[Postoperative delirium in the elderly]

Postoperative delirium (POD) is a disorder of attention and consciousness accompanied by cognitive impairment as a direct consequence of a medical condition, the action (or discontinuation) of a drug, toxin, psychoactive substance or the simultaneous action of several factors. To describe the current state of knowledge on delirium, the Medline PubMed database was searched for full-text articles from the years 2000-2025 using the keywords: "postoperative delirium," "prediction" and "elderly." Fifty-six articles were selected for the final analysis. Risk factors for POD are: older age, sensory impairment, alcohol consumption, pre-existing disorders (cognitive, psychomotor activity, sleep-wake rhythm, emotional) and depression. The risk of developing POD can be assessed using questionnaires. Conditions associated with an elevated risk of developing POD include hypertension, history of myocardial infarction and other cardiovascular diseases, anaemia, diabetes, renal failure, urinary incontinence and other micturition disorders. The development of perioperative risk assessment questionnaires (American Society of Anesthesiologists Physical Status Classification System, Charlson Comorbidity Score) is based on the presence of comorbidities. In addition to conventional analysis, machine learning and artificial intelligence has emerged as a novel approach to POD risk factors analysis. Markers of delirium are: inflammatory markers (interleukin 6, neutrophil to limphocyte ratio [NLR] ≥3.5, platelet to lymphocyte ratio [PLR] >139, high CRP concentration), markers of brain tissue damage (D-ribose, plasminogen activator inhibitor-1, tau protein, S100A12 protein, uric acid), markers of blood-brain barrier damage (urinary albumin, fasting glucose), and many others. The risk of POD can be estimated by ultrasound or computed tomography scan (the cross-sectional diameter of the quadriceps or lumbar muscle) and by electroencephalography. Trigger factors may include major surgery, hypotonia, intraoperative blood transfusion, and the need for intra-aortic counterpulsation. There is no procedure to determine the certain development of delirium. The search for better methods should continue. Recognising the risk of delirium allows earlier preventive measures to be taken and its consequences to be reduced. Med Pr Work Health Saf. 2025;76(3):209-215.