Effect of Dexamethasone on Plasma Levels of Bupivacaine and Dexamethasone After a Single-injection Interscalene Nerve Block.

August 9, 2026 updated by: Pontificia Universidad Catolica de Chile

Effect of Dexamethasone on Plasma Levels of Bupivacaine and Dexamethasone Following a Single-injection Interscalene Nerve Block: A Randomized Controlled Study

Recent studies have highlighted the comparative advantages of perineural dexamethasone, particularly regarding its safety profile and its ability to prolong analgesia in various peripheral nerve blocks. A recent systematic review demonstrated that perineural administration of dexamethasone significantly extends the duration of analgesia compared to intravenous administration.

The mechanism of action of perineural dexamethasone remains unclear. Moreover, there is a lack of research comparing the systemic absorption of local anesthetics administered perineurally with or without dexamethasone, and the systemic absorption and bioavailability of dexamethasone when used as a perineural adjuvant have not been studied.

Objective: This study aims to compare plasma concentrations of bupivacaine following a single-shot interscalene block with dexamethasone administered either perineurally or intravenously.

Methodology: A prospective, randomized, double-blind trial will be conducted involving 40 patients undergoing shoulder surgery requiring a single-shot interscalene block. Each patient will receive 20 mL of 0.25% bupivacaine combined with 8 mg of dexamethasone administered either perineurally or intravenously. Venous blood samples (5 mL) will be collected at 5, 10, 20, 40, 80, 120, and 240 minutes post-block, and one sample at discharge, to measure plasma concentrations of both enantiomers of bupivacaine (D(+)-bupivacaine and L(-)-bupivacaine) and dexamethasone.

Outcomes: The study will compare plasma levels of bupivacaine between groups, characterize the pharmacokinetics of bupivacaine and dexamethasone, and assess block duration and opioid consumption.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

40

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

  • Name: Ricardo Fuentes, MD
  • Phone Number: 56955043270
  • Email: rsfuente@uc.cl

Study Locations

  • Chile
      • Santiago, Chile
        • Recruiting
        • Red Salud UCChristus
        • Contact:
          • Victor Contreras, MSN
          • Phone Number: 56981895232
          • Email: vecontre@uc.cl

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

- ASA I-II patients, with a body mass index (BMI) between 20 and 34 kg/m2 scheduled for shoulder surgery requiring single-needle interscalene block

Exclusion Criteria:

- Chronic opioid use, liver failure, kidney failure, allergy to protocol drugs

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Intravenous dexamethasone
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Drug: administration of dexamethasone intravenously
IV dexamethasone administration will be added to the interscalene block. In the control group, dexamethasone will be applied perineurally.
No Intervention: Local dexamethasone
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What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
plasma levels of bupivacaine between groups
Time Frame: 4 hours
Plasma levels of bupivacaine after a single-shot interscalene block combined with dexamethasone administration ev or perineurally
4 hours

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Pontificia Universidad Catolica de Chile

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

May 19, 2026

Primary Completion (Estimated)

December 1, 2026

Study Completion (Estimated)

December 1, 2027

Study Registration Dates

First Submitted

December 5, 2025

First Submitted That Met QC Criteria

December 30, 2025

First Posted (Actual)

January 7, 2026

Study Record Updates

Last Update Posted (Actual)

August 12, 2026

Last Update Submitted That Met QC Criteria

August 9, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 250429018

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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