Peak Plasma Levels of Bupivacaine After an Erector Spinae Block (ESP)

Peak Plasma Levels of Bupivacaine After an Erector Spinae Block

The primary objective of the study is to measure plasma levels of bupivacaine following erector spinae (ESP) regional block in patients undergoing mastectomy.

Study Overview

• Status: Completed
• Conditions: Anesthesia, Local; Pharmacokinetics
• Intervention / Treatment: Other: Collection of blood samples

Detailed Description

Breast cancer is one of the most frequent types of cancer in women. Mastectomy is important in treating these cases; however, sometimes it is associated with acute and chronic pain. Multimodal analgesia, combining drug therapy and regional anesthesia, can help in preventing acute and perhaps chronic pain in breast cancer patients undergoing mastectomy.

Erector spinae block is a new regional anesthesia technique that has emerged to treat thoracic pain following thoracic and breast surgery. It consists of injecting local anesthetics in the space located between the erector and paravertebral muscles using ultrasound guidance. The injection can be done at the level of T5 allowing distribution of the drug to upper and lower dermatomes.

The dose of local anesthetic injected after erector spinae block should aim to maximize analgesia while minimizing the chance of toxic systemic concentrations. Defining the rate of absorption of local anesthetics into the blood after an erector spinae block will therefore help anesthesiologists determinate optimal analgesic doses, in terms of both safety and effectiveness.

This observational study will determine bupivacaine pharmacokinetics after single shot erector spinae block with bupivacaine, to further define the right dose and duration of surveillance in post-anesthesia care.

Methods:

For the erector spinae block, the patient will be placed in the sitting position. Using an ultrasound machine with a high frequency linear probe (Sonosite, HFL50 15-6MHz) placed in the parasagittal plane, 3cm away from the midline, the anesthesiologist will position an insulated hyperechoic needle (50-80 mm, 22 gauge, SonoPlex STIM, Nanoline, Pajun, Germany) at the level of the 5th thoracic vertebrae, between the erector spinae and the paravertebral muscles. The anesthesiologist will confirm the correct position of the needle with the injection of 1 mL of 5% dextrose. Then, after negative aspiration, he will inject bupivacaine 0.5% with epinephrine 5 mcg/mL in 5 ml aliquots for a total dose of 2mg/kg of ideal body weight (maximum of 150mg).

The end of injection will be considered as T0. Collection of 4.5mL of blood will be performed at T10min, T20min, T30min, T45min, T60min, T90min, T120min, T180min, and T240min.

Blood tubes will be immediately placed on ice to be ultimately sent to the laboratory for centrifugation and measurement of bupivacaine level using liquid chromatography-tandem mass spectrometry (LC-MS/MS) for each of the samples.

General anesthesia will then be induced in the operating room with no additional bupivacaine allowed by the anesthesiologist or the surgeon. After surgery, in the Post-Anesthesia Care Unit, the level of the sensory block will be identified by pinprick and the quality of analgesia will be evaluated using a verbal numerical rating scale, and opioid consumption will be noted.

• Study Type: Observational
• Enrollment (Actual): 18

Contacts and Locations

Study Locations

• Canada
  • Quebec
    • Montréal, Quebec, Canada, H2X 3E4
      • Centre Hospitalier de l'Universite de Montreal (CHUM)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 90 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing unilateral mastectomy under general anesthesia and erector spinae block for post-operative pain management.

Description

Inclusion Criteria:

• ASA I-III
• Undergoing unilateral mastectomy under erector spinae block and general anesthesia

Exclusion Criteria:

• Patient's refusal or inability to consent
• Allergy, hypersensibility or resistance to local anesthetic
• Contra-indication to regional anesthesia: infection in the designated area, acquired or congenital coagulopathy
• Severe hepatic or renal insufficiency (GFR<30 mL/min)

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Bupivacaine dosage in ESP block; The pharmacokinetics of bupivacaine 0.5% with epinephrine 5 mcg/mL for a total dose of 2mg/kg of ideal body weight following an ESP block will be determined by the collection of blood samples at predetermined time points.	Other: Collection of blood samples; Nine blood samples will be collected to determine bupivacaine pharmacokinetics at T10min, T20min, T30min, T45min, T60min, T90min, T120min, T180min, and T240min. T0 will be defined as the end of bupivacaine injection.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Maximal plasma concentration (Cmax) of bupivacaine after erector spinae block	The Cmax will be estimated by interpolation based on the plasmatic bupivacaine values obtained after the analysis of the blood samples.	The end of injection of bupivacaine will be considered as T0. Blood samples at T10, T20, T30, T45, T60, T90, T120, T180, and T240minutes will be collected to further analyze plasmatic bupivacaine values at these timepoints.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time (Tmax) to maximum plasma concentration Cmax of bupivacaine	The Tmax will be estimated by interpolation based on the plasmatic bupivacaine values obtained after the analysis of the blood samples.	The end of injection of bupivacaine will be considered as T0. Blood samples at T10, T20, T30, T45, T60, T90, T120, T180, and T240minutes will be performed to further analyze plasmatic bupivacaine values at these timepoints.
Sensory block level 30 minutes after arriving to Post-Anesthesia Care Unit	Sensory block level will be measured with a 6.1g von Frey filaments.	30 minutes after arriving to Post-Anesthesia Care Unit
Post-operative pain using verbal numerical rating scale	The quality of postoperative analgesia at rest will be evaluated with a verbal numeric scale (VNS) where 0 represents 'no pain' and 10 represents 'the worst pain'.	30 minutes after arriving to Post-Anesthesia Care Unit
Total opioid dose needed during Post-Anesthesia Care Unit stay (PACU)	The total dose of opioids used by the patients during the PACU stay will be recorded.	After the surgery, from the entry in the Post-Anesthesia Care Unit to the discharge from the Post-Anesthesia Care Unit, for an average of one-hour stay.

Collaborators and Investigators

• Sponsor: Centre hospitalier de l'Université de Montréal (CHUM)
• Investigators: Principal Investigator: Stephan Williams, MD, PhD, Centre Hospitalier de l'Universite de Montreal (CHUM)

Study record dates

Study Major Dates

• Study Start (Actual): June 14, 2019
• Primary Completion (Actual): October 16, 2019
• Study Completion (Actual): October 16, 2019

Study Registration Dates

• First Submitted: February 11, 2019
• First Submitted That Met QC Criteria: February 12, 2019
• First Posted (Actual): February 15, 2019

Study Record Updates

• Last Update Posted (Actual): May 31, 2022
• Last Update Submitted That Met QC Criteria: May 27, 2022
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Other Study ID Numbers: 18.308

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: Undecided

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No