1. Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan 333, Taiwan
2. College of Medicine, Chang Gung University, Taoyuan 333, Taiwan
3. Department of Surgery and Center for Surgical Research, University of Alabama at Birmingham, Birmingham, AL 35294, USA
4. Department of Surgery, Loyola University Chicago Health Sciences Campus, Maywood, IL 60153, USA
5. Department of Anesthesiology, Chi Mei Medical Center, Tainan 710, Taiwan
6. Department of Anesthesiology, University of Hong Kong, Pokfulam, Hong Kong