General Anesthesia Emergence Induced by Methylphenidate

Based on this significant arousal stimulatory effect, the investigators hypothesize that methylphenidate (inhibitor of dopamine and norepinephrine transporters) decreases the emergence time from isoflurane general anesthesia. PRIMARY OBJECTIVE: To assess whether methylphenidate affects time of emergence from isoflurane general anesthesia. Time to emergence was defined as the time from termination of isoflurane to extubation. After stopping isoflurane infusion, when the patient breaths spontaneously with adequate tidal volume and respiratory rates, the trachea will be extubated and the time will be recorded. SECONDARY OBJECTIVES: * To assess the efficacy of methylphenidate in preventing post operative nausea and vomiting (PONV) by limited opioids consumption: PONV verbal response scale on a 0 to 10 verbally elicited scale: 0 (no nausea) to 10 (nausea as bad as it could be) * To assess the efficacy of methylphenidate in preventing opioids dose escalation (fast cognitive improvement with efficient pain control -Postoperative Pain Numeric Rating Scale: O=None; (1-3)=Mild; (4-6)= Moderate; (7-10)=Severe). Study Population: Adult patients at Ohio State University Wexner Medical Center - Sports Medicine, aged between 18-65 years, with an American Society of Anesthesiologists (ASA) physical status of I (normal healthy patient) or II (patients with mild systemic disease; no functional limitation) who are scheduled to undergo hip arthroscopic surgery - same day discharge - under isoflurane general anesthesia. Single-center, prospective, randomized, double-blind, placebo-controlled trial involving 54 subjects scheduled to undergo arthroscopic orthopedic surgery under isoflurane general anesthesia at The Ohio State University Wexner Medical Center (OSUWMC) - University Hospital East. Eligible subjects that provide voluntary and written informed consent will be included in this study.