Pharmacokinetic Profile and Dermatomal Coverage of the Erector Spinae Plane Block

Study Overview
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Brief Summary
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The goals of this study are as follows: to confirm the safe dosing of ropivacaine for the erector spinae plane block develop a pharmacokinetic profile of the erector spinae plane block, which will help demonstrate how quickly and how closely toxic levels are reached when a routine dose of ropivacaine is given for this nerve block assess numbness created by the erector spinae block when routine doses are administered

Official Title
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Pharmacokinetic Profile and Dermatomal Coverage of the Erector Spinae Plane Block: a Comparison of Bolus Dosing and Continuous Infusion

Conditions
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Pain, Postoperative, Pain, Chest

Intervention / Treatment
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* Drug: Ropivacaine 0.25%-NaCl 0.9% Injectable Solution
* Drug: Ropivacaine 0.2%-NaCl 0.9% Injectable Solution


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Participant's age is greater than 18 years Participant is undergoing a primary coronary artery bypass grafting surgery or heart valve replacement that requires a midline sternotomy incision Participant's surgery is being performed by Dr. Vig Kasirajan Exclusion Criteria: Diagnosis of cirrhosis, hepatitis, primary sclerosing cholangitis Abnormal liver function tests demonstrated by lab results Allergy to lidocaine, ropivacaine, or midazolam Morbid obesity, defined as body mass index greater than 40 Existing skin neuropathy on the chest or back Body weight less than 50 kg Participant is not able to provide verbal feedback, such as when the participant develops altered mental status or requires prolonged mechanical ventilation and sedation Participant remains intubated on post-operative day 1 Pregnant women

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Supportive Care
Allocation: Non-Randomized
Intervention Model: Sequential Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: single<br>local anesthetic is delivered as a single bolus | Drug: Ropivacaine 0.25%-NaCl 0.9% Injectable Solution<br>* 0.25% ropivacaine administered through a nerve catheter<br>|
| Active Comparator: continuous<br>local anesthetic is delivered as a continuous infusion | Drug: Ropivacaine 0.2%-NaCl 0.9% Injectable Solution<br>* 0.2% ropivacaine administered through a nerve catheter<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Cmax | The maximum concentration of serum ropivacaine after pre-determined dose is delivered through the ESP nerve catheter | 28 hours | 
| Tmax | The time elapsed from initial ropivacaine administration to Cmax | 28 hours | 
| Area of analgesia | The area of numbness experienced in the chest wall; measured using a pinprick test and documented on a cartoon map showing a chest wall and dermatomal borders | 4 hours | 
| Duration of analgesia | The duration of numbness to the chest wall; start time will be when the local anesthetic bolus is given, and end time will be when the participant reports the resolution of chest wall numbness | 4 hours |