Yazigi 2012.

Study characteristics
Methods	Randomised, double‐blind, placebo control
Participants	N = 60, about 52% women
Interventions	Pre‐incisional ketamine 0.1 mg/kg bolus IV + 0.05 mg/kg/h infusion IV during surgery and for 72 h postoperatively
Outcomes	Pain intensity (VAS) reported every 6 h for 3 days postoperatively. Cumulative analgesic requirement reported at 72 h. AEs
Surgery type	Thoracotomy
Group numbers after end of study (treatment/control)	30/30
Age of patient population (treatment/control)	57.3 ± 11.9 56.9 ± 12.5
Notes	No financial support or funding and no conflict of interest
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Random number table
Allocation concealment (selection bias)	Low risk	Central allocation by the hospital pharmacy (a third party). Study drugs were prepared in identical containers and marked with the name of the study and a consecutive number
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Blinded personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Blinded personnel
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Low risk	Predefined outcomes reported
Size	High risk	30 participants per treatment arm