title: Comparison of effect of premixed lidocaine in propofol with or without ketorolac pretreatment with placebo on reducing pain on injection of propofol: A prospective, randomized, double-blind, placebo-controlled study in adult Korean surgical patients.
abstract: BACKGROUND
  Pain on injection of propofol is a common adverse event.
  
  
  OBJECTIVE
  The aim of this study was to investigate the effect of a combination of ketorolac pretreatment and premixed lidocaine in propofol compared with placebo on propofol injection pain.
  
  
  METHODS
  In this prospective, randomized, double-blind, placebo-controlled study, Korean patients scheduled for elective plastic surgery were randomized to 1 of 3 groups. Group A received 15 mg ketorolac in saline IV as pretreatment. Groups B and C received 3 mL saline IV as pretreatment. Sixty seconds after pretreatment, groups A and B received a mixture of lidocaine 1% in propofol 1% at a 1:10 ratio and group C received propofol 1% alone. Pain during propofol injection was assessed on a 4-point scale (0 = none, 1 = mild, 2 = moderate, 3 = severe).
  
  
  RESULTS
  Ninety patients (41 men, 49 vvomen; mean age, 41.7 years; mean weight, 63 kg) completed the study. The overall incidence of pain on propofol injection was significantly lower in groups A (16.7%) and B (36.7%) than in group C (83.3%; both, P < 0.001). There was no significant difference in the incidence of pain between groups A and B. However, the patients in group A reported a significantly lower incidence of moderate (0% vs 33.3%; P < 0.001) and severe pain (0% vs 20%; P = 0.024) compared with those in group C. There were no significant differences in the incidences of moderate and severe pain between the B and C groups.
  
  
  CONCLUSIONS
  In this Korean population, premixed lidocaine in propofol with or without ketorolac pretreatment was associated with significantly less pain when compared with placebo. The combination of ketorolac pretreatment and premixed lidocaine in propofol was more effective in decreasing the incidence of moderate or severe pain compared with placebo.
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Jinseok
authors.initials: J
authors.lastname: Yeo
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Younghoon
authors.initials: Y
authors.lastname: Jeon
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Youngsoo
authors.initials: Y
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Jaehyun
authors.initials: J
authors.lastname: Ha
authors.affiliation: Department of Anesthesiology and Pain Medicine, School of Medicine, Kyungpook National University, Daegu, Republic of Korea.
authors.forename: Woonyi
authors.initials: W
authors.lastname: Baek
keywords: complication; ketorolac; lidocaine; pain; propofol