HEMODYNAMIC-CHANGES DURING INDUCTION OF ANESTHESIA WITH ELTANOLONE AND PROPOFOL IN DOGS

The purpose of this study was to examine global and regional hemodynam ic changes during induction of anesthesia with eltanolone, a new short -acting steroid hypnotic, as compared to propofol, in chronically inst rumented dogs. The effects on cardiac performance were assessed in six animals. Renal and hepatic blood flows were examined in a separate st udy including five animals. Two doses of each drug were investigated: eltanolone 2.5 and 5 mg/kg and propofol 7.5 and 15 mg/kg. Left atrial filling pressures and cardiac output were not affected by either drug. Maximum rate of increase of left ventricular pressure decreased both with eltanolone (-28% and -40% from awake control for the 2.5 and 5 mg /kg doses, respectively) and with propofol (-19% and -30% from awake c ontrols with 7.5 and 15 mg/kg, respectively). In contrast to propofol, eltanolone preserved arterial blood pressure. Propofol lowered system ic vascular resistance (-21% and -39% with the low and high dose, resp ectively), and only slightly decreased left ventricular wall thickenin g fraction (-16% and -21%). Eltanolone did not affect systemic vascula r resistance but reduced the wall-thickening fraction dose-dependently (-28% and -61%). Propofol, but not eltanolone, induced moderate coron ary vasodilation. Hepatic arterial blood flow velocity decreased dose- dependently (-21% and -64%) during eltanolone anesthesia whereas, in c ontrast, it increased after propofol (+59% and +64%). Renal and portal venous blood flows remained essentially unaltered from awake conditio ns. Our data demonstrate that both propofol and eltanolone have cardio depressant properties but differ with regard to their effects on perip heral vascular tone. Systemic arterial vasodilation, as caused by prop ofol, may prove more favorable to overall cardiac performance. Liver b lood flow was also better preserved with propofol when compared to elt anolone.