The BIS monitor screen will be covered during the procedure to ensure that anesthesia personnel involved in the care will be blinded to the BIS score and trend screen to avoid BIS score influenced changes in propofol doses. At the end of the procedure, the BIS data will be electronically transferred to a computer along with time points and other study parameters (18). Data that will be collected on case report forms include the following: date and time of BIS data collection, including start and end times; minimum, average and maximum BIS values at various time points including during propofol bolus doses, rate changes and discontinuation; average Signal Quality Index (SQI);and average electromyography (EMG).