THIOPENTAL INDUCED CEREBRAL PROTECTION DURING ISCHEMIA IN GERBILS

Temporary interruption or reduction of cerebral blood flow during cere brovascular surgery may rapidly result in ischemia or cerebral infarct ion. Thiopental has been shown to have cerebroprotective effects. Howe ver, the cerebroprotective dose of thiopental causes burst suppression of the EEG, thus this parameter cannot be used continuously for the d etection of metabolic changes in the brain during thiopental anaesthes ia. This study was performed in order to examine whether the multipara metric assembly (MPA), which measures energy metabolism CBF and mitoch ondrial (NADH) as well as extracellular ion concentrations (K+), can s hed Light on the mechanism of the cerebroprotective effects of thiopen tal. The MPA was placed on the brain of Mongolian gerbils and burst su ppression of the ECoG was induced by thiopental. Cerebral ischemia was induced by occlusion of carotid arteries after burst suppression. Bur st suppression of the ECoG was accompanied by a significant decrease i n cerebral blood flow. In animals that received thiopental prior to is chemia, NADH increased to a lesser degree and extracellular potassium ion concentration increased to a lesser. degree than in the control an imals, indicating that thiopental affords protection of the brain unde r ischemic conditions due to improved energy metabolism. This study al so demonstrates that the MPA can monitor changes occurring in the cere bral cortex even after the ECoG can no longer be used. Those findings have a significant value in the development of a new clinical monitori ng device. (C) 1998 Elsevier Science B.V.