Borazan 2010.

Methods	Double‐blind randomized controlled trial
Participants	Age (years, mean ± SD): Group P0.5 = 45.18 ± 12.44, Group P1 = 45.24 ± 14.36, Group P2 = 43.54 ± 15.01, Group L = 41.28 ± 14.12, Group C = 44.06 ± 13.62 Gender (M:F): Group P0.5 = 26:24, Group P1 = 33:17, Group P2 = 31:19, Group L = 36:14, Group C = 26:24 Inclusion criteria: age 20 years to 60 years old, ASA I‐II, elective surgery Exclusion criteria: patients who experienced difficulty in communication, those with body weight exceeding 75 kg, those who had cardiac, renal and hepatic failure, those who were taking antianxiety drugs for psychiatric or neurological disorders and those who had a known allergy to the study drugs Recruitment: 250 adult patients randomly assigned into five groups (50 in each group) Setting: Turkey
Interventions	Pretreatment with venous occlusion Group P0.5, group P1 and group P2 received 0.5, 1 and 2 mg/kg paracetamol respectively Group L: received 0.5 mg/kg lidocaine Group C: received isotonic saline pretreatment in the dorsum of the hand A rubber tourniquet was placed on the forearm for 1 min to produce a venous occlusion; the patients were pretreated over a period of 15 seconds followed by propofol 1 min later
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 Adverse effects Outcomes sought but not reported 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	"A computer‐conducted randomization in which the code was sealed until the arrival of the patient in the operating room."
Allocation concealment (selection bias)	Low risk	"A computer‐conducted randomization in which the code was sealed until the arrival of the patient in the operating room."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The drugs were prepared by one of the investigators, with both the patient and an independent observer (a trainee anaesthesiologist)."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	"The drugs were prepared by one of the investigators, with both the patient and an independent observer (a trainee anaesthesiologist)."
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.