POWER SPECTRAL-ANALYSIS OF THE ELECTROENCEPHALOGRAPHIC AND HEMODYNAMIC CORRELATES OF PROPOFOL ANESTHESIA IN THE RAT - INTRAVENOUS BOLUS ADMINISTRATION

Based on the tail-flick response to noxious thermal stimuli, we determ ined in the present study that the minimal effective antinociceptive d ose of propofol in adult, male Sprague-Dawley rats, given in an intrav enous bolus manner, was 10 mg/kg. Simultaneous power spectral analysis of the electroencephalographic (EEG) and systemic arterial pressure s ignals further revealed a concomitant transient suppression of the EEG activity, primarily in the theta and sigma bands, alongside minor hyp otensive and negative inotropic and chronotropic actions, but with mai ntained vasomotor tone. These alterations followed a time course that paralleled the plasma concentration of propofol in the arterial blood, as detected by high-performance liquid chromatography.