The purpose of this chart review study is to determine whether the use of dexmedetomidine, a selective α2-adrenergic receptor agonist with sedative, analgesic, and antinociceptive properties, would be associated with a lower incidence of delirium when compared to propofol and midazolam. We hypothesize that sedation with dexmedetomidine following cardiac surgery with CPB will be associated with a lower incidence of postoperative delirium.

Delirium is the most common psychiatric syndrome found in the general hospital setting. Between 32 - 80% of cardiac surgery patients may experience post-operative delirium. Because failure to recognize delirium leads to increased morbidity and mortality and prolonged hospital stays, there are compelling clinical and financial reasons to improve the identification and treatment of delirium. Dexmedetomidine, a selective alpha2-adrenergic receptor agonist, may be an alternative to current postoperative sedation when it comes to lowering the incidence of delirium.

Comparisons: The use of postoperative (at sternal closure) dexmedetomidine will be compared to current standards of care propofol and midazolam for postoperative sedation.

Inclusion Criteria:

1. Diagnosis of a coronary artery disease, cardiac valve disease, or vascular problems requiring elective surgical intervention
2. Age older than 18 years of age, less than 90 years of age
3. Fluency in English, and willingness to participate in the study
4. No history of recent (< 3 months) of alcohol or drug abuse
5. No pre-operative evidence of heart block
6. No history of dementia, schizophrenia, or post-traumatic stress disorder

Exclusion Criteria:

1. A preexisting diagnoses of dementia, schizophrenia, active or recent alcohol or drug abuse/dependence; post-traumatic stress disorder; acute intoxication (i.e., positive urine drug and/or alcohol test at the time of initial evaluation or upon hospitalization for surgery)
2. Age younger than 18, or older than 89 years of age
3. Inability to understand enough English to complete required diagnostic testing
4. Unwillingness to participate in the study
5. Inability of subject or surrogate to consent.
6. Pregnancy

Cardiac surgery patients