NCT02755532

Bupivacaine Pharmacokinetics in Ultrasound-guided Axillary Brachial Plexus Block.

A Clinical and Pharmacokinetic Study to Evaluate the Influence of Two Bupivacaine Concentrations on Peak Plasma After Ultrasound-guided Axillary Brachial Plexus Block

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 30 (actual)
• Sponsor: Federal University of São Paulo · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

Summary

Introduction: The risk of systemic toxicity when using bupivacaine is a persistent problem, making its pharmacokinetic study crucial to the safety of regional anesthesia (RA). Little evidence exists regarding the effect of different concentrations of this drug on peak plasma levels. The present study compares two bupivacaine concentrations to establish how the concentration and exchange area affect the peak plasma level of this drug during axillary brachial plexus block. Latency and postoperative analgesia periods were also compared. Methods: 32 patients were randomly assigned to two groups. In the 0.25% group, 10 ml of 0.25% bupivacaine was injected per nerve; in the 0.5% group, 5 ml of 0.5% bupivacaine was injected per nerve. Peripheral blood samples were collected every 15 min during the first hour and every 30 min during the second hour to establish serum level dosage. High-performance liquid chromatography coupled with mass spectrometry was used for the analysis.

Conditions

• Pharmacokinetics
• Anesthetics, Local

Interventions

Type	Name	Description
DRUG	Bupivacaine 0,25%	Venous blood samples were collected prior to blocking , every 15 min during the first hour after completion of the blocking and every 30 min during the second hour after completion using an exclusive cannula. Then, 5 ml was drawn off and was stored in two EDTA tubes (BD, Franklin Lakes, NJ, USA). The EDTA tubes were centrifuged at 3,500xg for 10 min to obtain the blood plasma. This plasma was then stored in cryogenic tubes in a freezer at -80 °C until the time of the analysis. A high-performance liquid chromatography apparatus (Shimadzu, Kyoto, Japan) coupled to a Bruker mass spectrometer (MS), model Amazon (USA), with electrospray source ionization and a sequential mass spectrometry system (MS/MS) were used for the analysis. After obtaining the precursor ion, a fragment was obtained via a collision-induced dissociation process. The following molecular ions were selected: 289.0 m/z==\>140.1 m/z. The methodology was validated according to the international FDA recommendations.
DRUG	Bupivacaine 0,5%	Venous blood samples were collected prior to blocking , every 15 min during the first hour after completion of the blocking and every 30 min during the second hour after completion using an exclusive cannula. Then, 5 ml was drawn off and was stored in two EDTA tubes (BD, Franklin Lakes, NJ, USA). The EDTA tubes were centrifuged at 3,500xg for 10 min to obtain the blood plasma. This plasma was then stored in cryogenic tubes in a freezer at -80 °C until the time of the analysis. A high-performance liquid chromatography apparatus (Shimadzu, Kyoto, Japan) coupled to a Bruker mass spectrometer (MS), model Amazon (USA), with electrospray source ionization and a sequential mass spectrometry system (MS/MS) were used for the analysis. After obtaining the precursor ion, a fragment was obtained via a collision-induced dissociation process. The following molecular ions were selected: 289.0 m/z==\>140.1 m/z. The methodology was validated according to the international FDA recommendations.

Timeline

• Start date: 2014-01-01
• Primary completion: 2015-07-01
• Completion: 2015-10-01
• First posted: 2016-04-29
• Last updated: 2016-04-29