Comparison of the effects of lidocaine pre-administration and local warming of the intravenous access site on propofol injection pain: Randomized, double-blind controlled trial

Background: Lidocaine reduces pain that occurs upon the intravenous injection of propofol. But, there are few non-pharmacological nursing interventions to reduce propofol injection pain. Objective: To compare the effects of lidocaine pre-administration and local warming of the intravenous access site on propofol injection pain. Design: Prospective, double-blind, randomized controlled trial. Setting: The 555 bed, non-teaching National Cancer Center in Kyunggido, South Korea. Participants: A total of 96 patients who underwent thyroidectomy under total intravenous general anesthesia with propofol were randomly allocated to the control, lidocaine pre administration (LA) or local warming (LW) group. Methods: All three groups received 2% propofol with an effect-site target at 3 pg/mL for induction dose. The control group received 2% propofol with no intervention. The lidocaine pre-administration group received 2% propofol 30 s after 1% lidocaine 30 mg. The local warming group received 2% propofol after warming of the intravenous access site for 1 min using 43 degrees C forced air. Propofol injection pain was assessed by four-point verbal categorial scoring (VCS), numerical rating scale (NRS) and surgical pleth index (SPI). Results: Pain VCS of the LA group (mean SD, 1.11 +/- 0.45) was significantly reduced (U=-3.92, p < .001) compared to the control group (mean SD, 1.71 +/- 0.74). Pain VCS of the LW group (mean SD, 0.76 +/- 0.44) was significantly reduced (U =-5.17, p < .001) compared to the control group (mean SD, 1.71 +/- 0.74). Pain VCS of the LW group was significantly reduced compared to the LA group (U=-3.33, p =.001]. Pain NRS of the LA group (mean SD, 431 +/- 2.32) was significantly reduced (mean difference, 1.82; 95% CI, 0.63-3.00; p =.003) compared to the control group (mean SD, 6.13 +/- 2.39). Pain NRS of the LW group (mean SD, 3.06 +/- 2.37) was significantly reduced (mean difference, 3.07; 95% CI, 1.63-4.51; p <.009) compared to the control group. There were significant differences in pain NRS between the LA group and the LW group (mean difference, 1.25; 95% CI, 0.09-2.42; p =.035). SPI of the LA group (mean SD, 64.1 +/- 16.3) was significantly reduced (mean difference control versus LA, 836; 95% CI, 1.64-15.1; p =.016) compared to the control group (mean SD, 72.5 9.56). SPI of the LW group (mean SD, 55.0 +/- 16.2) was significantly reduced (mean difference control versus LW, 17.4; 95% CI, 10.8-24.0; p <.001) compared to the control group. There was a significant difference in SPI between the LA group and LW group (mean difference, 9.06; 95% CI, 1.02-17.1; p =.028). Conclusion: Local warming of the intravenous access site by 43 degrees C forced air for 1 min is slightly more effective in reducing propofol injection pain compared to lidocaine pre administration. (C) 2016 Elsevier Ltd. All rights reserved.