1. Emergency and Critical Care Medical Center, Fukushima Medical University Hospital, 1 Hikarigaoka, Fukushima 960-1295, Japan
2. Department of Anesthesiology, Ohta General Hospital Foundation, Ohta Nishinouchi Hospital, 2-5-20 Nishinouchi, Koriyama, Fukushima 963-8558, Japan
3. Department of Psychiatry, Hoshigaoka Hospital, 7 Kitasanten, Katahira, Koriyama, Fukushima 963-0211, Japan