Patients will receive a standard anesthetic consisting of midazolam premedication when indicated for anticipated separation anxiety, then sevoflurane inhalation utilizing nitrous oxide during mask induction, but no nitrous oxide during maintenance anesthesia. Analgesia and PONV prophylaxis is standardized as acetaminophen 15 mg/kg oral preoperative (maximum 650), followed by ketorolac 0.5 mg/kg IV (maximum 30), ondansetron 0.15 mg/kg IV, and dexamethasone 0.15 mg/kg IV. Airway maintenance will be with a laryngeal mask, and emergence conducted in the operating room with the aim of a responsive patient at time of departure from the operating room.