The purpose of this study is 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.

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.

Inclusion Criteria:

• Male or female, 18 to 65 years of age
• ASA I or II
• Capable and willing to consent
• Participants literate in English language

Exclusion Criteria:

• ADHD with current use of methylphenidate
• Hypersensitivity to methylphenidate
• ASA III, IV or V
• Patients with severe visual or auditory disorder
• Illiteracy
• Presence of a clinically diagnosed anxiety, agitation, major psychiatric condition such as bipolar disorder, uncontrolled major depression, schizophrenia
• Tics or Tourette's syndrome
• Glaucoma
• Hypertension, history of atrial arrhythmias (atrial fibrillation, atrial flutter), myocardial infarction
• Taking or have taken within the past 14 days a monoamine oxidase inhibitor or MAOI (Selegiline)
• Subjects who have participated or are currently participating in a clinical trial of an investigational drug within 30 days prior to surgery
• Any condition, which in the opinion of the investigator would make subject ineligible for participation in the study such as history of unstable cardiovascular, pulmonary, renal, hepatic, neurologic (seizures), hematologic or endocrine abnormality (hyperthyroidism, unstable Diabetes type I/II)

34 days

Continued multi-modal monitoring and vigilance with regard to any suspected adverse effects, including cardiovascular effects will help to fill the informational gap with regards to unknown cardiovascular side effects, emergence delirium incidence and perioperatory awareness.Due to the potential risk of drug related serious side effects, any clinical evidence of a serious adverse event will place the study on clinical hold until a full assessment and decision is made by the responsible parties.