Cerebral Oxygen Consumption Response to Increased Oxygen Supply and Postoperative Delirium in Older Surgical Patients

The goal of this observational study is to learn whether the brain's ability to use oxygen during surgery is associated with postoperative delirium in adults aged 65 years and older undergoing general anesthesia. The main question it aims to answer is: \- Does reduced cerebral oxygen consumption responsiveness during surgery increase the risk of postoperative delirium in older patients? Participants who are undergoing elective laparoscopic surgery under general anesthesia as part of their routine medical care will have brain oxygen levels measured during surgery using a non-invasive forehead sensor, and will be assessed for delirium for up to three days after surgery.