1. Anesthesiology and Surgical Critical Care Department, Hospital Universitario La Paz, Madrid, Spain.
2. Anesthesiology and Surgical Critical Care Department, Hospital Clínico Universitario, Valladolid, Spain.
3. Anesthesiology and Surgical Critical Care Department, Hospital del Mar, Barcelona, Spain.
4. Anesthesiology and Surgical Critical Care Department, Hospital Universitario La Princesa, Madrid, Spain.
5. PRISM-AG, Madrid, Spain.
6. Preventive Medicine Department, Hospital Infanta Cristina, Parla, Madrid, Spain.