Children will receive a nebulized dexmedetomidine 2 mic/ kg diluted in 3 ml of 0.9% saline 1 h before induction of anaesthesia.

Children will receive intravenous (IV) dexmedetomidine 1mic/kg diluted in 10 ml of 0.9% saline over 10 minutes after anesthesia induction.

Children will receive a nebulized dexmedetomidine 2 mic/ kg diluted in 3 ml of 0.9% saline 1 h before induction of anaesthesia by standard hospital jet nebulizer via a mouthpiece with a continuous flow of 100% oxygen at 6 L /min for 10-15 min. Treatment will be stopped when the nebulizer began to sputter. At end of nebulizer administration, they will be observed for 30 min before induction of general anaesthesia. then the children will be transferred to the operation room and will receive intravenous (IV) normal saline 0.9% in 10 ml volume over 10 minutes after anesthesia induction.

Paediatric Anaesthesia Emergence Delirium (PAED) scale will be used to evaluate emergence agitation upon admission to the PACU (0 min, baseline) and at 5, 10, 20, 30, 45, and 60 min until discharge from the PACU. The highest EA scores observed during this period will be recorded.

PAED score ≥ 10 will be considered to be a diagnostic endpoint for the development of agitation.

Postoperative pain will be recorded using FLACC scale at 5, 10, 20, 30, 45, and 60 min until discharge from the PACU.

Emergence agitation onset time was defined as the interval from the extubation to the occurrence.