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.

• Rescue antiemetics [Time frame: From date of admission to perioperative procedural area until hospital discharge or up to 30 days whichever is first]
• Incidence of vomiting [Time frame: Upon post-anesthesia care unit (PACU) arrival (within ~2-3 hours after procedure), upon PACU discharge (~4-5 hours after procedure/medically cleared to leave PACU), admission to ASU directly after medically cleared from PACU to discharge from ASU]
• patients with no PONV [Time frame: arrival at hospital to post op day 7]
• Compare the incidence of PONV in PACU and ASU [Time frame: Upon post-anesthesia care unit (PACU) arrival (within ~2-3 hours after procedure), upon PACU discharge (~4-5 hours after procedure/medically cleared to leave PACU), admission to ASU directly after medically cleared from PACU to discharge from ASU]
• Clinically important PONV [Time frame: Upon post-anesthesia care unit (PACU) arrival (within ~2-3 hours after procedure), upon PACU discharge (~4-5 hours after procedure/medically cleared to leave PACU), admission to ASU directly after medically cleared from PACU to discharge from ASU]
• Readmission rates [Time frame: Discharge of hospital to 7 days post operatively]
• Postoperative Delirium Measured by 4AT Assessment [Time frame: Preoperative baseline and upon PACU discharge (~4 hours after procedure/medically cleared to leave PACU).]
• Compare APFEL Score [Time frame: Preoperatively in Holding area]
• Compare length of stays between groups [Time frame: From date of procedure through hospital discharge (up to 30 days after procedure date, whichever comes first)]
• opioid consumption [Time frame: From date of procedure through hospital discharge (up to 30 days after procedure date, whichever comes first)]
• Patient Satisfaction [Time frame: post operative day 1 and 5]
• Adverse Events [Time frame: These events will be assessed after immediate administration in the preoperative holding area and within 4 hours postoperatively]