The Effect of Oxytocin Nasal Spray on Preventing Postoperative Delirium in Elderly Patients Undergoing Orthopedic Surgery

Elderly patients undergoing orthopedic surgery under general anesthesia Inclusion criteria: 1. Age ≥ 65 years; 2. Patients who were to undergo elective orthopedic surgery under general anesthesia with tracheal intubation; 3. ASA class I-III; 4. Estimated duration of surgery ≥ 1 hour; (5) The patient himself/herself or his/her legal representative; 5. Informed consent from the patient or legal representative; 6. Proficiency in the use of Chinese language for communication. Exclusion criteria: 1. Nasal cavity occupation, patients with fillers in the nose 2. Oxytocin allergy; 3. Patients with previous psychiatric and neurological disorders, such as depression, severe central nervous system depression, Parkinson's disease, basal ganglia disease. Goldson's disease, basal ganglia lesions, schizophrenia, epilepsy, Alzheimer's disease, myasthenia gravis, and so on; 4. Pregnant and lactating women 5. Patients with severe hepatic insufficiency (Child-Pugh class C); 6. patients with severe renal insufficiency (dialysis is required before surgery) 7. Severe heart failure (METS\<4); 8. Preoperative inability to communicate (coma or dementia); 9. Severe preoperative blindness, deafness, or inability to understand Mandarin to complete preoperative delirium screening; 10. Preoperative cognitive impairment as determined by a MoCA evaluation prior to surgery; 11. Patients who are scheduled for 2 surgeries within 7 days of surgery; 12. Patients with bone malignancy 13. Currently participating in other clinical trials.