Dose-Finding Study: MEV90 for Local Anesthetic in Interscalene Block for Supraclavicular Nerves Block

NCT07338916 | Recruiting

• 2 other identifiers: Project Nº34, 2025251213001
• Study Type: interventional
• Target: 55
• Locations: 1 country
• Sites: 1

Brief Summary

This study aims to determine the minimum effective volume (MEV90) of local anesthetic required to achieve sensory block of the supraclavicular nerves when performing a single-shot ultrasound-guided interscalene brachial plexus block (ISB). These nerves provide sensation to the skin over the clavicle and shoulder and are often involved in surgeries such as shoulder arthroscopy and clavicle repair.

Conditions

Brachial Plexus Blockade; Shoulder Surgery; Superficial Cervical Plexus Block

Keywords

Interscalene Block; Brachial Plexus Blockade; Supraclavicular nerves block; Shoulder Surgery; Miminum Effective Volume 90; MEV90

Outcome Measures

Primary Outcomes (1)

• Minimum Effective Volume (MEV90) for Supraclavicular Nerve Block via Interscalene Approach

  The primary outcome is the calculation of the minimum effective volume of local anesthetic (MEV90) required to achieve complete sensory block of the supraclavicular nerves following a single-shot ultrasound-guided interscalene brachial plexus block. Success is defined as absence of cold and touch sensation at the midpoint of the clavicle, assessed using an ice test.

  30 minutes after completion of the block

Secondary Outcomes (7)

• Sensorimotor Block Score for Interscalene Block

  Every 5 minutes up to 30 minutes after block completion.

• Onset Time of Sensorimotor Block

  Up to 30 minutes after block completion.

• Sensory Block at Shoulder Arthroscopy Portals

  30 minutes after block completion.

• Sensory Block of Auricular, Occipital, and Transverse Cervical Nerves

  30 minutes after block completion.

• Pain Score During Block Procedure

  Immediately after block completion.

Study Arms (1)

Minimum Effective Volume 90 (MEV90)

EXPERIMENTAL

Participants in this arm will receive a single-shot ultrasound-guided interscalene brachial plexus block as part of standard perioperative analgesia for shoulder arthroscopy. The intervention consists of injecting bupivacaine 0.5% with epinephrine (5 µg/mL) between the anterior and middle scalene muscles at the level of the C5-C6 nerve roots, using an in-plane technique under real-time ultrasound guidance.

Drug: Ultrasound-Guided Interscalene Block with Bupivacaine

Interventions

Ultrasound-Guided Interscalene Block with Bupivacaine DRUG

Participants will receive a single-shot interscalene brachial plexus block performed under real-time ultrasound guidance. The block targets the C5-C6 nerve roots between the anterior and middle scalene muscles using an in-plane technique. The local anesthetic is bupivacaine 0.5% with epinephrine (5 µg/mL). The injected volume ranges from 12 mL to 30 mL, determined by a dose-finding algorithm (biased coin up-and-down sequential design) to calculate the minimum effective volume (MEV90) for supraclavicular nerve block. All procedures are performed by experienced anesthesiologists following standard safety protocols, including incremental injection with aspiration and continuous monitoring (ECG, SpO₂, non-invasive blood pressure).

Minimum Effective Volume 90 (MEV90)

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age ≥ 18 years
• ASA physical status I to III
• Body Mass Index (BMI) between 18 and 35 kg/m²
• Weight ≥ 50 kg
• Scheduled for shoulder arthroscopy requiring an interscalene brachial plexus block for analgesia
• Able to provide informed consent

You may not qualify if:

• Inability to provide informed consent
• Coagulopathy (platelet count ≤100,000; INR ≥1.4)
• Significant pulmonary disease (restrictive or obstructive)
• Renal insufficiency (creatinine ≥1.2 mg/dL)
• Hepatic insufficiency (transaminases ≥100 U/L)
• Allergy to local anesthetics
• Pregnancy
• Pre-existing neuropathy
• Previous surgery in ipsilateral cervical or supraclavicular region
• Contralateral hemidiaphragmatic paralysis or vocal cord paralysis

Sponsors & Collaborators

• Hospital del Trabajador de Santiago: lead

Study Sites (1)

Hospital del Trabajador

Providencia, Chile

RECRUITING

MeSH Terms

Interventions

Bupivacaine

Intervention Hierarchy (Ancestors)

Anilides; Amides; Organic Chemicals; Aniline Compounds; Amines

Central Study Contacts

Germán Aguilera, MD

CONTACT

+56985205514; german.aguilera@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NA
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: SINGLE GROUP
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: January 4, 2026
• First Posted: January 14, 2026
• Study Start: April 1, 2026
• Primary Completion (Estimated): November 1, 2026
• Study Completion (Estimated): December 1, 2026
• Last Updated: April 8, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

CL (1)