1 Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Boston, Massachusetts.
2 Department of Anesthesia and Critical Care, University of Chicago, Chicago, Illinois.
3 Department of Anesthesiology, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire, Yvon.F.Bryan@hitchcock.org.