Minimum Effective Volume of Local Anesthetic Using Ultrasound for Brachial Plexus Block

Determination of the Minimum Effective Volume of Local Anesthetic Using Ultrasound Guidance for Interscalene Brachial Plexus Block

Status

Completed

Phases

Phase 2

Study type

Interventional

Source

ClinicalTrials.gov

Registry ID

NCT01244932

Enrollment

Registered

2010-11-22

Start date

2009-09-30

Completion date

2011-06-30

Last updated

2012-05-10

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Anesthesia

Brief summary

The purpose of this study is to determine the minimum effective volume of local anesthetic for interscalene brachial plexus block using ultrasound guidance and nerve stimulator guidance.

Detailed description

This will be a single group assignment, double-blind, up-down sequential allocation study. Interscalene brachial plexus block (ISBPB) is a common nerve block given to patients who are undergoing shoulder surgery. This block has a low, but still significant, rate of complications. Reducing the volume of local anesthetic given during the block may allow some of these complications to be avoided. Participants will undergo ISBPB under ultrasound and nerve stimulator guidance. Patients will initially receive 15mL of local anesthetic (bupivacaine 0.5% with epinephrine). The volume used for each subsequent patient depends upon the success or failure of the previous patient's block - a failure will cause the volume given to increase by 1.0 mL, while a success will cause the volume to decrease by the same amount. The goal of this study is to determine the minimum effective anesthetic volume of bupivacaine 0.5% providing anesthesia in patients when using ultrasound and nerve stimulator to guide placement of the block. The secondary outcome will be the evaluation of diaphragmatic function and post-surgery analgesia.

Interventions

DRUGbupivacaine 0.5%

Patients will be given bupivacaine 0.5% in different doses (up-down study).

Study design

Allocation

RANDOMIZED

Intervention model

SINGLE_GROUP

Primary purpose

TREATMENT

Masking

TRIPLE (Subject, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender

ALL

Age

21 Years to 65 Years

Healthy volunteers

Yes

Inclusion criteria

* Patients receiving interscalene brachial plexus block for shoulder surgery * Age between 21 and 65 years * ASA physical status I/II * Body mass index \< 35 kg/m2

Exclusion criteria

* Chronic obstructive pulmonary disease * Psychiatric history * Allergy to bupivacaine * Infection in the site of block * Coagulation disorders

Design outcomes

Primary

Measure	Time frame	Description
ED95 of bupivacaine minimum effective volume	ED95	The ED95 of bupivacaine minimum effective volume determination in interscalene brachial plexus block using ultrasound guidance. \[ Time Frame: every 10 minutes until 30 minutes, after 4 hours and after 6 hours post-block \]

Secondary

Measure	Time frame	Description
Diaphragmatic Function	Diaphragmatic	Diaphragmatic Function (as assessed by diaphragmatic movement on ultrasound) \[ Time Frame: after 30 minutes, 4 hours and 6 hours post-block \]
Post-surgery analgesia	Analgesia	Post-surgery analgesia \[ Time Frame: after 4 hours and 6 hours post-block \]

Countries

Brazil

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Mar 25, 2026