Affiliation: | (1) Department of Anesthesiology, Takikawa Municipal Hospital, 2-2-34, 073 Ohmachi, Takikawa, Japan;(2) Department of Anesthesiology, Otaru City General Hospital, 1-2-1 Wakamatsu, 047 Otaru, Japan;(3) Department of Neurosurgery, Municipal Second Hospital of Otaru, 3-11-1, Otaru 047 Nagabashi, Japan |