart rate lower than 50 beats per minute. The heart rate is continuously measured intra- and post-operatively (in the post-anesthetic care unit) as a standard of care with a multiparameter monitor. Alarms are set to alert when predetermined levels are reached
30 minutes after the nerve block to 2 hours after surgery
Hypotension
Time Frame: 30 minutes after the nerve block to 2 hours after surgery
Mean arterial pressure lower than 60 mmHg. The blood pressure is measured intra- and post-operatively (in the post-anesthetic care unit) as a standard of care with a multiparameter monitor. Alarms are set to alert when predetermined levels are reached
30 minutes after the nerve block to 2 hours after surgery
Postoperative persistent sedation
Time Frame: 2 hours after surgery

Persistent sedation after surgery using Ramsay sedation scale. The scale has 6 points from 1 to 6. A higher score represents a more sedated patient.

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
Persistent neurologic deficit
Time Frame: 7 days after surgery
Presence of persistent sensory or motor postoperative deficit. The patients will be contacted by telephone and inquired about any sensory or motor deficit in the operated extremity.
7 days after surgery
Sensory block duration
Time Frame: 24-48 hours after block
The elapsed period in minutes between the ending time of the local anesthetic injection and the time of the return of hand and fingers sensation
24-48 hours after block
Analgesic block duration
Time Frame: 24-48 hours after block
The elapsed period in minutes between the ending time of the local anesthetic injection and the time of the first sensation of pain in the surgical area
24-48 hours after block
Incidence of nerve block side effects
Time Frame: 0 minutes after skin disinfection to 30 minutes after the nerve block
Determined by the presence of paresthesia, local anesthetic systemic toxicity, vascular puncture, Horner syndrome, hoarseness, or pneumothorax after the block.
0 minutes after skin disinfection to 30 minutes after the nerve block

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

McGill University Health Centre/Research Institute of the McGill University Health Centre

Investigators

  • Principal Investigator: Julián Aliste, MD, McGill University Health Centre/Research Institute of the McGill University Health Centre

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 28, 2025

Primary Completion (Estimated)

June 30, 2026

Study Completion (Estimated)

June 30, 2026

Study Registration Dates

First Submitted

November 18, 2025

First Submitted That Met QC Criteria

November 18, 2025

First Posted (Estimated)

November 25, 2025

Study Record Updates

Last Update Posted (Actual)

January 7, 2026

Last Update Submitted That Met QC Criteria

January 4, 2026

Last Verified

January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2025-11084

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Clinical Trials on Analgesia

Clinical Trials on dexmedetomidine (perineural) 0.67 mcg/kg

Search Similar Trials

Sponsors and Collaborators

Medical Conditions

Drug Interventions

CROs by country

CROs in Jordan

Conditions

Rare Diseases

Drug Interventions

Dietary Supplements

Sponsor/Collaborators

Locations

Subscribe