Dexmedetomidine Supplemented Analgesia and Incidence of Postoperative Delirium

Patients in this group will receive patient-controlled intravenous analgesia for 3 days after surgery. The formula is a mixture of dexmedetomidine (1.25 ug/ml) and morphine (0.5 mg/ml), diluted with normal saline to 160 ml. 5-HT3 receptor antagonist is added when necessary. The analgesic pump is set to administer a background infusion at a rate of 1 ml/h, with a bolus dose of 2 ml each time and a lockout time from 6 to 8 minutes according to patients' condition.

Patients in this group will receive patient-controlled intravenous analgesia for 3 days after surgery. The formula is morphine (0.5 mg/ml) diluted with normal saline to 160 ml. 5-HT3 receptor antagonist is added when necessary. The analgesic pump is set to administer a background infusion at a rate of 1 ml/h, with a bolus dose of 2 ml each time and a lockout time from 6 to 8 minutes according to patients' condition.