1. Critical Care Unit, Complexo Hospitalario Universitario A Coruña, CP. 15006, A Coruña, Spain
2. Critical Care Unit, Complexo Hospitalario Universitario de Santiago de Compostela, CP. 15702, Santiago de Compostela, Spain
3. Spinal Cord Injury Unit, Complexo Hospitalario Universitario A Coruña, CP. 15006, A Coruña, Spain
4. Department of Medicine, University of A Coruña, CP. 15006, A Coruña, Spain