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