NCT02662257.

Trial name or title	Impact of anaesthesia maintenance methods on incidence of postoperative delirium
Methods	RCT, parallel design
Participants	Target number of randomized participants: 1200 Inclusion criteria ≥ 65 years and < 90 years of age Primary malignant tumour Not receiving radiation therapy or chemotherapy before surgery Scheduled to undergo surgery for the treatment of tumours, with an expected duration of ≥ 2 hours, under GA Agree to participate, and give signed written informed consent Exclusion criteria: Preoperative history of schizophrenia, epilepsy, parkinsonism or myasthenia gravis Inability to communicate in the preoperative period (coma, profound dementia, language barrier, or end‐stage disease) Critical illness (preoperative ASA ≥ IV) Severe hepatic dysfunction (Child‐Pugh class C) Severe renal dysfunction (undergoing dialysis before surgery) Neurosurgery Other reasons that are considered unsuitable for participation by the responsible surgeons or investigators Type of surgery: treatment of tumour Country: China Setting: hospital
Interventions	TIVA group Details: propofol adjusted to maintain BIS 40 to 60, with or without 50% nitrous oxide. Remifentanil (administered by continuous infusion), sufentanil (administered by intermittent injection/continuous infusion), or fentanyl (administered by intermittent injection). Towards the end of surgery, propofol infusion rate will be decreased and fentanyl/sufentanil will be administered when necessary Inhalational maintenance group Details: sevoflurane adjusted to maintain BIS 40 to 60, with or without 50% nitrous oxide. Remifentanil (administered by continuous infusion), sufentanil (administered by intermittent injection/continuous infusion), or fentanyl (administered by intermittent injection). Towards the end of surgery, sevoflurane inhalational concentration will be decreased and fentanyl/sufentanil will be administered when necessary
Outcomes	Delirium (using CAM or CAM‐ICU, at 7 days postoperatively) Length of hospital stay (up to 30 days) Incidence of non‐delirium complications (up to 30 days) Cognitive function (using TICS‐m at 30 days) All‐cause 30‐day mortality Pain score (during first 3 days postoperatively) Cognitive function at 7 days postoperatively
Starting date	April 2015
Contact information	Dong‐Xin Wang, MD, PhD, Peking University FIrst Hospital
Notes	Also registered as ChiCTR‐IPR‐15006209