1. Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, California, USA
2. Department of Medical Education, University of Illinois at Chicago College of Medicine, Chicago, Illinois, USA
3. Department of Anesthesiology, University of Southern California, Los Angeles, California
4. Department of Anesthesiology, University of California Irvine, Irvine, California, USA
5. UCLA-Harbor Medical Center, Lost Angeles, California, USA
6. Department of Anesthesiology, Duke University School of Medicine, Raleigh, North Carolina, USA