1. Intensive Care Unit, Hospital Universitario de Canarias. Ofra, La Laguna, Spain
2. Intensive Care Unit, Hospital Universitario Nuestra Señora Candelaria, Santa Cruz Tenerife, Spain
3. Intensive Care Unit, Hospital General de La Palma, La Palma, Spain
4. Laboratory Department, Hospital Universitario de Canarias. Ofra, La Laguna, Spain
5. Research Unit, Hospital Universitario de Canarias. Ofra, La Laguna, Spain