Demographic and Clinical Data: We will use and analyze patient demographic and clinical data in combination with the PK/PD data (10, 11) for Pharmacokinetic /Pharmacodynamic modeling purposes. Patient data to be collected include: age, gender, ethnicity, weight, height and body mass index. Clinical data to be collected and recorded on case report forms include: blood pressure, heart rate, temperature and end tidal carbon dioxide level (ETCO2). Other clinical data that will be recorded on case report forms include: time needed to lose consciousness (loss of verbal contact), start/stop time of propofol dosing, propofol infusion rates, propofol dose adjustments, time to eye opening on verbal command post infusion, and sedation scores (Ramsey sedation scale) post-operatively every 10 minutes (+/- 2 minutes) for the first 30 minutes and thereafter every 30 minutes (+/- 5 minutes) while in the Post Anesthesia Care Unit (PACU).