1. Medical Department, Ferrer, 08029 Barcelona, Spain
2. Department of Anaesthesiology, Emergency Medicine and Critical Care, General Hospital of Wiener Neustadt, 2700 Wiener Neustadt, Austria
3. Faculty of Medicine and Dentistry, Danube Private University (DPU), 3500 Krems, Austria
4. Department of Neurosurgery, Hospital Militar de Quito, Quito 170102, Ecuador
5. Statistics and Operations Research Department, UPC, Barcelona-Tech, 08034 Barcelona, Spain