In D group, patients will be given intranasal dexmedetomidine 2mcg/kg upto maximum dose of 100mcg prepared from 100mcg/ml parenteral preparation (Hospira R). The drug will be administered using a intranasal mucosal administration device (LMA MAD NasalTM). Atomized nasal medications offer rapid absorption across mucosal membranes to the blood stream avoiding first-pass metabolism.