Did not receive funding

The goals of this study are as follows:

1. to confirm the safe dosing of ropivacaine for the erector spinae plane block
2. 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
3. assess numbness created by the erector spinae block when routine doses are administered

Inclusion Criteria:

1. Participant's age is greater than 18 years
2. Participant is undergoing a primary coronary artery bypass grafting surgery or heart valve replacement that requires a midline sternotomy incision
3. Participant's surgery is being performed by Dr. Vig Kasirajan

Exclusion Criteria:

1. Diagnosis of cirrhosis, hepatitis, primary sclerosing cholangitis
2. Abnormal liver function tests demonstrated by lab results
3. Allergy to lidocaine, ropivacaine, or midazolam
4. Morbid obesity, defined as body mass index greater than 40
5. Existing skin neuropathy on the chest or back
6. Body weight less than 50 kg
7. Participant is not able to provide verbal feedback, such as when the participant develops altered mental status or requires prolonged mechanical ventilation and sedation
8. Participant remains intubated on post-operative day 1
9. Pregnant women