Methods: The study included 55 patients who were hospitalized in the cardiovascular surgery ICU of a university hospital. Between March 2008 and April 2009, the study data were collected using the patient information form prepared by the researchers, confusion evaluation method in ICU, Glasgow coma scale (CKS), Richmond agitation sedation scale (RASS), acute physiology and chronic health evaluation (APACHE II) and simplified therapeutic intervention scoring system (TISS-28). Data were analyzed with chi-square, Fischer exact chi-square, t-test, and Mann-Whitney U-test.

Results: Delirium occurred in 18.2% (n=10) of the patients. Eighty percent of the patients in which delirium developed had hypoactive type. The points of APACHE II, RASS, TISS-28 among ICU scores increased in the group with delirium. The mortality rate of the patients with delirium was higher compared to the patients without delirium. However, the difference was statistically significant. The length of stay in the ICU was also longer for the patients with delirium.

Conclusion: Delirium is a more common pathology than estimated in cardiovascular surgery intensive care patients, particularly presenting with hypoactive type. Nurses have important roles and responsibilities in determining the signs of delirium in patients in the ICU in early stages. Therefore, educating nurses on using delirium assessment scales is essential for the safety of patients and increasing quality of care.