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NCT Number: NCT07353047

The Efficacy of Personalized Local Anesthetic Dosing Based on Ultrasound-Measured Nerve Cross-Sectional Area in Brachial Plexus Block: a Non-Inferiority Randomized Controlled Trial.

This is a prospective, randomized, assessor-blinded, three-arm, non-inferiority clinical trial. The study aims to compare the effectiveness and safety of an individualized dosing strategy for local anesthetic in brachial plexus blocks against two standard methods. The experimental intervention uses ultrasound to measure the cross-sectional area (CSA) of the brachial plexus nerves to calculate a patient-specific dose of 0.5% ropivacaine. This is compared to a standard weight-based dosing regimen (2.5 mg/kg) and dosing based on the anesthesiologist's clinical experience. A total of 350 adult patients scheduled for elective unilateral upper limb surgery will be randomly assigned to one of the three groups. The primary outcome is the success rate of the nerve block 30 minutes after administration. Secondary outcomes include assessments of diaphragmatic function, postoperative pain scores, the incidence of complications (such as nerve involvement or systemic toxicity), and patient satisfaction. The hypothesis is that the CSA-based dosing method will be non-inferior to the conventional methods in achieving successful anesthesia while potentially optimizing drug dosage.

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Key information

Conditions

Upper Limb Surgery

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Age 18-80 years old, proposed for elective unilateral upper extremity surgery; ASA grade I-III; Planned to undergo ultrasound-guided interscalene sulcus brachial plexus block; Normal preoperative respiratory function; No history of neck surgery; No use of drugs that affect nerve conduction or opioids within 30 days prior to surgery

Exclusion criteria

Local infection, coagulation dysfunction, neuropathy; Allergy to ropivacaine or amide local anesthetics; Severe hepatic and renal insufficiency; Pregnancy or lactation; Expected dosing required to exceed the maximum safe single safe dose of ropivacaine; Inability to cooperate with ultrasound measurements or nerve block operators.

Treatment and study plan

CSA-based dosing of Ropivacaine

Drug

Participants assigned to this group will receive an ultrasound-guided interscalene brachial plexus block. First, the cross-sectional area (CSA) of the brachial plexus nerves at the interscalene groove will be measured in the short-axis view using ultrasound. The dose of 0.5% ropivacaine will then be calculated individually using the formula: Volume (mL) = CSA (mm²) × K, where K is a conversion coefficient (in mL/mm²) determined from a prior pilot dose-finding study. The total administered dose will not exceed the maximum recommended safe dose of ropivacaine (225 mg). The block will be performed by an experienced anesthesiologist under real-time ultrasound guidance.

Experience-based dosing of Ropivacaine

Drug

Participants assigned to this group will receive an ultrasound-guided interscalene brachial plexus block. The volume of 0.5% ropivacaine to be injected will be determined solely by the clinical judgment and experience of the attending anesthesiologist, reflecting standard real-world practice. The total administered dose will not exceed the maximum recommended safe dose of ropivacaine (225 mg). The block will be performed by an experienced anesthesiologist under real-time ultrasound guidance.

Weight-based dosing of Ropivacaine

Drug

Participants assigned to this group will receive an ultrasound-guided interscalene brachial plexus block. The dose of 0.5% ropivacaine will be calculated based on the participant's body weight using the standard formula: Dose (mg) = 2.5 mg/kg. The corresponding volume will then be administered. The total administered dose will not exceed the maximum recommended safe dose of ropivacaine (225 mg). The block will be performed by an experienced anesthesiologist under real-time ultrasound guidance.

Primary outcomes

  1. Block Success Rate

    Time frame: At 30 minutes after block completion

Study contacts

Contact information is provided by the study sponsor or research team.

Ju Gao

CONTACT

[email protected]

18051063988

Sponsors and collaborators

Lead sponsor

Northern Jiangsu People's Hospital

Other

Registry information

Important dates

Study start
2026
Primary completion
2026
Study completion
2026
First posted
Jan 20, 2026
Registry last updated
Jan 20, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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