Background: The skull pin holder placement in neurosurgery is the strong stimuli that produced the intense sympathetic response. Dexmedeto­midine is one of many drugs that have been used to attenuate this response. We evaluate the effective intravenous dose of dexmedetomidine 0.5 μg/kg and 0.75 μg/kg infusion that can blunt hemodynamic response.

Methods: This study is a prospective, randomized controlled double-blinded study. A total of one hundred and twenty patients were selected and randomized into three groups of forty patients each: group 1 received an infusion of dexme­detomidine 0.5 μg/kg, group 2 received an infusion of dexmedetomidine 0.75 μg/kg, and group 3 received an equivalent quantity of normal saline. Hemodynamic parameters were monitored

 regularly of skull pin holder placement.

Result: There was no significant difference in the monitored hemodynamic parameters among the three groups from baseline until intubation time. Heart rate (HR) and mean arterial pressure (MAP) increased significantly in group 3, whereas the values decreased in group 1 and 2 (P<0.001). Group 2 showed a higher and sustained attenuation of HR and MAP. Group 3 had a higher incidence of tachycardia and hypertension that need medication to treat the response.

Conclusion: Dexmedetomidine in both doses (0.5 μg/kg and 0.75 μg/kg infusion) was effective in attenuating hemodynamic response to skull pin holder placement.