Introduction: Postoperative delirium is one the most common and serious complications that patients develop after undergoing cardiac surgery.

Objective:The present study aimed To investigate the preoperative anxiety and depression of the patients decided to undergo heart bypass surgery and to examine the relationship between these two factors and the incidence of postoperative delirium in the patients.

Materials and Methods: In this cross-sectional research study, as many as 108 patients referred to the surgery department of Heshmat Educational-Therapeutic Center in Rasht, north of Iran, for elective cardiac surgery were targeted. For the purpose of the data collection, the Hospital Anxiety and Depression Scale (HADS), the SpeilbergerState-Trait Anxiety Inventory(STAI), and theMini Mental State Examination (MMSE) were distributed among the patients before they undergo the surgery and a Postoperative Delirium Scale (DOS) was given to them three days after the surgery. The data were then analyzed using descriptive statistics (frequency, mean, and standard deviation) and inferential statistics (independent t-test and chi-square).

Results: On average, delirium was reported in 38% percent of the patients three days after the surgery. It was also discovered that the average age of the patients with delirium was not significantly different from that of those without delirium. Moreover, the findings indicated that the frequency of experiencing delirium was not significantly different among patients in terms of being diabetic and non-diabetic and in terms of their sex, education, life condition, and marital status. State anxiety and trait anxiety were reported in 72% percent and 65% percent of the patients respectively. The frequency of experiencing delirium by the patients with state-trait anxiety as well as hospital anxiety and depression was not significantly different from that of those without disorders. It was shown that 31% of the patients had reported degrees of minor cognitive disorders before the surgery; the frequency of delirium in this group of the patients was not significantly different from the patients without any psychological disorders.

Conclusion: Despite the prevalence of anxiety and depression in the patients before the heart bypass surgery, they did not experience more delirium than the patients without psychological disorders.

Conflict of interest: none declared.