Ultrasound-Guided Infraclvicular Block Using Dexmedetomidine Versus Nalbuphine as Adjuvants to Bupivacaine in Upper Limb Orthopedic Surgery

Ultrasound-Guided Infraclvicular Block Using Dexmedetomidine Versus Nalbuphine as Adjuvants to Bupivacaine in Upper Limb Orthopedic Surgery: A Prospective, Randomized, Double-Blind Controlled Study

this study is designed to evaluate and compare the efficacy of dexmedetomidine and nalbuphine as adjuvants to 0.5% bupivacaine in ultrasound-guided infraclavicular brachial plexus block for patients undergoing elective upper limb orthopedic surgeries on the duration of analgesia.

Study Overview

• Status: Not yet recruiting
• Conditions: Regional Anaesthesia
• Intervention / Treatment: Drug: Nalbuphine; Drug: Dexmedetomidine

Detailed Description

Regional anesthesia is an integral component of modern anesthetic practice. It provides high-quality surgical anesthesia and superior postoperative analgesia while avoiding airway manipulation, minimizing systemic opioid use, and facilitating early ambulation and discharge .

Compared with general anesthesia, regional techniques reduce postoperative pain scores, nausea, and opioid requirements, leading to faster recovery and higher patient satisfaction. They are especially valuable in orthopedic upper-limb surgeries where prolonged postoperative analgesia is desired.

For upper limb procedures, various brachial plexus approaches-interscalene, supraclavicular, infraclavicular, and axillary-are utilized depending on the surgical site. Ultrasound guidance has greatly improved the safety and success rates of these blocks by allowing direct visualization of the nerves, needle, and spread of local anesthetic (LA).

The infraclavicular approach targets the cords of the brachial plexus surrounding the axillary artery in the infraclavicular fossa. It provides dense anesthesia and analgesia for surgeries of the elbow, forearm, and hand. Advantages over the supraclavicular or axillary approaches include reliable blockade of the musculocutaneous, median, ulnar, and radial nerves with a single injection, Lower risk of pneumothorax or phrenic nerve palsy and better catheter stability for continuous analgesia .

Despite these benefits, the main limitation is the finite duration of analgesia when using local anesthetics alone. Adjuvants have been explored to extend block duration and enhance quality without increasing toxicity. Commonly used agents include opioids, clonidine, dexmedetomidine, magnesium sulfate, dexamethasone, and others.

Dexmedetomidine is a highly selective α₂-adrenergic receptor agonist with sedative, anxiolytic, and analgesic properties and minimal respiratory depression.

It acts centrally through activation of α₂ receptors in the locus coeruleus inhibits norepinephrine release, producing sedation (Brummett et al., 2009) , and has peripheral action through hyperpolarization of C and Aδ nerve fibers via inhibition of sodium and potassium channels prolongs the effect of local anesthetics.

The addition of Dexmedetomidine as adjuvant to local bupivacaine in regional anesthesia has proven to : Shortens onset time of sensory and motor block, Prolongs block duration and postoperative analgesia by 3-6 hours, Reduces rescue analgesic consumption, and Provides mild sedation without respiratory depression.

However, potential adverse effects include bradycardia and hypotension related to systemic absorption, particularly at higher doses.

Nalbuphine hydrochloride is a synthetic opioid agonist-antagonist that acts predominantly as a κ-receptor agonist and µ-receptor antagonist. This pharmacologic profile provides potent analgesia with limited risk of respiratory depression, pruritus, or nausea commonly associated with pure µ-agonists such as morphine or fentanyl.

When used as an adjuvant to local anesthetics, nalbuphine is thought to: Prolong sensory and motor block duration, increase postoperative analgesia, Reduce opioid consumption, and has Minimal side effects . it produce its effects through acting on opioid receptors located on peripheral sensory nerve endings and by reducing inflammatory mediator release.

