1 Department of Emergency and Critical Care Medicine, Hitachi General Hospital, Hitachi, Ibaraki, Japan. Electronic address: utmed18@live.jp.
2 Department of Emergency and Critical Care Medicine, Hitachi General Hospital, Hitachi, Ibaraki, Japan; Department of Emergency and Critical Care Medicine, University Hospital, The University of Tokyo, Bunkyo, Tokyo, Japan.
3 Department of Emergency and Critical Care Medicine, Hitachi General Hospital, Hitachi, Ibaraki, Japan; Department of Emergency and Critical Care Medicine, University Hospital, The University of Tokyo, Bunkyo, Tokyo, Japan; Department of Emergency Medicine, JR General Hospital, Sbuya-ku, Tokyo, Japan.