EFFECTS OF BASAL ANESTHESIA ON THE RESPONSE OF SYMPATHETIC NERVOUS ACTIVITY AND BAROSTATIC REFLEXES TO A SUBSEQUENT ADMINISTRATION OF HALOTHANE

¹ Department of Anesthesia, University of Pennsylvania, Philadelphia, Pennsylvania

Chloralose is a basal anesthetic under which responses (including barostatic reflexes) are well preserved and for this reason it is often employed in animal studies. We found by chance that in the cat the response to an inhalational anesthetic, halothane, was profoundly modified by the previous administration of chloralose. This report documents and extends our initial findings. The present study illustrates the difficulty in interpreting animal studies where the drugs administered interact with the basal anesthetic in an unpredictable manner, and in evaluating the extent to which sympathetic depression can be considered the cause of cardiovascular changes.