1. Anesthesiology Department, Hospital Quironsalud Marbella, 29680 Marbella, Spain
2. Otorhinolaryngology Department, Hospital Quironsalud Marbella, 29680 Marbella, Spain
3. Otorhinolaryngology Department, Hospital Quironsalud Campo de Gibraltar, 11379 Palmones, Spain
4. Neumology Department, Hospital Quironsalud Marbella, 29680 Marbella, Spain
5. Otorhinolaryngology Department, Hospital Universitario de Fuenlabrada, Universidad Rey Juan Carlos, 28943 Madrid, Spain
6. Otorhinolaryngology Department, Hospital Sanitas la Zarzuela, 28023 Madrid, Spain
7. Otorhinolaryngology Department, Clínica Universitaria de Navarra, 31008 Pamplona, Spain