Effects of Intraoperative Targeted Temperature Management on Incidence of Postoperative Delirium and Long-term Survival

Intraoperative hypothermia is common in patients having major surgery and the compliance with intraoperative temperature monitoring and management remains poor. Studies suggest that intraoperative hypothermia is an important risk factor of postoperative delirium, which is associated with worse early and long-term outcomes. Furthermore, perioperative hypothermia increases stress responses and provokes immune suppression, which might promote cancer recurrence and metastasis. In a recent trial, targeted temperature management reduced intraoperative hypothermia and emergence delirium. There was also a trend of reduced postoperative delirium, although not statistically significant. This trial is designed to test the hypothesis that intraoperative targeted temperature management may reduce postoperative delirium and improves progression-free survival in older patients recovering from major cancer surgery.

Inclusion Criteria: 1. Age ≥65 years. 2. Planned potentially curative initial cancer surgery with an expected duration of 2 hours or longer under general anesthesia. Exclusion Criteria: 1. Preoperative fever (tympanic temperature ≥38℃). 2. Known or suspected preoperative infection. 3. Previous history of schizophrenia, epilepsy, Parkinson disease, myasthenia gravis, or delirium. 4. Unable to communicate due to severe dementia, language barrier, or coma. 5. Critically ill (Left ventricular ejection fraction \IV, or expected survival \30 kg/m2 (to facilitate thermal management). 9. Have participated in this study previously. 10. Any other conditions that are considered unsuitable for study participation.