1. Department of Anesthesia, Kyushukouseinenkin Hospital, Kitakyushu, Fukuoka, Japan
2. Department of Anesthesia, Wakamatsu Hospital of the University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan
3. Department of Anesthesia, Saiseikai Yahata General Hospital, Kitakyushu, Fukuoka, Japan