The goal of this clinical trial is to learn whether a superficial cervical plexus block improves quality of recovery after thyroid surgery. Investigators will compare a superficial cervical plexus block with bupivacaine compared to an identical procedure performed saline placebo to see if there is a difference in quality of recovery on the first postoperative day. The main question to answer is: • Does a superficial cervical plexus block with bupivacaine compared to placebo improve quality of recovery in patients having thyroid surgery. Participants will: * Fill out an initial preoperative survey * Be randomized to receive a superficial cervical plexus block with bupivacaine or saline placebo while under anesthesia before the surgery starts * Fill out a survey about recovery on the first day after surgery