1. Division of Anesthesiology and Critical Care Medicine, Department of Surgery, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8504, Japan
2. Department of Anesthesiology, Yonago Medical Center, Yonago 683-0006, Japan
3. Department of Anesthesiology, Tottori Prefectural Central Hospital, Tottori 680-0901, Japan
4. Department of Anesthesiology, Ehime Prefectural Central Hospital, Matsuyama 790-0024, Japan