Smith 1996.

Methods	Randomized controlled trial
Participants	Age (years, mean ± SD): Group 1 = 37.6 ± 12.6, Group 2 = 34.2 ± 15.5, Group 3 35.4 ± 11.8 Gender (M:F): Group 1 = 7:28, Group 2 = 2:30, Group 3 = 9:25 Inclusion criteria: aged 16 years and older, ASA I‐II, day case surgery Exclusion criteria: patients taking sedative or analgesic medication Recruitment: 101 adult patients randomly assigned Setting: United Kingdom
Interventions	Pretreatment alone Group 1 (n = 35) received ketorolac 10 mg in 2 ml of NSS pretreatment Group 2 (n = 32) received 1% lidocaine 2 ml (20 mg) pretreatment Group 3 (n = 34) received 2 ml of NSS followed by propofol 2.5 mg/kg
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 (thrombophlebitis within seven days postoperatively by self‐assessment questionnaire. The overall return rate of questionnaire was 80%. The incidence of thrombophlebitis was 4/30 patients in ketorolac group, 9/22 in lidocaine pretreatment group, and 4/29 in saline group. However, there was no significant differences between the groups) 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)	Unclear risk	N/A
Allocation concealment (selection bias)	Unclear risk	N/A
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The patient and observer were unaware of which drug was given." "All drugs were drawn up and given by an anaesthetist who was not part of the study."
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