Inhibition of the carotid chemoreceptor reflex by enflurane in chronically instrumented dogs.

The effect of the volatile inhalational anaesthetic enflurane (2 vol% and 4 vol%) on the cardiovascular response to carotid chemoreceptor stimulation (CCRS) was studied in 8 chronically instrumented dogs. Intracarotid injections of nicotine were used to evoke CCRS. Ventilation was held constant during the unanaesthetized state as well as the anaesthetized state. In the unanaesthetized state CCRS evoked an increase in iliac vascular resistance, and an increase in cardiac cycle length. Enflurane 2 vol% significantly attenuated the increases both in iliac vascular resistance as well as in cardiac cycle length. Enflurane 4 vol% abolished the response to CCRS.