• Study Type: Interventional
• Enrollment (Estimated): 66
• Phase: Phase 1

Contacts and Locations

• Study Contact: Name: Momen mostafa meki, Dr; Phone Number: 088 01223344886; Email: moamen.meki@med.aun.edu.eg
• Study Contact Backup: Name: Hossam El-din Gamal Fakhry, Dr.; Phone Number: 088 01026269773; Email: hossam.hg@aun.edu.eg

Study Locations

• Egypt
  • Asyut Governorate
    • Asyut, Asyut Governorate, Egypt
      • Faculty of medicine Assiut University, Assiut,
      • Contact: Momen mostafa meki, Dr; Phone Number: 088 01223344886; Email: moamen.meki@med.aun.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

Adults aged 18-65 years ASA I-II (American Society of Anesthesiologists physical status classification) Scheduled for elective upper limb orthopedic surgeries Able to provide informed consent to participate in the study

Exclusion Criteria:

Refusal to participate in the study Pregnancy Allergy to any study drug(s) Neurological disease (e.g., neuropathies, central nervous system disorders) Coagulopathy or active bleeding disorders Severe systemic diseases (e.g., uncontrolled cardiovascular, renal, or liver disease) Opioid abuse or history of substance use disorder

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: nalbuphine group; • Patients in group N (Nalbuphine group) will receive 29 mL of 0.5% bupivacaine + 1 mL (containing 10 mg nalbuphine)	Drug: Nalbuphine; Nalbuphine will be added to .5% bupivacaine as an adjuvant in infraclavicular nerve block
Active Comparator: Dexmedetomidine group; • Patients in group D (Dexmedetomidine group) will receive 29 mL of 0.5% bupivacaine + 1mL (containing 75 µg dexmedetomidine	Drug: Dexmedetomidine; Dexmedetomidine will be added to .5% bupivacaine as an adjuvant in infraclavicular nerve block; Other Names: precedex

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Our primary outcome of this study will be: Duration of Analgesia.	Definition: The time interval (in minutes) between the completion of the infraclavicular block injection and the first request for rescue analgesia (VAS ≥ 3). Scale: Visual Analog Scale (VAS) Scale Title: Visual Analog Scale for Pain (VAS) Minimum Value: 0 (no pain) Maximum Value: 10 (worst possible pain) Interpretation: Higher VAS scores indicate worse pain, and a score of ≥ 3 indicates the need for rescue analgesia.	till 24 hour postoperative

Secondary Outcome Measures

Outcome Measure	Time Frame
Onset time of sensory and motor block	till 20 minute after the block
Duration of sensory and motor block	20 minute after the block
Time to first rescue analgesic request	till 24 hour postoperative
Heart rate (HR)	till 24 hour postoperative
Mean arterial blood pressure (MAP)	24 hour postoperative

Collaborators and Investigators

• Sponsor: Assiut University
• Investigators: Principal Investigator: Momen mostafa meki, Dr, Assiut University

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): April 1, 2027

Study Registration Dates

• First Submitted: November 27, 2025
• First Submitted That Met QC Criteria: December 10, 2025
• First Posted (Actual): December 12, 2025

Study Record Updates

• Last Update Posted (Actual): December 12, 2025
• Last Update Submitted That Met QC Criteria: December 10, 2025
• Last Verified: November 1, 2025

More Information

Terms related to this study

• Keywords: Dexmedetomidine; Bupivacaine; Infraclavicular block; Nalbuphine; Duration of analgesia
• Additional Relevant MeSH Terms: Heterocyclic Compounds, 1-Ring; Heterocyclic Compounds; Heterocyclic Compounds, Fused-Ring; Azoles; Alkaloids; Polycyclic Aromatic Hydrocarbons; Polycyclic Compounds; Imidazoles; Heterocyclic Compounds, 4 or More Rings; Morphinans; Opiate Alkaloids; Heterocyclic Compounds, Bridged-Ring; Phenanthrenes; Dexmedetomidine; Nalbuphine
• Other Study ID Numbers: Infraclavicular nerve block

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES

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.: No