Prevalence and Risk Factors of Postoperative Delirium in Patients Undergoing Open Heart Surgery in Northwest of Iran

Delirium as a relatively common complication following cardiac surgery remains a contributory factor in postoperative mortality and an obstacle to early discharge of patients. In the present study 329 patients who underwent open heart surgery between 1st January 2008 to 1st January 2009 in Shahid Madani Heart Center, Tabriz, Iran were enrolled. Overall 4.9% of patients developed delirium after cardiac surgery. We found atrial fibrillation (P = 0.005), lung diseases (P = 0.04) and hypertension (P = 0.02) to be more common in patients who develop delirium postoperatively. Furthermore, the length of intensive care unit (ICU) stay, cardiopulmonary bypass (CPB) time, and ventilation period were also significantly increased. Also a statistically meaningful relationship between the female gender and development of delirium was also noted (P = 0.02). On the other hand no meaningful relationship was detected between diabetes, history of cerebral vascular diseases, peripheral vascular diseases, myocardial infarction, development of pneumonia following surgery, and laboratory levels of sodium, potassium, glucose, and complete blood cell count (CBC) including white blood cells, red blood cells, platelets in the blood-hemoglobin and hematocrits. Also environmental factors like presence of other patients or companion with the patient, and objects like clock, window and calendar in the patient’s room did not affect prevention of delirium. Based on this and other investigations, it can be suggested to use MMPI test to recognize pathologic elements to prevented delirium after surgery and complementary treatment for coping with delirium.