The patients will be randomly allocated to one of the two groups separated by method of dexmedetomidine administration. The pre-induction and the infusion dose of dexmedetomidine will be 1-µ/kg over 10 minutes and 0.5-µ/kg/hour, respectively. Dexmedetomidine infusion will be stopped in case of acute haemodynamic suppression (>20% pre-induction baseline) or acute blood loss (>200-ml) at any point of time and it will be recorded as an event. It will be restarted upon normalcy of haemodynamics is achieved and also full surgical hemostasis is ensured.