This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Takayama, R. Articles by Mori, H. Search for Related Content PubMed PubMed Citation Articles by Takayama, R. Articles by Mori, H. Related Collections Neuroanesthesia Anesthetic Techniques

---

NEUROSURGICAL ANESTHESIA

Selective Brain Hypothermia Suppresses Noxious-Evoked Movement in Canines

Ryukichi Takayama, MD^*, Rumiko Uda, MD^*, Naofumi Isono, MD, Motomasa Furuse, MD, Tomio Ohta, MD, Toshihiko Kuroiwa, MD, and Hidemaro Mori, MD^*

Department of *Anesthesiology and Neurosurgery, Osaka Medical College, Japan

Address correspondence and reprint requests to Ryukichi Takayama, MD, Department of Anesthesiology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki, Osaka 569-8686, Japan. Address e-mail to ane030{at}poh.osaka-med.ac.jp.

Systemic hypothermia suppresses noxious-evoked movement, but its main site of action is unknown. We examined the effect of hypothermia in the brain on noxious-evoked movement by selectively cooling the brain. Sixteen beagles were randomly divided into two groups and anesthetized with isoflurane/oxygen. After being deeply anesthetized, the dogs’ lungs were artificially ventilated, and several major vessels were cannulated for perfusion and monitoring. Cold lactate Ringer’s solution was infused into the right vertebral artery to cool the brain while maintaining the trunk temperature relatively warmer. When the brain temperature decreased to 20°C or 25°C, isoflurane administration was discontinued; the trunk temperatures at this stage were approximately 34.7°C and 34.6°C, respectively. After the end-tidal isoflurane concentration reached 0%, the base of the tail was stimulated with an electric current through 2 25-gauge needles. None of the dogs reacted to tail stimulation when the brain temperature was at 20°C, whereas 7 of 8 reacted at 25°C. These results indicate that selective brain hypothermia (20°C) results in suppressing noxious-evoked movement in canines.