From the Departments of Anesthesiology and General Intensive Care (A.M.M., C.G., M.Z., C.K.S.) and Surgery (T.B.), General Hospital, University of Vienna, Vienna, Austria; and the Ludwig-Boltzmann-Institute for Anesthesiology and Intensive Care (C.G., M.Z.), Vienna, Austria. Submitted for publication January 8, 2004. Accepted for publication April 20, 2004. Address for reprints: Anette-Marie Machata, MD, Department of Anesthesiology and General Intensive Care, General Hospital Vienna, University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria; email: [email protected].