The Cognitive Functions in Patients With Postoperative Delirium Undergoing Cardiac Surgery After ICU Discharge

Background: Postoperative delirium (POD) is a neurobehavioral disorder that occurs during intensive care unit (ICU) admission. There is a lack of knowledge about POD and cognitive functions in cardiac surgery (CS) patients. Objectives: To describe the impact of POD on cognitive function in patients undergoing CS after discharge from the ICU. Methods: A systematic review followed the PRISMA guidelines. The inclusion criteria were studies explaining the relationship between POD and cognitive functions, while we excluded secondary studies, studies on dementia, and studies using languages other than English. This review was registered in the PROSPERO database (ID: CRD42024560306). Results: A total of 2540 records were screened. We included 10 studies. Eight studies reported evidence of level 3 (OCEBM level), and 4 had high methodological quality (JBI score). Four studies reported POD as a significant independent risk factor for cognitive impairment after CS. Four studies reported a positive association between POD and cognitive function 1 month after discharge, 3 studies reported it at 6 and 12 months after discharge, and 2 studies showed the effects on cognitive function at 36 months. The cognitive functions most affected in the patients who developed POD were memory, orientation, concentration, visual construction, language, and attention. Conclusions: POD in patients with CS is a widespread problem that negatively affects cognitive function after ICU discharge. Patients undergoing CS and caregivers shared vital data on cognitive impairments after ICU admission. Their long-term participation highlighted postoperative delirium’s impact, stressing the need for improved care.