Impact of Bupivacaine Dilution With Dextrose or Saline on Infraclavicular Block Outcomes

The Effect of Diluting Bupivacaine With 5% Dextrose and 0.9% NaCl on Block Success and Duration of Analgesia in Infraclavicular Block

D5W) has long been used as an intravenous fluid for hydration and energy supplementation and has recently gained increasing clinical interest in perineural injection therapies and ultrasound-guided hydrodissection. D5W has been shown to improve pain and functional outcomes in entrapment neuropathies by mechanically releasing perineural adhesions and potentially modulating neurogenic inflammation. In contrast, 0.9% sodium chloride (normal saline) is routinely used as a dilution medium for local anesthetics in peripheral nerve blocks; however, emerging evidence suggests that alternative diluents such as D5W may influence block onset and efficacy.

The infraclavicular block is a commonly used ultrasound-guided technique for brachial plexus anesthesia, providing reliable anesthesia and postoperative analgesia for upper extremity surgery. This study aims to compare the effects of diluting bupivacaine with either D5W or 0.9% NaCl on block success and duration of analgesia in patients undergoing infraclavicular block. Secondary outcomes include block onset characteristics, sensory and motor block profiles, and perioperative analgesic requirements. The findings may help determine whether D5W represents a safe and effective alternative diluent to saline in routine regional anesthesia practice.

Study Overview

• Status: Recruiting
• Conditions: Postoperative Analgesia; Infraclavicular Brachial Plexus Block; Bupivacaine; Dextrose; Block Success
• Intervention / Treatment: Diagnostic test: Blocked and analgesia time

Detailed Description

D5W) has traditionally been used as an intravenous fluid to provide hydration and caloric support. In recent years, D5W has gained increasing attention for its use in innovative perineural injection therapies and ultrasound-guided hydrodissection techniques, particularly in the management of peripheral nerve entrapment syndromes. Clinical and randomized controlled studies have demonstrated that perineural D5W hydrodissection can mechanically separate fibrotic tissues surrounding compressed nerves, improve perineural blood flow, reduce pain, and enhance sensory and functional recovery in conditions such as carpal tunnel syndrome and meralgia paresthetica. Beyond its mechanical effects, D5W is also thought to modulate neurogenic inflammation, regulate nociceptive C-fiber activity through local glucose-related mechanisms, and potentially promote neuroregenerative processes.

In routine regional anesthesia practice, 0.9% sodium chloride (normal saline) is the most commonly used diluent for local anesthetics to achieve the desired volume and concentration for peripheral nerve blocks. However, experimental and clinical data suggest that the sodium content and physicochemical properties of saline may influence the onset and quality of neural blockade. Some studies have reported earlier sensory block onset when local anesthetics are diluted with D5W rather than saline, suggesting that the choice of diluent may affect block characteristics.

The infraclavicular brachial plexus block is a well-established ultrasound-guided technique that provides reliable anesthesia and postoperative analgesia for surgeries involving the mid and distal upper extremity. Visualization of neural structures allows optimized local anesthetic spread and consistent block performance in routine clinical practice.

This study is designed to evaluate the effect of diluting bupivacaine with either D5W or 0.9% NaCl on block success and duration of analgesia in patients undergoing ultrasound-guided infraclavicular block. Secondary outcomes will include onset time of sensory and motor block, block quality, postoperative analgesic consumption, and safety parameters. By investigating an alternative dilution strategy, this study aims to contribute to optimizing peripheral nerve block techniques and improving patient-centered clinical outcomes.

• Study Type: Interventional
• Enrollment (Estimated): 90
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Burçin Alaçam; Phone Number: +905465903851; Email: burcin.ersoy90@gmail.com

Study Locations

• Turkey (Türkiye)
  • Sakarya, Turkey (Türkiye), 54100
    • Recruiting
    • Sakarya University-Anesthesiology and Reanimation Department
    • Contact: Burçin Alaçam; Phone Number: +905465903851; Email: burcin.ersoy90@gmail.com

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Patients who agree to participate in the study and provide written informed consent
• Patients scheduled for elective upper extremity surgery for whom infraclavicular block is considered appropriate for anesthetic management
• Age between 18 and 65 years
• American Society of Anesthesiologists (ASA) physical status I-III
• Patients with a normal neurological examination in the extremity scheduled for peripheral nerve block

Exclusion Criteria:

