1. Department of Anesthesiology, China Medical University Hospital and China Medical University, Taichung 404327, Taiwan
2. Department of Anesthesiology, Kaohsiung Chang Gung Memorial and College of Medicine, Chang Gung University, Kaohsiung 833401, Taiwan
3. Department of Anesthesiology, Linko Chang Gung Memorial Hospital and Graduate Institute of Clinical Medical Sciences, College of Medicine, Chang Gung University, Taoyuan 333423, Taiwan