Dexmedetomidine Supplemented Analgesia and Incidence of Postoperative Delirium

Delirium is a frequently occurred cerebral complication in elderly patients after surgery, and its occurrence is associated with worse outcomes. Sleep disturbances is considered to be one of the most important risk factors of postoperative delirium. Previous studies showed that, for elderly patients admitted to the ICU after surgery, low-dose dexmedetomidine infusion improved the quality of sleep and decreased the incidence of delirium. The investigators hypothesize that, for elderly patients after cancer surgery, dexmedetomidine supplemented analgesia can also decrease the incidence of delirium, possibly by improving sleep quality. The purpose of this multicenter, randomized controlled trial is to investigate the impact of dexmedetomidine supplemented analgesia on the incidence of delirium in elderly patients after cancer surgery.

Sex

All

Minimum age

65 Years

Maximum age

90 Years

Inclusion Criteria:

* Age \>= 65 years, \< 90 years;
* Scheduled to undergo curative resection for primary solid organ cancer under general anesthesia, with an expected duration of surgery \>=2 hours;
* Planned to use patient-controlled intravenous analgesia after surgery;
* Provide written informed consent.

Exclusion Criteria:

* Preoperative history of schizophrenia, epilepsy, parkinsonism or myasthenia gravis;
* Preoperative radio- or chemotherapy;
* Inability to communicate in the preoperative period because of coma, profound dementia or language barrier;
* Preoperative obstructive sleep apnea (previously diagnosed as obstructive sleep apnea, or a STOP-Bang score \>= 3 and serum HCO3- \>= 28 mmol/L);
* Brain trauma or neurosurgery;
* Preoperative left ventricular ejection fraction \< 30%, sick sinus syndrome, severe sinus bradycardia (\< 50 beats per minute), or second-degree or above atrioventricular block without pacemaker;
* Severe hepatic dysfunction (Child-Pugh class C) or severe renal dysfunction (requirement of renal replacement therapy before surgery);
* ASA classification \>= IV.

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