1. From the Department of Anesthesiology, University of North Carolina School of Medicine, Chapel Hill, North Carolina (S.M.M., R.S.I., F.C.); the Department of Anesthesiology, University of Kentucky College of Medicine, Lexington, Kentucky (R.M.S.); Beth Israel Deaconess Medical Center, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Boston, Massachusetts, (J.D.M.