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

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.