Effect of Opioid-free Anaesthesia on Postoperative Delirium in Elderly Patients Undergoing Gastrointestinal Surgery

Exclusion Criteria

• •1. Refusal to undergo surgery
• •2. Emergency surgery
• •3. Language impairment or severe hearing or visual deficits that hinder effective communication with research or surgical staff
• •4. History of neurological or psychiatric disorders, including Alzheimer's disease (AD), other forms of dementia, stroke, or psychosis
• •5. Long-term use of psychotropic medications (e.g., clozapine, risperidone, olanzapine, haloperidol, chlorpromazine)
• •6. Cardiac or craniocerebral surgery within the past year
• •7. Participation in other interventional clinical studies within the past 3 months
• •8. Preoperative cognitive impairment defined as a modified Telephone Interview for Cognitive Status (TICS-M) score ≤ 27
• •9. Patients will only be enrolled once, even if a subsequent surgery related to the primary procedure is performed