Comparing Three Doses of a Sedative Medicine to Control Heart Rate and Blood Pressure During Breathing Tube Placement in Planned Surgery.

INTERVENTION: Intervention1: Dexmedetomidine 0.75mcg/kg: Diluted with normal saline up to 10 ml, administered as IV infusion over 10 minutes before induction of anesthesia. Intervention2: Dexmedetomidine 1mcg/kg: Diluted with normal saline up to 10 ml, administered as IV infusion over 10 minutes before induction of anesthesia. Control Intervention1: Dexmedetomidine 0.5mcg/kg: Diluted with normal saline up to 10 ml, administered as IV infusion over 10 minutes before induction of anesthesia. CONDITION: Health Condition 1: R000‐ Tachycardia, unspecified PRIMARY OUTCOME: to find the optimal dose of Dexmedetomidine in attenuating The Hemodynamic changes during laryngoscopy and intubation in terms of systolic and diastolic blood pressure and mean arterial pressure.Timepoint: At Baseline before study drug infusion, then at O,2,5,10 minutes, immediately after induction, during intubation and at 1,2,3,4,5 and 10 minutes after intubation SECONDARY OUTCOME: Incidence of adverse effects such as bradycardia & hypotension, assessment of recovery time.Timepoint: Baseline, at 0,2,5 & 10 minutes during study drug infusion , immediately after induction, during intubation , at 1,2,3,4,5 & 10 minutes after intubation , & at extubation. INCLUSION CRITERIA: Patients of either gender aged 18 to 65 years with ASA physical status I or II, undergoing elective surgery under general anesthesia planned for oral endotracheal intubation, with BMI between 20 and 30 kg per square meter, willing to give informed consent.