1. Intensive Care Unit, Hospital Universitario de Canarias, La Laguna, Tenerife, 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, La Laguna, Tenerife, Spain
5. Laboratory Department, Hospital Universitario de Canarias, Santa Cruz de, Tenerife, Spain
6. Research Unit, Hospital Universitario de Canarias, La Laguna, Tenerife, Spain