Minogue 2005.

Methods	Randomized controlled trial
Participants	Age (years, mean ± SD): Benzyl alcohol group (BA) = 44 ± 16, Placebo group (PL) = 41 ±12, Lidocaine group (LI) = 41 ± 12 Gender (M:F): BA group = 8:31, PL group = 18:21, LI group = 7:35 Inclusion criteria: ASA I‐II, elective surgery Exclusion criteria: N/A Recruitment: 120 adult patients randomly assigned Setting: Canada
Interventions	Admixture The benzyl alcohol (BA; n = 39) group received 10 ml of bacteriostatic saline followed by 5 ml (50 mg) of propofol. The lidocaine (LI; n = 42) group, 1 ml of 2% lidocaine (20 mg) was premixed with 19 ml of propofol (190 mg). Ten ml of preservative‐free normal saline was then administered followed by 5 ml of the propofol and lidocaine mixture The placebo (PL; n = 39) group received 10 ml of preservative‐free normal saline followed by 5 ml of propofol
Outcomes	Pain intensity assessed on 4‐point scale 0 = no pain 1 = mild pain 2 = moderate pain 3 = severe pain Outcomes reported and used Incidence of high‐intensity pain Incidence of pain Outcomes sought but not reported Adverse effects Patient satisfaction
Notes	Period of the study: dates not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Using a randomly‐generated computer assignment
Allocation concealment (selection bias)	Unclear risk	N/A
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The agents were prepared by the investigator and given to the attending anaesthesiologist who was blinded as to the contents."
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	N/A
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Unclear risk	N/A
Other bias	Low risk	The study appears to be free of other sources of bias