Comparing the efficacy of Lidocaine versus Magnesium sulfate on pain associated with intravenous administration of Etomidate

Cardiovascular stability after induction of general anesthesia is the major advantage of Etomidate. The incidence of pain on injection is a side effect of using Etomidate.The purpose of this study is to compare the efficacy of Lidocaine versus Magnesium sulfate on pain associated with intravenous administration of Etomidate .
In this clinical trial study, 99 patients undergoing elective surgery aged 18-60 years were divided into 3 groups: group 1 (control) without medication, group 2 received 30 mg of lidocaine 1% and group 3 received 2.48 mMol of magnesium sulfate. After 3 minutes, 0.2mg/kg etomidate was injected. The severity of injection pain was immediately evaluated and recorded using the scale of Ambesh et al. Data were analyzed using ANOVA, Tukey and Kruskal-Wallis tests by SPSS software version 9.0.
The incidence of pain in group I (control), regardless of the intensity of pain, was 66/67%; in group II (lidocaine) 63/60% and in group III (magnesium sulfate) 45/45%, respectively. Pain in group II (receiving lidocaine) was lower than in group I (control) (p=0.030) and also lower in Group III (receiving magnesium sulfate) as compared to group I (control) (p=0.015). In terms of pain at the injection site after receiving lidocaine and magnesium sulfate, no significant differences were observed between groups II and III (p=0.325).
Patients receiving lidocaine and magnesium sulfate had less pain on injection with etomidate compared to the control group. But the pain in the magnesium sulfate group was lower in the lidocaine group.