Efficacy of methylprednisolone and lignocaine on propofol injection pain: A randomised, double-blind, prospective study in adult cardiac surgical patients

BACKGROUND AND AIMS: Propofol (2, 6-di-isopropylphenol) used for the induction of anaesthesia often causes mild to severe pain or discomfort on injection. We designed this double-blind study to compare the efficacy of methylprednisolone and lignocaine in reducing the pain of propofol injection in patients scheduled for cardiac surgery. METHODS: A total of 165 adult patients, scheduled for elective cardiac surgery, were divided into three groups: saline (group S, n = 55), lignocaine 20 mg (Group L, n = 55) and methylprednisolone 125 mg diluted into 2 ml of distilled water (Group MP, n = 55). Drugs were administered after tourniquet application and occlusion was released after 1 min and 1/4(th) of the total dose of propofol (2 mg/kg) was administered at the rate of 0.5 ml/s. Pain on propofol injection was evaluated by four-point verbal rating scale. Statistical methods used included Student's t-test and Chi-square test/Fisher's exact test. RESULTS: The overall incidence of pain was 70.9% in the saline group, 30.9% in the lignocaine group and 36.4% in the methylprednisolone group. The intensity of pain was significantly less in patients receiving methylprednisolone and lignocaine than those receiving saline (P < 0.012). CONCLUSION: Pre-treatment with intravenous methylprednisolone was found to be as effective as lignocaine in reducing propofol injection-induced pain.