Specific Aims

1. Establish the feasibility of larger trial by implementing a sleep protocol in the ICU at 2 different sites. Specifically will be estimating the recruitment rates of patients and the compliance with both interventions.
2. Measure the safety and tolerance of adding night-time sedation with dexmedetomidine using adverse effects and withdrawal rates as indicators.
3. Measure the effect of nocturnal dexmedetomidine on pertinent clinical outcomes and use this outcome data to plan a larger, multicenter trial in this area.

The goal of this study is to determine whether a night-time protocol that incorporates a pharmacologic intervention associated with improved sleep (i.e. dexmedetomidine) will improve sleep quality and reduce the incidence of delirium and sub-syndromal delirium in critically ill patients.

The goal of this study is to determine whether a nocturnal protocol that incorporates a pharmacologic intervention associated with improved sleep (i.e. dexmedetomidine) will improve sleep quality and reduce the incidence of delirium and sub-syndromal delirium in critically ill patients where ventilator settings have been optimized to optimize sleep quality.

1. To evaluate the impact of a dexmedetomidine-focussed nocturnal sleep protocol that minimizes arousal from sleep on:

   1. incidence of delirium [Intensive Care Delirium Screening Checklist (ICDSC) score ≥ 4]
   2. incidence of sub-syndromal delirium (ICDSC score 1-3)
   3. outcomes specifically defined by place of discharge from hospital (i.e., home,rehabilitation, or long-term care)

2. To gain an understanding of the effect of night-time sedation with dexmedetomidine on:

   1. patient safety
   2. self-reported sleep quality
   3. sleep quality and architecture [based on a subgroup of 10 patients at Tufts Medical Center who will be evaluated using polysomnography(PSG) for one night]
   4. time spent within targeted sedation goal
   5. time spent without pain
   6. agitation-related events
   7. length of stay in the ICU
   8. duration of mechanical ventilation
   9. length of hospital stay
   10. total health care costs by measuring medication costs and hospitalization costs, as well as calculating effectiveness (sleep, sedation and pain management vs. cost).

This multicenter study will be performed at:

1. Hopital Maissonneuve Rosemont, Montreal, PQ
2. Tufts Medical Center, Boston, MA

Inclusion Criteria:

1. Age ≥ 18 years
2. Current expectation on the part of the patient's admitting intensivist for patients to require ICU care for >/= 48 hrs
3. Administered at least one sedative dose (scheduled or prn).

Exclusion Criteria:

1. Patients with delirium (intensive care delirium screening checklist score ≥ 4) or disorientation (not oriented to person and/or place)
2. Patients in whom an ICDSC cannot be reliably completed (e.g. primary language is not French or English, baseline severe hearing impairment)
3. Inability by one of the investigators to obtain informed consent from the legally authorized representative
4. Treating physician refusal
5. Heart rate ≤ 50 BPM
6. Systolic blood pressure ≤ 90 mmHg despite the administration of norepinephrine ≥ 15 mcg/min and/or vasopressin ≥ 0.04 units/min
7. Admission with acute decompensated heart failure
8. History of heart block without pacemaker based on hospital admission note.
9. Acute alcohol withdrawal based on hospital admission note
10. History of end stage liver failure (based on presence of ≥ 1 or more of the following: AST/ALT ≥ 2 times ULN, INR ≥ 2, total bilirubin ≥ 1.5)
11. Irreversible brain disease consistent with severe dementia based on hospital admission note
12. Pregnancy (all women of child-bearing age will undergo a pregnancy test prior to study enrolment)
13. Known allergy or sensitivity to clonidine or dexmedetomidine
14. Current treatment with dexmedetomidine

p. Prognosis considered to be hopeless based on consultation with the ICU admitting physician q. Age ≥80 years r. Currently being managed with a high frequency oscillating mode (HFOV) of mechanical ventilation.

Blinding for participants, care providers, investigator and outcomes assessor