Byon 2014.

Methods	Double‐blind randomized controlled trial
Participants	Age 20 years to 65 years, ASA I or II, injected with propofol for general anaesthesia Exclusion criteria: ischaemic heart diseases, neurologic problems, pregnancy, breast‐feeding women, administration of analgesics within 24 hours before surgery, allergic to propofol or its contents (soy‐bean oil, MCT, glycerol, egg lecithin, and sodium oleate), and allergic to lidocaine. Recruitment: 234 participants were randomly assigned (117 participants in each group) Setting: Korea
Interventions	Pretreatment alone Admixture The pretreatment group was injected with a 40 mg solution of 2% lidocaine at the distal‐most part of the intravenous line, flushed with 3 ml of normal saline. One minute later, propofol 2 mg/kg with 2 ml of normal saline solution was injected The premixed group was pretreated with a tourniquet with 2 ml of normal saline, then flushed with 3 ml of normal saline. Then one minute later, propofol 2 mg/kg with a 40 mg solution of 2% lidocaine was injected All of the agents were injected at the same rate of 1 ml/sec, as the drug infusion rate may affect the incidence of propofol injection pain
Outcomes	Pain intensity assessed on 3‐point scale No pain Minor pain criteria included moaning and frowning Major pain criteria included verbal expressions of pain and movement of hand with a look of withdrawing from pain Other outcomes: pain incidence, adverse effects
Notes	There was no control group