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.
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: CSA-based dosing of Ropivacaine, Experience-based dosing of Ropivacaine, Weight-based dosing of Ropivacaine.
- Who it may be relevant to
- Registry conditions: Upper Limb Surgery. Basic parameters: 18 years — 80 years · All.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- China
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
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.
Interventions
- Drug CSA-based dosing of Ropivacaine
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 w - Drug Experience-based dosing of Ropivacaine
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. - Drug Weight-based dosing of Ropivacaine
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 outcome measures
- Block Success Rate [Time frame: At 30 minutes after block completion]
Eligibility criteria
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.
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: No
Study design
- Allocation
- Randomized
- Model
- Parallel assignment
- Masking
- Double blind
- Primary purpose
- Other
Study locations
China · 1 center
- Jianjun Qian — Yangzhou
Identifiers
NCT: NCT07353047 · 2025ky401