1 Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Tokyo Medical and Dental University, 5-45, Yushima, 1-Chome, Bunkyo-ku, Tokyo, Japan. ysys@r5.dion.ne.jp.
2 Department of Anesthesiology and Critical Care Medicine, Faculty of Medicine, Tokyo Medical and Dental University, 5-45, Yushima, 1-Chome, Bunkyo-ku, Tokyo, Japan.
3 Department of Anesthesiology, Toride Kyodo General Hospital, Ibaraki, Japan.