1 Department of Anesthesiology, Faculty of Medicine, University of Thessaly, Biopolis, 41500, Larisa, Greece. Electronic address: thanoschalkias@yahoo.gr.
2 Department of Anesthesiology, VA Ann Arbor Healthcare System, 2215 Fuller Road, Ann Arbor, MI 48105, USA. Electronic address: mjarzebo@med.umich.edu.
3 Department of Anesthesiology, Critical Care Medicine, and Neurology, School of Medicine, Johns Hopkins University, Baltimore, MD 21287, USA. Electronic address: krosenb3@jhmi.edu.