Background and Goal of Study: 
Postoperative delirium (PD) after cardiac surgery is a major problem and results in increased morbidity. Studies have suggested that a sevoflurane-based anesthesia was better associated with short-term cognitive function than propofol.1We sought whether the choice of the anesthetic agent could influence the incidence of PD in a cohort of patients undergoing all types of cardiac surgery with or without cardiopulmonary bypass.
Materials and methods: 
This is a sub analysis of a large prospective observational trial evaluating the neurologic outcome of adult patients undergoing cardiac surgery (NCT02006212).A total of 1500 patients will be included for the purposes of the study.In all patients cerebral oxygen saturation (ScO2) is measured at baseline. Subjects are evaluated for PD during the entire hospital stay. At the ward, the evaluation is performed every 4 to 6 hours. No standard screening tests are used. However, signs and symptoms of hypoactive, hyperactive and mixed delirium are detected.Data are expressed in median (P25-P75) or numbers and percentages. A Mann-Whitney and a Chi square test are used to compare respectively continuous and dichotomous variables between both groups.A binary regression analysis was performed to predict PD. The type and the total dosis of anesthetic agents were considered as independent variables. P< 0,05 is considered significant.
Results and discussion: 
620 patients were analyzed. PD occurred in 20% of the patients. Patients´ characteristics are illustrated in table 1. 

 	PD (N=126)	No PD (N=494)	P
Age (Years)	74 (64-80)	67 (57-75)	< 0,001
Baseline mean Sc02 (%)	61 (56-67)	63 (56-69)	0,013
Surgery with open left cavities	87 (69%)	321 (65%)	0,54
Sevoflurane	84 (67%)	322 (65%)	0,84
Midazolam	121(96%)	477 (97%)	0,04
Total dose midazolam per weight (mg/kg)	0,048 (0,033-0,060)	0,048 (0,034-0,058)	0,82
Ketamine	106 (84%)	443 (65%)	0,01
Total dose Ketamine per weight (mg/kg)	0,36 (0,24-0,48)	0,38 (0,26-0,47)	0,55
[Patients' characteristics with or without PD]

The Hosmer-Lemeshow test was positive (P =0,552). Age was the only independent predictor of PD: Odds-Ratio:1,039(95% CI:1,021-1,058), P=0,000.
Conclusion(s): 
This is the first large prospective study evaluating the impact of the anesthetic regimen on the incidence of PD. Our preliminary results show that the choice of the anesthetic agent does not influence the incidence of PD after cardiac surgery. Age remains the only independent predictor. 
References: SchoenJ et al. BJA 2011

The choice of anesthetic agent does not predict the occurrence of postoperative delirium after cardiac surgery: a prospective observational study