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| Cerebral blood flow and
somatosensory evoked potentials with several xenon
concentrations in primates Wlodzimierz Lewelt, Douglas DeWitt, Lauraine Stewart & Richard Keenan The effect of several stable xenon (XeS) concentrations on cerebral blood flow (CBF), cerebral metabolic rate for oxygen (CRMO2), and somatosensory evoked potentials (SEP) was studied in primates. Six baboons were anesthetized with ketamine (11 mg/kg i.m.), intubated, paralyzed with pancuronium, and mechanically ventilated. CBF was determined using radioactive microspheres. CMRO2 was calculated from CBF and arteriovenous oxygen difference. The SEP were recorded from parietal electrodes in response to contralateral median nerve stimulation. All measurements were conducted during ventilation with 0%, 25%, 35%, 50%, and 60% XeS mixed with oxygen. Data were statistically analyzed using Tukey’s studentized range test. CBF was not significantly affected by inhalation of XeS in concentrations up to 50%. Only the highest concentration of XeS (60%) caused a statistically significant increase in CBF (18% increase in CBF if compared with 0% XeS value; p < 0.05). Evoked activity of the brain was depressed progressively by increasing concentrations of XeS, with amplitude being more affected than latency. Cerebral metabolism did not change significantly during the study. Keywords: Cerebral blood flow, cerebral oxygen metabolism, evoked potentials, microspheres, monkeys, xenon Applied Cardiopulmonary Pathophysiology 7: 209-214, 1998 Wlodzimier Lewelt, M.D. |
| PABST SCIENCE PUBLISHERS Lengerich, Berlin, Düsseldorf, Leipzig, Riga, Scottsdale AZ (USA), Wien, Zagreb |
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