Efficacy of Pre-operative Aprepitant Plus Ondansetron vs Ondansetron Plus Placebo in Patients at Moderate-to-High Risk Post-operative Nausea (PONV) Undergoing Ambulatory Plastic Surgery

We plan to enroll women and men undergoing outpatient plastic surgical procedures under general anesthesia. Patients who are scheduled for outpatient plastic surgery will be contacted by one of the investigators, who would be involved in the care of the patient, as soon as they come to the hospital on the day of surgery. The patient will be given information regarding the study. After hospital registration and ample time to consider the study, the patient will be re-approached, and written informed consent will then be obtained. After informed consent is obtained, patients will be screened by one of the investigators for study eligibility.

Patients will be screened to evaluate if they are at high risk for PONV. Moderate-to-high risk for PONV includes having at least 2-3 of 5 risk factors. These five factors are: 1) female gender, 2) history of PONV, 3) history of motion sickness, 4) nonsmoking status, and 5) postoperative use of opioids. Women who report 3 of the 5 risk factors, and men who report 2 of the 5 risk factors, will be considered eligible for the study. As is the standard of care at Magee-Womens Hospital, all women of reproductive age are routinely screened for pregnancy and any patients who are pregnant will be informed and excluded from the study. Patients who are known in advance to be admitted (to either 23 hour observation or a formal hospital admission) will also be excluded from the study.

This is a prospective, randomized, double blind trial. Patients will be randomized by a computer generated number table to one of two groups (Group 1 - aprepitant, or Group 2 - placebo) within 3 hours before induction of anesthesia, consistent with the product package insert for aprepitant.

The standard of care in patients at moderate-to-high risk for PONV is to give prophylactic intravenous 5HT-3 antagonists (i.e. ondansetron). Therefore, all patients will receive PONV prophylaxis (ondansetron 4 mg intravenously) on induction of anesthesia.

All patients will receive a standardized general anesthetic which will include the following. Midazolam (2 mg) will be given intravenously for anxiolysis premedication. Medications used for induction of anesthesia will include; propofol (2-3 mg/ kg), rocuronium (0.6-0.8 mg/kg), and ondansetron (4 mg). Maintenance of general anesthesia will consist of sevoflurane (1.5 - 2.5%) in oxygen, fentanyl as needed for analgesia (not to exceed 10 μg/kg). Incremental doses of rocuronium will be used as necessary for muscle relaxation. Muscle relaxation will be reversed at the end of surgery with glycopyrrolate (0.01mg/kg) and neostigmine (0.05mg/kg). Criteria for reversal with neostigmine will be standardized in order to avoid the possibility of a repeat dose of the neostigmine, which in repeated doses is known to cause emesis.