1. Department of Anesthesiology, Quality and Safety, Boston Medical Center, Boston, Massachusetts
2. Department of Anesthesiology, Chobanian and Avedisian School of Medicine, Boston, Massachusetts
3. Department of Surgery, John A. Burns School of Medicine, Honolulu, Hawaii
4. Faculty, Ariadne Laboratories, Boston, Massachusetts
5. Department of Anesthesiology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
6. Department of Anesthesia, Harvard Medical School, Boston, Massachusetts