The Relation between Post Cardiac Surgery Delirium and Intraoperative Factors

Introduction & Delirium is an acute mental state, characterized by disturbed consciousness and cognitive dysfunction occurring in the setting of a physiological derangement, caused by a medical disorder. Cognitive decline after cardiopulmonary bypass (CPB) surgery, especially in the elderly patients, is of significant concern, since the advent of CPB procedures. Most prospective neuropsychological studies also found postoperative cognitive decline, early after surgery. Nowadays the incidence of postoperative delirium is more than 90% in some reports. Recently, the rate of cardiac surgeries has risen in the aged population, and the social and economic impacts of these complications has increased. We are about to evaluate the relationship between the incidence of delirium after heart surgery and some of the intraoperative factors. During 6 months in a university-affiliated hospital, 250 patients of over 50 years old, who were elected for CABG surgery, enrolled in the study. All patients were examined preoperatively and in the second and seventh postoperative days as well; with a comprehensive neuropsychological and neuropsychiatry assessment; (mini-mental-state examination). DSM-IV was also used to confirm the diagnosis. In this study, the incidence of delirium after open heart surgery was 47%. This study indicates that delirium after heart surgery is associated with CPB time>120 minutes, cross-clamp time>75 minutes, intraoperative HTC<30% and intraoperative temperature<30°C. There was no relationship between EuroScore and Delirium. Although the origin of the postoperative neuropsychological alterations is unclear, the present data suggests an association between some factors and postoperative delirium, and its knowledge can help us to prevent or cure this complication. Yet, a continuous investigation for the prevention of postoperative Delirium incidence and its treatment is essential.