EFFECTS OF ELTANOLONE ON CEREBRAL BLOOD-FLOW AND METABOLISM IN HEALTHY-VOLUNTEERS

Background: Eltanolone is a new steroid anesthetic agent that may prove to be useful in clinical practice. The aim of the present study was to evaluate the effects of eltanolone on cerebral blood flow (CBF) and metabolism in healthy volunteers. Methods: In a randomized cross-over study, eight subjects received intravenous eltanolone 0.6 mg/kg or its vehicle. CBF was measured with the intravenous xenon 133 technique before and 2 and 30 min after administration of eltanolone or vehicle. Cerebral metabolic rate for oxygen (CMR(O2)) was calculated as the product of the measured cerebral arteriovenous oxygen content difference and the blood flow. Results: CBF decreased from a baseline value of 64 +/- 4 (mean +/- SD) to 42 +/- 6 ml.100 g(-1).min(-1) at 2 min after administration of eltanolone and only 4% after vehicle. Cerebral oxygen consumption was 4.1 +/- 0.4 ml.100 g(-1).min(-1) at baseline and decreased to 2.7 +/- 0.6 at 2 min after eltanolone, whereas metabolism did not change significantly after administration of vehicle. At 30 min CBF and Cerebral metabolic rate for oxygen were 16 and 10% less than baseline values, respectively. Coupling between CBF and Cerebral metabolic rate for oxygen was preserved at all measurements. After administration of eltanolone a significant decrease in mean arterial blood pressure of 6 mmHg and a period of hypoventilation were observed. This did not occur after injection of vehicle. Conclusions: Eltanolone was shown to reduce cerebral oxygen consumption and blood flow in healthy volunteers. Coupling between metabolism and how was preserved.