Assessment of the impact of frailty and geriatric syndromes on postoperative cognitive functions in geriatric patients

Introduction and Objectives: As individuals age, physiological changes and declines in organ functions, collectively known as frailty, become apparent. When these individuals are hospitalized or undergo surgery for various reasons, cognitive impairments may also accompany this condition. It is well-established that preoperative frailty is associated with adverse postoperative outcomes. The origin of cognitive impairments observed in elderly individuals remains a topic of debate, whether they stem from hospitalization, the type of anesthesia, and/or the surgery itself. Our study aimed to investigate the risk factors influencing postoperative cognitive dysfunction (POCD) and explore the impact of frailty and geriatric syndromes on POCD. Methods: After obtaining approval from the Aydın Adnan Menderes University Faculty of Medicine Clinical Research Ethics Committee, 305 volunteer patients aged 65 and over, literate, and classified as ASA I-II-III risk groups were included in the study. Patients with psychiatric and neurological disorders, drug dependencies, those undergoing emergency surgery, cardiac surgery, intracranial surgery, and postoperative intubation were excluded from the study.The cases were divided into four groups and classified as follows: Group 1, control group patients presenting to the outpatient clinic; Group 2, patients receiving inpatient treatment in internal medicine departments; Group 3, patients undergoing surgical procedures under spinal anesthesia; Group 4, patients undergoing surgical procedures under general anesthesia. Frailty was assessed using the Frailty Frailty Scale and Modified Frailty Index, while cognitive status was evaluated using the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) tests during the initial encounter for all patients. Except for the control group, MMSE and MoCA tests were administered on the third day to assess differences in cognitive functions. The diagnosis of POCD was made using the '1 Standard Deviation Rule'. The standard deviation of the cognitive function tests administered on the first day was calculated and compared with the cognitive function tests administered on the third day. A decrease of more than 1 standard deviation was interpreted in favor of POCD. Additionally, demographic information including age, weight, height, education level, chronic illnesses, medications used, history of depression, existing geriatric syndromes, and operation-related details were recorded for all cases. Results: To identify variables influencing POCD, initially, univariate logistic regression analysis was conducted. Univariate logistic regression revealed that age, chronic illnesses, geriatric syndromes, ASA score, and frailty status increased the risk of POCD. As these risk factors are interrelated and influence each other (e.g., chronic illnesses with ASA score), multivariate logistic regression analysis was performed with these variables. The results of the multivariate logistic analysis indicated that age, ASA score, and frailty increased the risk of POCD. In elderly individuals (aged 75-84), the risk of POCD was 3.526 times higher (p=0.001) compared to younger elderly individuals (aged 65-74), while in very elderly individuals (aged 85 and above), the risk of POCD was 11.653 times higher than in younger elderly individuals (p=0.003). Patients with ASA score III had a 3.298 times higher risk of POCD compared to those with ASA score I (p=0.028). The risk of POCD was 4.166 times higher in patients classified as pre-frail according to the Frailty Scale compared to normal individuals (p=0.005), while frail patients had a 11.288 times higher risk compared to normal individuals (p<0.001). Conclusion: In our study, it was found that approximately 50% of cases had cognitive dysfunction on the postoperative 3rd day. When examining the factors affecting POCD, it was observed that geriatric syndromes increased the risk of POCD according to the results of univariate logistic regression analysis, but their effect on the development of POCD was not observed according to the results of multivariate logistic regression analysis. Additionally, a significant relationship was found between advanced age, frailty status, high ASA scores, and POCD. Considering that the presence of chronic illnesses is associated with frailty and high ASA scores, we believe that it increases the risk of postoperative cognitive dysfunction. In this context, we believe that even if elderly patients are not evaluated with frailty scales, the presence of a high number of chronic illnesses in an individual should be considered as a potential risk factor for postoperative cognitive impairment. Looking at the results of our study, we believe that it is important, especially in elderly individuals, to use frailty tests if possible in routine preoperative evaluation to predict and prevent POCD. If not possible, querying the individual's multiple comorbidities and administering easily applicable tests such as the clock drawing test to gain insight into cognitive status can help identify patients at risk of cognitive dysfunction. We need to be aware that cognitive dysfunction may develop in these patients. Keywords: Geriatrics, Geriatric Syndromes, Frailty, Neurocognitive Tests, Postoperative Cognitive Dysfunction