Tylman 2011.

Methods	RCT, parallel design, single‐centre
Participants	Total number of randomized participants: 50 Inclusion criteria Scheduled for elective colorectal surgery Exclusion criteria Study authors report that participants with ulcerative colitis and Crohn's disease were excluded after randomization. No other exclusion criteria reported Types of surgery: colorectal surgery for rectal or colon cancer Baseline characteristics TIVA group Age, median (25 to 75% range): 63 (59 to 72) years Gender, M/F: 15/10 ASA grade: not reported Inhalational maintenance group Age, median (25 to 75% range): 70 (59 to 78) years Gender, M/F: 16/9 ASA grade: not reported Country: Sweden Setting: hospital
Interventions	TIVA group Participants: n = 25; 0 losses Induction details : propofol TCI 3 µg/mL. Continuous infusion of remifentanil 0.25 µg/kg/min Maintenance details: propofol 2 µg/mL. Remifentanil 0.15 µg/kg/min Additional regional anaesthesia: epidural anaesthesia of 5 mg/mL bupivacaine, and 5 µg/mL epinephrine at rate of 4 mL to 5 mL during surgery. Postoperatively participants epidural changed to 1 mg/mL bupivacaine, 2 µg/mL fentanyl, 2 µg/mL epinephrine at rate of 5 mL/hour to 12 mL/hour Other information: before induction of anaesthesia participants given 1 µg/kg to 2 µg/kg fentanyl IV, and standard dose of rocuronium Inhalational maintenance group Participants: n = 25; 4 losses (did not meet study inclusion criteria); 21 analysed Induction/maintenance details: sevoflurane with 60% O2 throughout surgery. Concentration not reported. We assume that induction was also with sevoflurane Additional regional anaesthesia: epidural anaesthesia of 5 mg/mL bupivacaine, and 5 µg/mL epinephrine at rate of 4mL to 5 mL during surgery. Postoperatively participants epidural changed to 1 mg/mL bupivacaine, 2 µg/mL fentanyl, 2 µg/mL epinephrine at rate of 5 mL/hour to 12 mL/hour Other information: fentanyl and rocuronium same as TIVA group
Outcomes	Inflammatory markers Blood loss Body temperature Blood glucose levels Length of hospital stay
Notes	Funding/declarations of interest: not reported Study dates: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Participants were randomly assigned to groups; no additional details
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	Unclear risk	No details
Incomplete outcome data (attrition bias) All outcomes	High risk	Loss of participants (all in inhalation group) after randomization because these participants were diagnosed with additional conditions (ulcerative colitis and Crohn's disease). Decision to remove these participants was to avoid confounding. Post‐hoc decision which is imbalanced between groups
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	Unclear risk	Differences in groups in use of remifentanil and fentanyl. Also, study authors do not report concentration of sevoflurane. Note limited information in baseline characteristics table, and lack of inclusion/exclusion criteria