A comparative study of attenuation of propofol-induced pain by lignocaine, ondansetron, and ramosetron

BACKGROUND AND AIMS: Propofol is widely used for induction of anaesthesia, although the pain during its injection remains a concern for all anaesthesiologists. A number of techniques have been adopted to minimise propofol-induced pain. Various 5-hydroxytryptamine-3 antagonists have shown to reduce propofol-induced pain. Hence, this placebo-controlled study was conducted to compare the efficacy of ondansetron, ramosetron and lignocaine in terms of attenuation of propofol-induced pain during induction of anaesthesia. METHODS: Hundred and fifty adult patients, aged 18–60 years, posted for various elective surgical procedures under general anaesthesia were randomly assigned to three groups of 50 each. Group R received 0.3 mg of ramosetron, Group L received 0.5 mg/kg of 2% lignocaine and Group O received 4 mg of ondansetron. After intravenous (IV) pre-treatment of study drug, manual occlusion of venous drainage was done at mid-arm with the help of an assistant for 1 min. This was followed by administration of propofol (1%) after release of venous occlusion. Pain was assessed with a four-point scale. Unpaired Student's t-test and Chi-square test/Fisher's exact test were used to analyse results. RESULTS: The overall incidence and intensity of pain were significantly less in Groups L and R compared to Group O (P ≤ 0.001). The incidence of mild to moderate pain in Groups O, R and L was 56%, 26% and 20%, respectively. The incidence of score ‘0’ (no pain) was significantly higher in Group L (76%) and Group R (72%) than Group O (34%) (P < 0.001). CONCLUSION: Pre-treatment with IV ramosetron 0.3 mg is equally effective as 0.5 mg/kg of 2% lignocaine in preventing propofol-induced pain and both were better than ondansetron.