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

This study has been completed.
Information provided by (Responsible Party):
Luiz Fernando dos Reis Falcao, Federal University of São Paulo Identifier:
First received: October 14, 2010
Last updated: May 8, 2012
Last verified: May 2012
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.

Condition Intervention Phase
Drug: bupivacaine 0.5%
Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: Double Blind (Participant, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Determination of the Minimum Effective Volume of Local Anesthetic Using Ultrasound Guidance for Interscalene Brachial Plexus Block

Resource links provided by NLM:

Further study details as provided by Federal University of São Paulo:

Primary Outcome Measures:
  • ED95 of bupivacaine minimum effective volume [ Time Frame: 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 Outcome Measures:
  • Diaphragmatic Function [ Time Frame: 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 [ Time Frame: Analgesia ]
    Post-surgery analgesia [ Time Frame: after 4 hours and 6 hours post-block ]

Estimated Enrollment: 33
Study Start Date: September 2009
Study Completion Date: June 2011
Primary Completion Date: June 2011 (Final data collection date for primary outcome measure)
Intervention Details:
    Drug: bupivacaine 0.5%
    Patients will be given bupivacaine 0.5% in different doses (up-down study).
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.


Ages Eligible for Study:   21 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts 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
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Please refer to this study by its identifier: NCT01244932

Luiz Fernando dos Reis Falcao
Sao Paulo, SP, Brazil
Sponsors and Collaborators
Federal University of São Paulo
Principal Investigator: Luiz Fernando Falcao, MD Federal University of Sao Paulo
  More Information


Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: Luiz Fernando dos Reis Falcao, Ph.D., Federal University of São Paulo Identifier: NCT01244932     History of Changes
Other Study ID Numbers: UNIFESP-01
Study First Received: October 14, 2010
Last Updated: May 8, 2012

Additional relevant MeSH terms:
Anesthetics, Local
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents processed this record on April 24, 2017