Incidence and risk factors of delirium in patients after cardiac surgery: Modifiable and non-modifiable factors

a b s t r a c t Background: Post cardiac surgery delirium is a severe complication. This study tried to evaluate the early postoperative delirium risk factors and to identify which of them can be modified in order to optimize perioperative management. Methods: It is a prospective observational study. 250 consecutive cardiac surgery patients took part in the study. Cardiac surgery, the anesthetic regiment and the postoperative management were standardized. The incidence and the risk factors of the postoperative delirium were analyzed by univariate and multivariate analysis. Delirium was assessed with screening scale – The Confusion Assessment Method for the intensive care unit every 12 h postoperatively. Results: Delirium developed in 52 patients (20.8%). Univariate analysis of the variables confirmed that older age ( p = 0.0001), the higher EuroSCORE II value ( p = 0.0001), longer CPB time ( p = 0.0001), longer ACC time ( p = 0.0001), and the sufentanil dose ( p = 0.010) were strongly independently associated with postoperative delirium. The benzodiazepine administration was shown to be an intermediate predictor for developing postoperative delirium ( p = 0.055). Conclusions: Advanced age, higher EuroSCORE II value, longer CPB and ACC times, and higher sufentanil doses during anesthesia were all predictors for the development of postoperative delirium. The only modifiable risk factor was the use of larger doses of sufentanil which is related with the duration of the operation. New preventive strategies and use of reduced dose of sufentanil intraoperatively, or the use of different opioid should be studied and applied in order to reduce the incidence of the postoperative delirium.