Comparative effects of intravenous esmolol and lidocaine on bispectral index during propofol-fentanyl induction in patients scheduled for elective surgeries under general anaesthesia

INTRODUCTION: Laryngoscopy and endotracheal intubation at induction of anaesthesia have been associated with awareness and haemodynamic fluctuations. Agents that can mitigate these effects should create better anaesthetic conditions. This study aimed to compare the effects of intravenous esmolol and lidocaine on the bispectral index (BIS) and haemodynamic responses during induction of general anaesthesia with propofol/fentanyl in adult patients scheduled for elective surgical procedures. METHODS: This was a prospective randomized controlled study in ninety patients aged 18-65 years who were randomized into three groups to receive either IV esmolol 0.5 mg/kg, IV lidocaine 1.5 mg/kg or normal saline prior to induction of general anaesthesia. RESULTS: The esmolol group had a significantly shorter induction time (p<0.0001) and a lower dose of propofol consumed (p<0.0001) than the lidocaine group. The mean pulse rate was significantly lower at the 1st min to 4th min post-intubation in esmolol and lidocaine groups compared to the control group (p values; 1 min= 0.005, 2 min= 0.008, 3 min= 0.023, 4 min= 0.018). There was a significant difference in the systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) in the three groups at 2 min post-intubation. CONCLUSION: Pre-induction intravenous esmolol 0.5 mg/kg was more effective than intravenous lidocaine 1.5 mg/kg in reducing the induction dose of propofol and the induction time. Esmolol also prevented increases in BIS better than lidocaine following endotracheal intubation but both agents were equally effective in attenuating the haemodynamic changes associated with laryngoscopy and endotracheal intubation.