1. From the Department of Anesthesiology, Duke University School of Medicine, Durham, North Carolina (E.D.K.); Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (M.J.A.); Anesthesiology Service, Veterans Affairs Palo Alto Health Care System, Palo Alto, California (J.D.C.), and Department of Anesthesiology, Stanford University School of Medicine, Sta