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

The primary outcome will be delirium occurring on postoperative day one. Delirium will be assessed using the Confusion Assessment Method (CAM) twice daily. Delirium will be defined as present if either the morning or afternoon assessment are positive for delirium.

Postoperative delirium will also be assessed as a secondary outcome assessed within the first three days after surgery, and separately within the first seven days following surgery. Delirium will be assessed using the CAM in the same fashion as the primary outcome. In the event the patient is reintubated the CAM-ICU may also be used to assess for postoperative delirium as a secondary outcome.

Delirium severity will be assessed using the CAM-Severity (CAM-S) within the first three days following surgery, and separately within the first seven days following surgery. The CAM-S ranges from 0 (no delirium features) to 19, with higher scores indicating worsening delirium severity.

Global cognitive function will be assessed with the T-MoCA in-hospital and at three time points after hospital discharge. Different versions of the T-MOCA will be administered at each time point to minimize learning effects. The T-MoCA ranges from 0 (worst) to 22 (best) points, does not require visual cues or writing, and importantly, can be administered over the phone.

Global health will be assessed at 30, 180 and 365 days using the Patient Reported Outcome Measurement Information System (PROMIS) 29 Profile version 2.1. This assessment results in several subscale scores, each reported as a t-score.

Pain will be assessed within the first seven days following surgery, using a trajectory of pain scores at rest and upon exertion/deep breathing. Pain scores will be elicited from patients daily using the Pain Numeric Rating Scale.

Outcomes for opioid administration will evaluate the (a) frequency and (b) total consumption, defined as morphine equivalents, in the first 24 and 48 hours postoperatively. These will be captured based off medical record review.

Hospital length of stay will be defined as the number of days after surgery until the time of discharge from the hospital.

Intensive Care Unit (ICU) length of stay will be calculated as the time from discharge from the initial index ICU stay minus the time of admission into the cardiovascular ICU and will be reported in hours.

Hospital readmission will be evaluated within the first 30 days postoperatively using the Society for Thoracic Surgery database or via patient report during follow up phone calls.

Major cardiac events will be evaluated within 30 days postoperatively and include stroke, atrial fibrillation and renal failure. These outcomes will be assessed using the Society for Thoracic Surgery database and medical record review.

All-cause mortality will be assessed in-hospital and at 30, 180 and 365 days postoperatively. Mortality will be assessed using a combination of electronic medical record review, Society for Thoracic Surgery database, and family report during the follow up phone calls.