Comparison of labetalol versus dexmedetomidine to assess the haemodynamic responses to laryngoscopy and intubation during induction of general anaesthesia – a prospective, randomized, controlled study

Background and aims: During general anaesthesia, maneuver of laryngoscopy and tracheal intubation is accompanied by varying degree of sympathetic stimulation. This may prove detrimental in patients with compromised cardiac and cerebrovascular reserve and hence many approaches have been tried to prevent the potentially adverse circulatory responses. In the present study, we compared dexmedetomidine with labetalol to assess and evaluate the haemodynamic responses to laryngoscopy and endotracheal intubation during induction of general anaesthesia and during extubation. Material and methods: This study was carried out in ninety patients who were posted for various surgeries requiring general anaesthesia with orotracheal intubation. They were allocated into three groups. Group D patients received 0.5mcg/kg dexmedetomidine, diluted to 5ml of 0.9% normal saline, group L received 0.25mg/kg labetalol diluted to 5 ml normal saline and group C received 5ml 0.9%normal saline. All study drugs were administered over 5 minutes followed by induction with IV Propofol 2mg/kg and suxamethonium 1.5 mg/kg. Maintenance of anaesthesia was done with 100% oxygen, sevoflurane and IV Atracurium. Haemodynamic monitoring of systolic and diastolic blood pressure, heart rate(HR), mean arterial pressure(MAP) were done. Calculation of rate pressure product( RPP) were done and all parameters were compared at intubation(I0), 1(I1), 3(I3), 5(I5), 10(I10) and 15(I15) minutes postintubation, intraoperatively and at extubation. Results: Group D and group L showed statistically significant fall in HR,SBP, DBP, MAP RPP at induction, at intubation(I0), I1, I3, I5, I10, I15 than group C(p