1 Critical Care Department, General Hospital Papageorgiou, Thessaloniki, Greece;Critical Care Department, General Hospital G. Gennimatas, Thessaloniki, Greece;Department of Internal Medicine, Faculty of Medicine and Health Science, Ghent University, Ghent, Belgium, and Burns Trauma and Critical Care Research Centre Medical School, University of Queensland, Brisbane, Australia;Department of Hygiene and Epidemiology, Aristotle University of Thessaloniki, School of Medicine, Thessaloniki, Greece;Burns Trauma and Critical Care Research Centre Medical School, University of Queensland, Brisbane, Australia, and Critical Care Department, Attikon University Hospital, Medical School, University of Athens, Athens, Greece;Department of Hygiene and Epidemiology, Aristotle University of Thessaloniki, School of Medicine, Thessaloniki, Greece.