Minimum Effective Volume of 0.375% Bupivacaine in Interscalene Brachial Plexus Block

Minimum Effective Volume of 0.375% Bupivacaine in Ultrasound- and Nerve Stimulator-guided Interscalene Brachial Plexus Block for Shoulder Surgery

The use of ultrasound in regional anesthesia enables reduction in the local anesthetic volume. The present study aimed to determine the minimum effective volume of 0.375% bupivacaine with epinephrine for interscalene brachial plexus block for shoulder surgery. Following approval by the Research Ethics Committee, patients with a physical condition of I or II according to the American Society of Anesthesiologists, between 21 and 65 years old and subjected to elective surgery of the shoulder and interscalene brachial plexus block will be recruited. The volume of the anesthetic will be determined using a step-up/step-down method and based on the outcome of the preceding block. Positive or negative block results in a 1mL reduction or increase in volume, respectively. The success of the block is defined as the presence of motor block in two muscle groups and the absence of thermal and pain sensations in the necessary dermatomes within 30 minutes of the injection. Diaphragmatic paralysis, pulmonary function and analgesia will be quantified at 30 minutes, 4 and 6 hours. Data will undergo statistical analysis in order to determine minimum effective volume of 0.375% bupivacaine and, secondarily, the maximum volume that maintains the diaphragmatic function, evaluate diaphragm paralysis and its influence in pulmonary function.

Study Overview

• Status: Unknown
• Conditions: Shoulder Surgery
• Intervention / Treatment: Drug: Bupivacaine 0,375%

• Study Type: Interventional
• Enrollment (Anticipated): 33
• Phase: Phase 2

Contacts and Locations

Study Locations

• Brazil
  • Sao Paulo, Brazil, 04024-002
    • Recruiting
    • Federal University of São Paulo
    • Contact: Luiz Fernando Saldanha de Almeida, MD; Email: luizfsa@gmail.com
    • Contact: Marcelo Vaz Perez, MD PhD; Email: marcelovazperez@gmail.com
    • Sub-Investigator: Marcelo V Perez, MD PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Age between 21 and 65 years
• Candidates for an elective surgical intervention on the shoulder with indication for anesthesia via brachial plexus block
• Physical condition of I or II according to the American Society of Anesthesiologists
• Body mass index up to 35 kg.m-2

Exclusion Criteria:

• Chronic obstructive pulmonary disease
• Cognitive impairment or active psychiatric condition
• Infection at the site of the puncture for the block
• Coagulopathy
• Bupivacaine allergy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: Triple

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Bupivacaine; Bupivacaine 0,375%	Drug: Bupivacaine 0,375%; Positive or negative block results in a 1-mL reduction or increase in volume, respectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Minimum effective volume of 0,375% bupivacaine	Minimum effective volume of 0,375% bupivacaine with epinephrine in ultrasound-guided interscalene brachial plexus block for shoulder surgery	30 minutes

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximum 0,375% bupivacaine volume that maintains the diaphragmatic function	Maximum effective volume of 0,375% bupivacaine with epinephrine in ultrasound-guided interscalene brachial plexus block for shoulder surgery without diaphragmatic block	Before block, 10, 20 and 30 minutes, 4 and 6 hours after
Pulmonary function	Spirometric evaluation of forced vital capacity	Before block, 30 minutes, 4 and 6 hours after
Diaphragmatic Function	Diaphragmatic movement on ultrasound	Before block, 30 minutes, 4 and 6 hours after

Collaborators and Investigators

• Sponsor: Federal University of São Paulo

Study record dates

Study Major Dates

• Study Start: August 1, 2012
• Primary Completion (Anticipated): January 1, 2013
• Study Completion (Anticipated): September 1, 2013

Study Registration Dates

• First Submitted: August 13, 2012
• First Submitted That Met QC Criteria: August 16, 2012
• First Posted (Estimate): August 17, 2012

Study Record Updates

• Last Update Posted (Estimate): August 17, 2012
• Last Update Submitted That Met QC Criteria: August 16, 2012
• Last Verified: August 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Central Nervous System Depressants; Peripheral Nervous System Agents; Sensory System Agents; Anesthetics; Anesthetics, Local; Bupivacaine
• Other Study ID Numbers: Bupivacaine 0,375%