1 Department of Anesthesiology, Osaka Metropolitan University Graduate School of Medicine, 1-5-7 Asahimachi, Abenoku, Osaka City, Osaka, 545-8586, Japan.
2 Department of Anesthesiology, Osaka Metropolitan University Graduate School of Medicine, 1-5-7 Asahimachi, Abenoku, Osaka City, Osaka, 545-8586, Japan. suehirokoichi@yahoo.co.jp.