Minimizing ICU Neurological Dysfunction With Dexmedetomidine-induced Sleep (MINDDS II)

Inclusion Criteria:

• Aged 60 years or older

• Scheduled to undergo a cardiac surgical procedure with cardiopulmonary bypass

• Planned postoperative admission to the intensive care unit (ICU)

Exclusion Criteria:

• Allergy or hypersensitivity to dexmedetomidine or the placebo study medication

• Preexisting diagnosis of Alzheimer's Disease or Related Dementia, severe cognitiveimpairment or delirium at baseline

• Severe liver failure (Child-Pugh score > 5)

• History of obstructive sleep apnea

• Severe deficit(s) due to structural or anoxic brain damage

• Undergoing a surgical procedure requiring total circulatory arrest

• SARS-CoV-2 positive or symptomatic (e.g., fever, cough, loss of taste/smell)

• Blind, deaf, or unable to communicate in English

• Patients experiencing circumstances for which long-term follow-up might be difficult (e.g., homelessness, active psychotic disorder, or substance abuse)

• Co-enrollment in other interventional studies that, in the opinion of the siteinvestigator and/or PI, might interfere with study participation, collection, orinterpretation of the study data