Evaluation of the prevalence and risk factors of delirium in cardiac surgery ICU.

Introduction: Delirium is defined as an acute cognitive disorder presenting with fluctuation in cognition, apathy and non-organized thinking. It may increase morbidity, mortality, ICU stay and cost. In patients who underwent heart surgery delirium may increase post-operative complications such as respiratory insufficiency, sternum instability and need to re-operation of the sternum. The aim of this study was to evaluate the prevalence and risk factors of delirium in patients admitted to cardiac surgery.

Materials And Methods: 18 years or older patients who had undergone cardiac surgeries and stayed for more than 24 hours in ICU following surgery were recruited. All subjects were assessed for signs & symptoms of delirium using CAM-ICU and its risk factors. All data were analyzed by SPSS 16 at the end of the study.

Results: The prevalence of delirium in these patients was 23.5% (47 patients). The mean age of patients with delirium was more than other patients (P=0.001). The Incidence of delirium in the patients with cardiopulmonary bypass surgery (CPB) was higher than the patients without CPB (P=0.01). The Incidence of delirium in the patients with Atrial fibrillation was higher than patients without it (P=0.002). The Incidence of delirium in the patients with CVA history was higher than the patients without CVA history (P=0.032). The mean time of mechanical ventilation in the delirious patients was more than other patients (P=0.01).

Conclusion: Older Age, CPB, history of CVA, Atrial Fibrillation, and prolonged mechanical ventilation are considered as the risk factors of delirium in cardiac surgery patients.