Impact of anesthesia on postoperative cognitive function in older adults: Development of Postoperative Cognitive Dysfunction (POCD) in elderly patients

Abstract

Introduction: Postoperative cognitive impairment (PDP) is a common and significant complication in elderly patients undergoing surgery, associated with higher morbidity, prolonged hospitalization, and increased mortality. Although multiple factors contribute to the development of POCD, the type of anesthesia and techniques used during the surgical procedure play a critical role. This study aims to evaluate the relationship between different types of anesthesia and the development of POCD, identify associated risk factors, and explore potential interventions to minimize this complication in elderly patients. Methods: A systematic review was carried out with analysis of studies published between 2021 and 2024. The search was conducted in the PubMed, Scopus and Web of Science databases, using descriptors related to anesthesia, cognitive dysfunction and elderly patients. Randomized controlled trials, cohort studies, and case-control studies that investigated the incidence of POCD in elderly patients undergoing different types of anesthesia were included. Two independent reviewers selected and extracted data, while the quality of the studies was assessed using the Cochrane Risk of Bias tool and the Newcastle-Ottawa scale. Results: We included 18 studies, covering 6,732 elderly patients. The results showed that general anesthesia with volatile agents, such as sevoflurane and desflurane, was associated with a higher incidence of POCD, ranging between 35% and 40%, compared to intravenous anesthetics, such as propofol (20%). Dexmedetomidine, both as an anesthetic adjunct and for ICU sedation, has been shown to significantly reduce the incidence of POCD. In addition, cognitive prerehabilitation and intranasal insulin administration have also shown efficacy in reducing cognitive decline. Factors such as advanced age, comorbidities, duration of the surgical procedure, and heart rate variability have been identified as significant predictors of POCD. Conclusion: The choice of the type of anesthesia and the implementation of specific interventions can significantly reduce the risk of POCD in elderly patients. Intravenous anesthetics, such as propofol, and adjuvants such as dexmedetomidine, showed benefits in cognitive outcomes. Strategies such as cognitive prerehabilitation and intranasal insulin administration have also been shown to be effective. Personalization of the anesthetic approach, taking into account individual risk factors, is essential to optimize outcomes in this population.