Effects of sevoflurane on central nervous system electrical activity in cats.
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.
Osawa
M
M
Department of Anesthesia, Kyoto University Hospital, Japan.
Shingu
K
K
Murakawa
M
M
Adachi
T
T
Kurata
J
J
Seo
N
N
Murayama
T
T
Nakao
S
S
Mori
K
K
D000777:Anesthetics / Q000494:pharmacology*; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000502:physiology; D002415:Cats; D004569:Electroencephalography / Q000187:drug effects; D004594:Electrophysiology; D004987:Ethers / Q000494:pharmacology*; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects; D005260:Female; D008297:Male; D008738:Methyl Ethers; D012154:Reticular Formation / Q000187:drug effects / Q000502:physiology; D000077149:Sevoflurane
D000777:Anesthetics; D004987:Ethers; D008738:Methyl Ethers; D000077149:Sevoflurane