[Effects of dexmedetomidine on intracranial hemodynamics in severe head injured patients].

Dexmedetomidine, an alpha 2 adrenergic agonist, with distinctive characteristics when compared to traditional plans, namely: conscious sedation, sympatholysis and lack of respiratory depression, represents an attempt to improve the sedoanalgesia of critically ill patients. OBJECTIVE. To study dexmedetomidine's effect on intracranial hemodynamic and hemometabolic parameters in severe head injured patients. MATERIAL AND METHODS. Prospective study on the effect of Dexmedetomidine on twelve severe head injured patients (Glasgow Coma Scale score <or= 8) admitted to an intensive care unit, with intracranial pressure < 20 mmHg and O(2) saturation monitoring of blood from jugular bulb. The drug was perfused intravenously during 3 hours, in progressive doses (0.2, 0.4 and 0.7 ug/kg/h). All other sedo-analgesia medication had been previously withdrawn. RESULTS. No significant differences were found in intracranial pressure, mean arterial pressure and cerebral hemometabolic parameters after infusion of dexmedetomidine in relation to basal values. Cerebral perfusion pressure showed a trend to decrease during the drug infusion (marginal effect, p =.058). Cardiac frequency decreased significantly after the drug administration. CONCLUSIONS. At the doses utilized, dexmedetomidine was safe, and it was not associated with significant changes in intracranial hemodynamics, nor in cerebral hemometabolic parameters, in a group of severe head jnjured patients.