Investigators propose this multi-center randomised controlled study to test the preventive effect of intravenouse acetaminophen in delirium over 5 postoperative days among older patients recovering from major non-cardiac surgery.
Age ≥ 65 years.
Scheduled for non-cardiac major surgery with general anesthesia that is expected to last more than 2h.
ASA Physical Status I-III.
Weight >50 kg.
Pre-existing neuropsychiatric diseases (Alzheimer's disease, Schizophrenia, Parkinson's Disease, Seizures, etc.).
Pre-existing cognitive impairment (MMSE<18).
Preoperative delirium.
Severe circulatory instability (preoperative left ventricular ejection fraction less than 30%, unstable angina, severe coronary artery disease, sick sinus syndrome, etc.).