RESUMO
BACKGROUND: The application of skull pin holder elicits an adverse hemodynamic response that can be deleterious; there are many drugs that have been used to attenuate this response. We have conducted this study to evaluate the efficacy of intravenous (i.v.) dexmedetomidine on attenuation of hemodynamic responses to skull pin head holder application and to compare the effectiveness of two doses of i.v. dexmedetomidine (1 µg/kg and 0.5 µg/kg bolus). MATERIALS AND METHODS: Ninety American Society of Anesthesiologists physical Status I-III patients undergoing craniotomy were randomized into three groups of thirty each. After intubation, patients in Group A received 1 µg/kg of i.v. dexmedetomidine, Group B received 0.5 µg/kg of i.v. dexmedetomidine, whereas Group C received an equivalent quantity of normal saline. Hemodynamic parameters were monitored regularly after skull pin insertion. RESULTS: There was no significant difference in the monitored hemodynamic parameters among the three groups from baseline until intubation. Heart rate (HR) and mean arterial pressure (MAP) increased significantly at skull pin insertion and subsequent points in Group C, whereas the values decreased in Groups A and B (P < 0.05). Patients in Group A showed a higher and sustained attenuation of MAP. Patients in Group C had a higher incidence of tachycardia and hypertension requiring additional measures to attenuate the response. CONCLUSIONS: Dexmedetomidine in either dosage (1 µg/kg or 0.5 µg/kg) was effective in attenuating hemodynamic response to skull pin insertion. Dexmedetomidine in doses of 0.5 µg/kg was as effective in attenuating the HR and MAP response to skull pin insertion as compared to a dose of 1 µg/kg.
