Deng 2009.

Study characteristics
Methods	Randomised, double‐blind, placebo control
Participants	N = 200, about 43% women
Interventions	Pre‐incisional ketamine 0.5 mg/kg bolus IV + 0.1 mg/kg/h infusion IV during surgery and for 24 h postoperatively Pre‐incisional ketamine 0.5 mg/kg bolus IV + 0.05 mg/kg/h infusion IV during surgery and for 24 h postoperatively Pre‐incisional ketamine 0.5 mg/kg bolus IV + 0.01 mg/kg/h infusion IV during surgery and for 24 h postoperatively
Outcomes	Pain intensity (VAS) reported at 24 h postoperatively. PCA remifentanil consumption, reported at 0‐12 h, 12‐24 h and 0‐24 h postoperatively. AEs. Participant satisfaction with analgesia
Surgery type	Lower limb fracture operation
Group numbers after end of study (treatment/control)	150/50
Age of patient population (treatment/control)	49.6 ± 5.6 50.1 ± 6.3
Notes	No mention of sponsorship or funding
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation method not described
Allocation concealment (selection bias)	Unclear risk	Allocation concealment method not described in detail
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinded participants and personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded personnel
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Withdrawals not reported
Selective reporting (reporting bias)	Low risk	Predefined outcomes addressed
Size	Unclear risk	50 participants per treatment arm