Incidence and risk factors for delirium in cardiac surgery intensive care unit patients: A single-center study

Background

Delirium is a frequent and serious complication following cardiac surgery, particularly in patients admitted to the intensive care unit (ICU), where it can negatively impact recovery and outcomes.

Aim

To investigate the incidence, risk factors, and clinical consequences of delirium in post-cardiac surgery ICU patients.

Methods

A total of 202 consecutive patients admitted to the cardiac surgery ICU at the Onassis Cardiac Surgery Center were evaluated for delirium using the Confusion Assessment Method-ICU scale.

Results

Delirium was observed in 29.2% of the cohort and was independently associated with older age, longer total anesthesia/sedation duration, and higher EuroSCORE II. These variables showed poor-to-fair/modest discriminatory ability for delirium prediction. Patients who developed delirium experienced more frequent reintubation, higher rates of ICU-acquired weakness and hemodialysis, prolonged mechanical ventilation, and extended ICU stays.

Conclusion

These findings underscore the multifactorial nature of postoperative delirium and suggest that older age, higher EuroSCORE II, and longer anesthesia exposure are associated with increased delirium risk. However, given the exploratory design and modest discriminatory performance of the identified variables, these findings should not be interpreted as a validated risk prediction tool and require confirmation in larger multicenter studies.