Effects of Sevoflurane on Central Nervous System Electrical Activity in Cats

Abstract

We analyzed the effect of a new volatile anesthetic, sevoflurane (2%-5% in oxygen) on the electroencephalogram (EEG) of the neocortex, amygdala, and hippocampus, cortical somatosensory evoked potential (SEP), and brainstem reticular multiunit activity (R-MUA) in cats. Sevoflurane suppressed the background activity of the neocortex more than the amygdala and hippocampus. With increasing concentration of sevoflurane, the cortical EEG progressed from high-amplitude slow waves to a suppression-burst pattern, which was followed by an isoelectric pattern and then spikes with isoelectricity. The amplitude of the SEP was augmented and the R-MUA was suppressed by sevoflurane in a dose-related manner. Repetitive peripheral electrical stimulation induced generalized seizures at 5% sevoflurane in 2 of 13 cats. These results suggest that sevoflurane suppresses the background central nervous system electrical activities in a dose-related manner, leaving the reactive capabilities facilitated at deep anesthesia.

Anticonvulsant effects of sevoflurane on amygdaloid kindling and bicuculline-induced seizures in cats: comparison with isoflurane and halothane

“…These findings indicate that sevoflurane has a proconvulsant effect, which partially masks the anticonvulsant effects. This result is consistent with our previous report of the proconvulsant effects of large concentrations of sevoflurane in cats [4]. Isoflurane also induced spontaneous sporadic spikes on EEGs in cats [18,20], but it did not induce photic stimulationinduced spikes on EEG nor did it augment the photic stimulation-evoked potential in the visual cortex [20].…”

“…Sevoflurane is widely used, and has neurophysiological properties similar to those of enflurane. Seizure shown on electroencephalograms (EEGs) can be induced by peripheral somatic stimulation performed in cats under sevoflurane anesthesia [4]. Further, there are a few case reports of the intraoperative occurrence of seizure under sevoflurane anesthesia [5,6].…”

Clonidine premedication for sevoflurane anesthesia in upper abdominal surgery

“…We previously studied the action of sevoflurane on the somatosensory evoked potential and spontaneous brain activity in the cat [6]. Although sevoflurane depressed spontaneous brain activity, it augmented the somatosensory evoked potential, suggesting a weak suppressive action of sevoflurane on CNS response to peripheral stimulation while tonic CNS activity was suppressed.…”

Comparative Study of Sevoflurane and Isoflurane Anesthesia for the Long-term Safety Evaluation of Visual Prosthesis with Rabbits

“…(13)(14)(15) SF anesthesia has been used for in vivo evoked potential measurements, but not yet in rabbits. (16,17) There have been some studies of evoked potentials, such as VEP in IF anesthesia targeting rabbits; (18) however, there are no reports on rabbit-targeted VEP and EEP studies using SF anesthesia. The purpose of this study was to investigate whether SF anesthesia may be used as an alternative to IF anesthesia in evoked potential measurement for the assessment of the long-term safety evaluation of visual prostheses.…”