"Providing Good Sleep for ICU Sedation"

Normal saline infusion

"Infusion of Dexmedetomidine will be administrated during the overnight sleep study. An initial target concentration of 0.25 ng/ml will be selected. After 5 min, the sedative point will be assessed and the concentration will be adjusted stepwise by increments and decrements of 0.05 ng/ml. This process will be repeated until the target sedative state is achieved. Using the Richmond Agitation Sedation Scale (RASS) infusion rates, using known pharmacokinetic parameters will be adjusted to achieve equivalent levels of sedation (RASS -3) for both DEX and propofol sessions.~We aim to achieve an RASS of -3 so that the subjects are moderately sedated. This state of sedation will be maintained for 3-4 hours."

"For propofol, an initial concentration of 0.75 ng/ml will be targeted. Depending on the score achieved, the infusion rate will be increased or decreased every 5 min by 0.2 ng/ml until the target sedative state is achieved.~Note that the target sedative state (RASS score of -3) is the same for both DEX and propofol sessions, with the investigator being unaware of which drug is being administered. To ensure the investigator is not aware of the type of drug being administered, all drug delivery systems will be covered.~Intravenous drug delivery will be continued throughout the scanning period for 3-4 hours to maintain equivalent levels of sedation for both DEX and propofol."