• Patients who decline to participate in the study or refuse to provide informed consent
• History of allergy or hypersensitivity to study medications
• Body mass index (BMI) ≥ 30 kg/m²
• Body weight less than 40 kg
• Age below 18 years or above 65 years
• History of significant cardiac disease (e.g., arrhythmia, conduction disorders)
• Presence of coagulopathy (international normalized ratio [INR] > 1.5 and/or platelet count < 100,000/mm³)
• Hepatic failure or significant liver dysfunction
• Pregnant patients
• Infection at the planned peripheral block site
• Presence of neurological deficit in the extremity planned for peripheral nerve block
• Patients with uncontrolled diabetes mellitus and/or established diabetic neuropathy
• American Society of Anesthesiologists (ASA) physical status IV

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group D; Participants in this group will receive an ultrasound-guided infraclavicular brachial plexus block using bupivacaine diluted in a 1:1 ratio with 5% dextrose in water (D5W) to achieve a predetermined total injection volume (e.g., total volume of 30 mL). The block will be performed under standardized aseptic conditions by an experienced anesthesiologist. Block success, sensory and motor block characteristics, duration of analgesia, and postoperative analgesic requirements will be assessed and recorded.	Diagnostic test: Blocked and analgesia time; All eligible participants will be informed in detail about the study objectives, procedures, potential risks, and benefits by the responsible investigator, and all questions will be answered prior to enrollment. Written informed consent will be obtained from each participant before any study-related procedures are initiated. Following the ultrasound-guided infraclavicular block, sensory block assessment will be performed using a sterile single-use needle for a pinprick test. Light punctate stimuli will be applied to dermatomal areas corresponding to the branches of the brachial plexus on the blocked extremity. Participants will be asked to compare the sensation with the contralateral limb and to report the perceived sensation as "normal," "reduced," or "absent." Sensory block assessments will be performed at 5, 10, 15, 20, and 30 minutes after block administration. Sensory block onset time will be defined as the time point at which the participant reports absence of pinprick sensation
Experimental: Group S; Participants in this group will receive an ultrasound-guided infraclavicular brachial plexus block using bupivacaine diluted in a 1:1 ratio with 0.9% sodium chloride (normal saline) to achieve a predetermined total injection volume (e.g., total volume of 30 mL). The block will be performed under standardized aseptic conditions by an experienced anesthesiologist. Block success, sensory and motor block characteristics, duration of analgesia, and postoperative analgesic requirements will be assessed and recorded.	Diagnostic test: Blocked and analgesia time; All eligible participants will be informed in detail about the study objectives, procedures, potential risks, and benefits by the responsible investigator, and all questions will be answered prior to enrollment. Written informed consent will be obtained from each participant before any study-related procedures are initiated. Following the ultrasound-guided infraclavicular block, sensory block assessment will be performed using a sterile single-use needle for a pinprick test. Light punctate stimuli will be applied to dermatomal areas corresponding to the branches of the brachial plexus on the blocked extremity. Participants will be asked to compare the sensation with the contralateral limb and to report the perceived sensation as "normal," "reduced," or "absent." Sensory block assessments will be performed at 5, 10, 15, 20, and 30 minutes after block administration. Sensory block onset time will be defined as the time point at which the participant reports absence of pinprick sensation

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Sensory block onset time	Sensory block onset time will be defined as the time from completion of the ultrasound-guided infraclavicular block until the participant reports complete loss of pinprick sensation in the dermatomal areas corresponding to the branches of the brachial plexus, assessed using a sterile pinprick test.	Assessed at 5, 10, 15, 20, and 30 minutes after block administration.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Motor block duration	Motor block duration will be defined as the time from onset of motor block (Modified Upper Extremity Bromage Scale ≥1) until full recovery to Bromage score 0.	From block performance until complete motor recovery (up to 24 hours postoperatively).
Intraoperative need for additional anesthetic or analgesic intervention	Requirement for supplemental anesthetic or analgesic interventions during surgery will be recorded as a binary outcome (yes/no) and as total additional drug consumption if applicable.	During the intraoperative period.
Postoperative analgesic efficacy	Postoperative pain intensity will be assessed using the Visual Analog Scale (VAS; 0 = no pain, 10 = worst imaginable pain) at postoperative 2, 6, 12, and 24 hours.	Postoperative 2, 6, 12, and 24 hours.

Collaborators and Investigators

• Sponsor: Burçin Alaçam, MD

Study record dates

Study Major Dates

• Study Start (Actual): March 9, 2026
• Primary Completion (Estimated): May 15, 2026
• Study Completion (Estimated): July 15, 2026

Study Registration Dates

• First Submitted: January 28, 2026
• First Submitted That Met QC Criteria: February 3, 2026
• First Posted (Actual): February 4, 2026

Study Record Updates

• Last Update Posted (Actual): March 11, 2026
• Last Update Submitted That Met QC Criteria: March 9, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Digestive System and Oral Physiological Phenomena; Dentistry; Dental Physiological Phenomena; Dental Occlusion
• Other Study ID Numbers: SAU-ANE-BA-03

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