The question proposed by this study, is one of patient outcomes. Does intraoperative injection of Exparel decrease postoperative use of opioid pain medications in patients undergoing thyroid and parathyroid surgery? The trial seeks to assess the effect that Exparel has on postoperative pain control.

Patients will be identified in clinic as good candidates for surgical intervention based on current standard of care. Once participants are consented, they will be randomly placed into one of three categories. The first category being patients undergoing surgery with local injection of lidocaine and epinephrine as is current practice. The second category of patients will undergo surgery with local injection of bupivacaine HCL and epinephrine preincision. The third group will undergo surgery with local injection of lidocaine and epinephrine preincision and Exparel postincision. As stated above, all patients will undergo surgery as planned, which will be standard of care, with the exception of the local anesthetic and timing of the injection. Postoperatively, patient's pain scores and opioid usage will be evaluated. Patients will be monitored by either using the patient's electronic medical record or by a pain journal that will be provided to the patients. The patients will record their pain using a scale of 1-10 with the FACES scale, as well as medication usage. Patients will return to their first postoperative appointment to further discuss their pain levels as well as medication usage. An ANOVA test will be used to determine if there is a significant difference in the amount of opioids taken postoperatively, in oral morphine equivalents, between these three groups. Opioid usage will then be compared between participants in different categories of local anesthetic to determine if there is an effect of postoperative opioid usage between different anesthetics.

Inclusion Criteria:

• Patients over the age of 18 years Patients requiring parathyroid/thyroid surgery based on the standard of care English as primary language

Exclusion Criteria:

• Patients under the age of 18 years Patients with previous history of opioid abuse Patients with a true allergy to any local anesthetic Patients with a true allergy to any opioid

There is no plan, because IPD will not be shared with other researchers.

During the consenting process, participants will be informed about the randomization aspect of the study. However, they will not be told what category/group they will be randomized into. To help with the randomization, the study team will enter the needed patient information into www.randomizer.org, which will categorize the patients into the desired groups.