Comparing lidocaine with lidocaine/nitroglycerin in reducing pain of propofol injection in Anesthesia induction

Local pain due to propofol injection is a common side effect of propofol. Many methods have been introduced to reduce this pain. Combination of nitroglycerine and lidocaine is recomnded to reduce this pain. In this study, we aimed to compare the combination of nitroglycerine and lidocaine with lidocaine alone to reduce this pain of propofol injection in patients undergoing general anesthesia.In this double blind randomized clinical trial, 90 patients in three groups: 1- control group (placebo) 2- group(L) lidocaine 3- group LN: lidocaine + nitroglycerine. In control group, sterile water injected as placebo, in group l: lidocaine 2% with nitroglycerine 0.1 µ /kg was injected. Hemodynamic changes were measured during study. Pain and pain severity in these three groups were measured. Hemodynamic changes, systolic blood pressure and diastolic blood pressure heart rate and saturation in this study were unchanged. Pain in the control group was 96.7%, that was more than group L(56.7%) and more than group LN(6.7%) (p<0.001). Severity of pain in group LN was less than group L(P<0.001). Sever pain was not seen in group LN. Both Lidocaine and lidocaine +nitroglycerine reduced pain of propofol injection while combiniation of lidocaine and nitroglycerine has more efficacy and less pain so it can be used for reducing pain of propofol injection.