| Affiliation: | 1. Pain Unit, Department of Anesthesiology and Reanimation, “Virgen de la Salud” University Hospital, Toledo Hospital Complex, Toledo, Spain;2. Pain Study and Treatment Unit, “Ramón y Cajal” University Hospital, Madrid, Spain;3. Pain Unit, Department of Anesthesiology and Reanimation, Gregorio Mara?ón University General Hospital, Madrid, Spain;4. Puerta de Hierro Majadahonda University Hospital, Madrid, Spain;5. Pain Unit, 12 October University Hospital, Madrid, Spain;6. Pain Unit, Department of Anesthesiology, Fuenlabrada University Hospital, Madrid, Spain;7. Pain Unit, Department of Anesthesiology, “Ruber Internacional” Hospital, Madrid, Spain;8. Pain Unit, Department of Anesthesiology and Reanimation, “Infanta Cristina” University Hospital, Parla, Madrid, Spain;9. Pain Unit, Jiménez‐Díaz Foundation University Hospital, Madrid, Spain;10. Pain Unit, Madrid‐Montepríncipe University Hospital, Madrid, Spain;11. Pain Unit, Ciudad Real University Hospital, Ciudad Real, Spain;12. Pain Unit, Department of Anesthesiology and Reanimation, “Infanta Sofía” University Hospital, Madrid, Spain;13. Pain Unit, Department of Anesthesiology and Reanimation, “San Carlos” Clínical Hospital, Madrid, Spain;14. Department of Anesthesiology and Reanimation, Prince of Asturias University, Hospital, Alcalá de Henares, Madrid, Spain;15. Pain Unit, Department of Anesthesiology and Reanimation, “Severo Ochoa” University Hospital, Leganés, Madrid, Spain;16. Pain Unit, Department of Anesthesiology, idcsalud Group Sur Hospital, Alcorcón, Madrid, Spain |
