1. Department of Anesthesiology, Shuang Ho Hospital, Taipei Medical University, New Taipei City 10361, Taiwan
2. Department of Anesthesiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei 10031, Taiwan
3. Department of Anesthesiology, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei 10002, Taiwan
4. Department of Anesthesiology, Washington University School of Medicine, St. Louis, MO 63110, USA
5. Department of Anesthesiology, National Taiwan University Hospital Hsin-Chu Branch, Hsin-Chu City 30059, Taiwan