Comparison of Dexmedetomidine and Fentanyl to Prevent Hemodynamic Response to Skull Pins Application

Dexmedetomidine 1 µg/kg diluted to 20 ml with 0.9% normal saline was administration. If adverse events were occurred, the patient will receive rescue drugs.

Fentanyl 1 µg/kg diluted to 2 ml with 0.9% normal saline was administration. If adverse events were occurred, the patient will receive rescue drugs.

0.9% normal saline was use to dilute the study drugs

Skull pins were use to stabilized the patent' s head during surgery