Pharmacokinetic Profile and Dermatomal Coverage of the Erector Spinae Plane Block

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