Preoperative risk factors for the development of postoperative delirium in cardiac surgery. Relevance of the gerontological approach (a systematic review of foreign literature on the ScR methodology)

Introduction. The large number of cardiac surgeries currently performed worldwide raises safety concerns, including the risk of postoperative delirium in the early postoperative period. Objective: to clarify current understanding of preoperative risk factors for postoperative delirium in patients over 55 years of age who have undergone cardiac surgery, to inform the develop-ment of prevention programs for this condition in adults, the elderly, and the older. Materials and Methods. A systematic review of relevant literature was conducted using the Scoping Review (ScR) methodology to obtain information on concepts, sources of evidence, and research gaps. The study included scientific publications searched through the PubMed biomedical research search engine and selected using the following keywords: postoperative delirium, cardiac surgery, risk factors, the elderly, and elective cardiac surgery. Results. Postoperative delirium is a polygenic disorder; its development preoperatively is determined by the involvement of the central acetylcholine system, neuroinflammation, brain energy deprivation, frailty, and preoperative mental disturbances. Age is a universal predictor, encompassing the contribution of other preoperative factors to the development of postoperative delirium in elderly cardiac surgery patients. We believe that old age, comorbidity with other pathological conditions, and decrease in the sanogenic protective mechanism of cerebral-cognitive reserve make the brain of the elderly nonspecifically vulnerable. We consider postoperative delirium as an aberrant stress response caused by the dys-function of vulnerable brain adaptation systems in response to the stressor – cardiac surgery. Based on these concepts, the goal of prediction is to identify and explore vulnerability factors, correct them preoperatively, and maintain cerebral-cognitive re-serve. In the elderly patients, this is possible with the use of a general gerontological approach.