Retrospective analysis of comparison between intraoperative infusion of Dexmedetomidine and Propofol for postoperative delirium in elderly cardiac surgery on cardiopulmonary bypass

STUDY OBJECTIVE:
To determine whether using dexmedetomidine intraoperatively is associated with fewer postoperative delirium (POD) in elderly cardiac surgery on cardiopulmonary bypass (CPB).
DESIGN:
Retrospective study.
SETTING:
Urban academic hospital.
MEASUREMENTS:
Thirty-four eligible elderly patients (> 70-years-old) who underwent elective cardiac surgery on CPB between December 2014 and October 2015 were randomly divided prospectively into two group. Patients received either intraoperative infusion of dexmedetomidine (DEX group; 0.4-0.6μg/kg/hr, n=17) or propofol (PRO group; 3-5 mg/kg/hr, n=17) and carotid ultrasound scanning were performed preoperatively in both group. Intraoperative cerebral oxygenation was assessed by the tissue oxygenation index (TOI) using near-infrared spectroscopy (NIRS). The absolute value of the difference (mean value of right TOI during CPB minus mean value of left TOI during CPB) (R-L mD) were calculated in both group. Delirium was assessed with the Confusion Assessment Method (CAM) for ICU.
RESULTS:
Patients suffered from a carotid stenosis (CS) in 8 (47.1%) and 3 (17.6%) cases in DEX and PRO groups, respectively. There was no difference in the incidence of POD between the DEX group (8 of 17 patients, 47.06%) and the PRO groups (5 of 17 patients, 29.41%) (P>0.05). However, in the POD group, patients with CS were present in 4 of 8 (50%) and 0 of 3 (0%) patients in DEX and PRO groups, respectively. It seems that this disadvantage of carotid stenosis is directly related to POD in the DEX group. In contrast, increased “R-L mD” values were significantly associated with POD (P = 0.024). In particular, it was found to be significantly increased the “R-L mD” values in the PRO group. 
CONCLUSION: 
This study suggests that intraoperative infusion of DEX is not associated with significantly lower rates of POD in elderly cardiac surgery on CPB. Instead, using DEX intraoperatively correlated significantly with POD in elderly patients who suffered from a CS.
 References: 
Djaiani G1, Silverton N, Fedorko L, Carroll J, Styra R, Rao V, Katznelson R. Dexmedetomidine versus Propofol Sedation Reduces Delirium after Cardiac Surgery: A Randomized Controlled Trial. Anesthesiology. 2015 Nov 16. 
Park JB, Bang SH, Chee HK, Kim JS, Lee SA, Shin JK. Efficacy and safety of dexmedetomidine for postoperative delirium in adult cardiac surgery on cardiopulmonary bypass. Korean J Thorac Cardiovasc Surg. 2014 Jun;47(3):249-54.

Retrospective analysis of comparison between intraoperative infusion of dexmedetomidine and Propofol for postoperative delirium in elderly cardiac surgery on cardiopulmonary bypass