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

Phase 2
Completed
Conditions
Anesthesia
Registration Number
NCT01244932
Lead Sponsor
Federal University of São Paulo
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.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
33
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

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Primary Outcome Measures
NameTimeMethod
ED95 of bupivacaine minimum effective volumeED95

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 Outcome Measures
NameTimeMethod
Diaphragmatic FunctionDiaphragmatic

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

Post-surgery analgesiaAnalgesia

Post-surgery analgesia \[ Time Frame: after 4 hours and 6 hours post-block \]

Trial Locations

Locations (1)

Luiz Fernando dos Reis Falcao

🇧🇷

Sao Paulo, SP, Brazil

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