poor recruitment

The purpose of this study is to study the effect of two standard of care sedative medications on sleep stages and total sleep time. The investigators hypothesize that the α2 agonist, dexmedetomidine, will improve sleep quality by increasing N2 and N3 sleep as well as total sleep time when compared to GABA agonists.

This is a single center randomized pilot study comparing the effects of an α2 agonist (dexmedetomidine) versus GABA agonists (propofol or a benzodiazepine) on total sleep time and sleep quality. For the purposes of enrollment and analysis all benzodiazepines used for sedation (mainly midazolam and lorazepam) will be considered equivalent. Patients who are mechanically ventilated and sedated will be enrolled. The initial sedative will be determined by the managing medical team and the medication will be active at the time of enrollment. The patients will then be randomized to either continue their current sedative or be switched to either propofol or dexmedetomidine. PSG data will be collected for up to 96 hours, beginning at enrollment for all patients. The analysis of PSG will not begin until after a 8 hour "washout" period has completed to minimize carryover effect of prior sedatives.

Inclusion Criteria:

• Adult patients admitted to the medical intensive care unit who require mechanical ventilation and are sedated with a GABA agonist with the expectation of being mechanically ventilated for greater than 24 hours.

Exclusion Criteria:

• Subjects who are less than 18 years
• Subjects who are pregnant (a pregnancy test will be performed on all women of child bearing age)
• Inability to obtain informed consent from the patient or his/her surrogate
• Subjects who are physiologically benzodiazepine dependent, and at risk of withdrawal syndromes
• Subjects with anoxic brain injuries, strokes, or neurotrauma
• Medical team following patient unwilling to change sedation regimen
• Subjects who are moribund and not expected to survive 24 hours or actively withdrawing medical support
• Documented allergy to study medications
• Subjects with advanced heart block at time of screening
• Prisoners
• RASS target of less than or equal to -4 at the time of screening
• PSG equipment unavailable