Patients frequently experience problems with sleep while admitted to the ICU. Good sleep is important in ensuring that your immune system responds properly to infection, for your heart to function optimally, and to support normal brain function such as memory.

To address sleep problems in the ICU, a bundle of interventions to support more normal sleep are provided. These bundles consist of medications such as sedatives and environmental changes such as less frequent times being assessed overnight and noise reduction strategies. Although medications can make patients appear to be sleeping, most medications do not provide patients with restful sleep. More research is needed on medications that better mimick restful sleep. One such medication is dexmedetomidine. When formally measured dexmedetomidine can make sleep appear more like a patient sleeping at home as compared to the hospital.

The purpose of this study is to test whether giving a patient in the intensive care unit dexmedetomidine helps have a more restful sleep and possibly be more alert and/or interactive the next day.

To see if dexmedetomidine improves sleep, the investigators will compare the quality of sleep of two different groups of participants: one group that receives dexmedetomidine at night for 2 nights in a row and another group that does not. How well one sleeps will be measured, in either group, will be assessed by a portable sleep machine that is attached by several stickers.

This study is called a pilot or feasibility study. A pilot study assesses how easy it is to recruit patients, whether the sleep machine is tolerated, and amount of time sleep is measured.

It is anticipated that about 50 people will take part in this study. This study should take approximately 2 years to complete, and the results should be known in about 1-2 years thereafter.

Inclusion Criteria:

• Adult patient aged 18 years old or over admitted to the ICU
• Anticipated to stay in the ICU for another 48 hours after the first sleep recording
• Mechanically ventilated or on high flow oxygen (Optiflow)
• Hemodynamically stable
• Conscious, non-sedated patient with capacity to complete a self-reported sleep assessment*

Exclusion Criteria:

• Contraindication to dexmedetomidine (including but not limited to allergy and bradycardia [heart rate < 50 beats per minute])
• Currently receiving dexmedetomidine or other alpha-2 agonists (e.g., clonidine)
• Patients with structural neurological disease (e.g., stroke or tumor or traumatic brain injury) or degenerative neurologic disease (e.g., Parkinson's disease or dementia) and GCS < 14
• Patients with second- or third-degree heart block (unless pacemaker implanted)
• Patients with clinically significant hepatic or renal disease
• Patients with limitations in therapy or actively being palliated
• Patients with primary psychiatric disorder (e.g., new diagnosis of or uncontrolled schizophrenia, severe depression)
• Patients experiencing substance intoxication or withdrawal (e.g., severely agitated delirium)
• Patients participating in other studies involving the use of pharmacologically active substances
• Treating clinician believes study participation is not in the patient's best interest
• Pregnancy or breastfeeding