Tang 2014.

Methods	RCT, parallel design, single‐centre
Participants	Total number of randomized participants: 220 Inclusion criteria Elderly patient with MCI, ≥ 60 years of age, ASA I to III, scheduled for radical rectal resection surgery Exclusion criteria Current diagnosis of dementia (pre‐operative MMSE score 23) Current or past psychiatric illness; current use of antidepressant of antianxiety medication History of drug dependence or alcohol abuse History of coronary artery, peripheral arterial or cerebrovascular disease Severe visual, auditory, or motor disability Acute infection Preoperative haemoglobin 85 g/L Type of surgery: radical rectal resection surgery Baseline characteristics TIVA group Age, mean (SD): 69.6 (± 4.8) years; 41 patients were ≥ 70 years of age Gender, M/F: 26/75 ASA grade: not reported Inhalational maintenance group Age, mean (SD): 70.0 (± 4.3) years; 41 patients were ≥ 70 years of age Gender, M/F: 32/67 ASA grade: not reported Country: China Setting: hospital
Interventions	TIVA group Participants: n = 110; 9 losses (declined to participate in follow‐up at day 7); 101 analysed Induction details: midazolam 0.03 mg/kg to 0.04 mg/kg IV, fentanyl 0.002 mg/kg to 0.003 mg/kg IV, vecuronium 0.15 mg/kg to 0.2 mg/kg. Then propofol 1.5 mg/kg to 2 mg/kg IV Maintenance details: propofol 6 mg/kg/hour to 10 mg/kg/hour. To maintain BIS 30 to 60. Remifentanil 9 µg/kg/hour to 12 µg/kg/hour continuous IV infusion, vecuronium intermittent IV infusion Other information: all patients had PCI 150 mL saline with fentanyl 1.5 mg, tropisetron 12 mg, infusion rate 2 mL/hour, with 15‐minute lockout Inhalational maintenance group Participants: n = 110; 11 losses (declined to participate in follow‐up at day 7); 99 analysed Induction details: midazolam 0.03 mg/kg to 0.04 mg/kg IV, fentanyl 0.002 mg/kg to 0.003 mg/kg IV, vecuronium 0.15 mg/kg to 0.2 mg/kg. Then 8% sevoflurane (fresh gas flow 6 L/min, decreased to 3% to 4% after loss of consciousness with fresh gas flow 1 L/min to 2 L/min) Maintenance details: sevoflurane 2% to 3%. To maintain BIS 30 to 60. Remifentanil 9 µg/kg/hour to 12 µg/kg/hour continuous IV infusion, vecuronium intermittent IV infusion Other information: analgesics same as TIVA group
Outcomes	POCD Anaesthesia duration Dose of remifentanil and atropine Hypotension Haemodynamic variables Pain (using VAS) Wound infection Pneumonia
Notes	Funding/declarations of interest: study authors report that authors received no specific grant from any funding agency in the public, commercial or not‐for‐profit sectors Study dates: January 2010 to November 2013
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Use of computer‐generated, blocked random‐allocation sequence
Allocation concealment (selection bias)	Unclear risk	No details
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not feasible to blind anaesthetist to intervention groups
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "to ensure blinding, neuropsychological assessment work was carried out by a physician trained in psychology. Neither the physician nor the patient knew which anaesthetic had been used during surgery"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Some loss of participant data at about 10%. It is unclear whether this loss could influence outcome data.
Selective reporting (reporting bias)	Unclear risk	Study authors do not report clinical trials registration. Not feasible to judge risk of selective outcome reporting
Other bias	Low risk	No other sources of bias identified.