Asik 2003.

Methods	Randomized controlled trial
Participants	Age: N/A Gender: N/A Inclusion criteria: ASA I‐II, elective surgery Exclusion criteria: N/A Recruitment: 90 adult patients randomly assigned (30 in each group) Setting: Turkey
Interventions	Pretreatment with venous occlusion Patients were premedicated one hour before surgery with atropine 0.5 mg and meperidine 50 mg intramuscularly. Ninety patients scheduled for elective surgery under general anaesthesia were randomly allocated to one of three groups to receive pretreatment with venous occlusion, either metoprolol 2 mg, lidocaine 20 mg or saline 2 ml before any propofol was injected. Each patient was given one of these agents intravenously via a 20‐G cannula on the dorsum of the hand whilst the venous drainage was occluded manually, at the middle of the forearm, for 45 sec. After the occlusion was released, propofol 2.0 mg/kg to 2.5 mg/kg, at room temperature, was injected at 2 ml (20 mg) every 4 sec.
Outcomes	Pain intensity assessed on 3‐point scale 0 = no pain 1 = mild pain 2 = 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)	Unclear risk	N/A
Allocation concealment (selection bias)	Unclear risk	N/A
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	N/A
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	"Pain was assessed verbally and scored as none (0), mild (1) or severe (2). Every 4 sec during the injection of propofol, an independent investigator – blinded to the pretreatment solution used – asked the patients if they had any discomfort or pain in their arm."
Incomplete outcome data (attrition bias) All outcomes	Low risk	No withdrawals
Selective reporting (reporting bias)	Unclear risk	N/A
Other bias	Low risk	This study was conducted entirely from departmental resources. The study appears to be free of other sources of bias.