1. Department of Anesthesiology and Intensive Care, Faculty of Medicine, University of Belgrade, Dr. Subotica 8, 11 000 Belgrade , Serbia
2. Department of Anesthesiology and Intensive Care, University Clinical Hospital Centre “Dr. Dragisa Misovic – Dedinje”, Heroja Milana Tepica 1, 11 000 Belgrade , Serbia
3. Department of Anesthesiology and Intensive Care, University Clinical Centre of Serbia, 11 000 Belgrade , Serbia
4. Intensive Care Unit, University Clinical Hospital Center Zemun, 11 000 Belgrade , Serbia
5. Department of Anesthesiology and Intensive Care, Medical Faculty, University of Defense, Veljka Lukica Kurjaka 1, 11 000 Belgrade , Serbia
6. Department of Anesthesiology and Intensive Care, Military Medical Academy, Crnotravska 17 , 11 000 Belgrade , Serbia