1. Department of Respiratory Medicine, Hospital Universitario de Getafe, Universidad Europea de Madrid (UEM), Getafe, Spain;
2. Biochemistry Laboratory, Hospital Universitario de Getafe, Getafe, Spain;
3. Department of Emergency, Hospital Universitario de Getafe, Getafe, Spain;
4. Department of Intensive Care, CIBERES of Respiratory Diseases (CIBERES) Hospital Universitario de Getafe, Getafe, Spain