RESUMO
PURPOSE: Regardless of the positive attributes of propofol, it is frequently associated with pain on injection. We compared the efficacy of topical cold thermotherapy using an ice gel pack with intravenous lignocaine pre-treatment for reducing pain on propofol injection. METHODS: This single-blinded randomized controlled trial was conducted in 200 American Society of Anesthesiologists physical status I, II, and III patients scheduled for elective/emergency surgery under general anesthesia. The patients were randomized into two groups: the Thermotherapy group- receiving an ice gel pack proximal to the intravenous cannula for 1 min, or the Lignocaine group-receiving 0.5 mg/kg of lignocaine administered intravenously, with occlusion proximal to the site of the intravenous cannula for 30 s. The primary objective was to compare the overall incidence of pain after propofol injection. The secondary objectives included the incidence of discomfort on the application of an ice gel pack, comparison of dose of propofol needed for induction, and hemodynamic changes at induction, between the two groups. RESULTS: Fourteen patients in the lignocaine group and 15 patients in the thermotherapy group reported pain. The incidence of pain and the distribution of pain scores were comparable among groups (p = 1.00). Patients of the lignocaine group required significantly less amount of propofol for induction as compared to the thermotherapy group (p = 0.001). CONCLUSION: Topical thermotherapy using an ice gel pack was not found superior to lignocaine pre-treatment in alleviating pain on injection of propofol injection. However, topical cold therapy using an ice pack remains a non-pharmacological technique that is easily available, reproducible, and cost-effective. Further studies are required to prove its equivalence to lignocaine pre-treatment. TRIAL REGISTRATION: CTRI (CTRI/2021/04/032950).
