The study by Moller et al. (1998) investigated long-term postoperative cognitive dysfunction in elderly patients following major non-cardiac surgery. The International Study of Post-Operative Cognitive Dysfunction (ISPOCD1) involved 1218 patients aged 60 years and older, who completed neuropsychological tests before and at one week and three months after surgery. Oxygen saturation and blood pressure were continuously monitored during and after surgery. The study found that 25.8% of patients had cognitive dysfunction one week postoperatively, and 9.9% at three months, compared to 3.4% and 2.8% in UK controls, respectively. Increasing age, longer anesthesia duration, lack of education, a second operation, postoperative infections, and respiratory complications were risk factors for early postoperative cognitive dysfunction, while only age was a risk factor for late postoperative cognitive dysfunction. Hypoxemia and hypotension were not significant risk factors at any time. The findings suggest that anesthesia and surgery cause long-term cognitive decline in the elderly, with age being a major risk factor. The study highlights the need for further research into the causes and prevention of postoperative cognitive dysfunction, as well as the importance of providing patients with appropriate information before surgery.The study by Moller et al. (1998) investigated long-term postoperative cognitive dysfunction in elderly patients following major non-cardiac surgery. The International Study of Post-Operative Cognitive Dysfunction (ISPOCD1) involved 1218 patients aged 60 years and older, who completed neuropsychological tests before and at one week and three months after surgery. Oxygen saturation and blood pressure were continuously monitored during and after surgery. The study found that 25.8% of patients had cognitive dysfunction one week postoperatively, and 9.9% at three months, compared to 3.4% and 2.8% in UK controls, respectively. Increasing age, longer anesthesia duration, lack of education, a second operation, postoperative infections, and respiratory complications were risk factors for early postoperative cognitive dysfunction, while only age was a risk factor for late postoperative cognitive dysfunction. Hypoxemia and hypotension were not significant risk factors at any time. The findings suggest that anesthesia and surgery cause long-term cognitive decline in the elderly, with age being a major risk factor. The study highlights the need for further research into the causes and prevention of postoperative cognitive dysfunction, as well as the importance of providing patients with appropriate information before surgery.