Aprepitant to Improve Same Day Discharge for TKA

This is a prospective, randomized, double-blind, placebo-controlled trial involving adults undergoing primary total knee arthroplasties at Endeavor Health SKH with presumed same-day discharge (as identified by the orthopedic surgery team prior to surgery). Patients will be randomly assigned to either receive 32 mg of intravenous (IV) preoperative aprepitant, in addition to the standard antiemetic protocol (4 mg IV dexamethasone after induction of MAC sedation anesthesia and 4 mg IV ondansetron at surgical closure), or the standard protocol with placebo (saline solution in same volume at the time aprepitant is given in the preoperative holding area by nursing). Aprepitant will be administered by the preoperative nurse in the holding area to ensure blinding of the anesthesia, surgical, and postoperative teams. All patients will receive either epidural or spinal anesthesia following our standard regional anesthesia protocol, with or without an adductor canal block. Intraoperatively, all patients will receive propofol infusions titrated to a RASS of 0 to -2 per the standard of care protocol at SKH. All patients will receive postoperative rescue antiemetics as needed and within the PACU admission order set choices for PONV.