[The effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia].
BACKGROUND
The purpose of this study is to investigate the effects of hyperventilation upon spinal dorsal horn neuronal single-unit activities under nitrous oxide anesthesia.


METHODS
Eight decerebrated spinal cats with laminectomy were maintained with oxygen and pancuronium bromide. Following the control period of normocapnia, 50% nitrous oxide was administered for 30 minutes after a hypocapnia period of 20-25 mmHg for 20 minutes. The recoveries of activities followed with normocapnia and pure oxygen administration. The changes of spontaneous and evoked activities by the pinching were investigated every 5 minutes after control study.


RESULTS
Inhalation of 50% nitrous oxide suppressed the WDR neuronal activities and with hyperventilation the suppressions significantly increased.


CONCLUSIONS
These results were compatible with clinical reports on the effectiveness of hyperventilation as a maintenance method under N2O anesthesia.
Ide
Yasuo
Y
Department of Anesthesiology, Toho University Sakura Hospital, Sakura.
Tagami
Megumu
M
Sumida
Toshinobu
T
Hanaoka
Kazuo
K
D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000494:pharmacology*; D000818:Animals; D002415:Cats; D005260:Female; D006985:Hyperventilation / Q000503:physiopathology*; D008297:Male; D009609:Nitrous Oxide / Q000494:pharmacology*; D020671:Posterior Horn Cells / Q000503:physiopathology*
D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide