[1] Hosp Sabadell Corp Sanitaia & Univ Parc Tauli, Crit Care Ctr, Sabadell, Spain
[2] Inst Salud Carlos III, CIBER Enfermedades Resp, Madrid, Spain
[3] Inst Univ Parc Tauli UAB, Fundacio Parc Tauli, Corp Sanitaria Parc Tauli, Sabadell, Spain
[4] Univ Int Calalunya, Fundacio Althaia, Serv Med Intens, Manresa, Spain
[5] Univ Trieste, Cattinara Hosp, Trieste, Italy
[6] Hosp Moises Broggi, St Joan Despi, Spain
[7] Univ Oviedo, Hosp Cent Asturias, E-33080 Oviedo, Spain
[8] Hosp Cent Def Gomez Ulla, Madrid, Spain
[9] Hosp Univ Virgen Nieves, Granada, Spain
[10] Hosp Univ Dr Negrin, MODERN, Res Unit, Las Palmas Gran Canaria, Spain
[11] Massachusetts Gen Hosp, Boston, MA 02114 USA
[12] Clin Bazterr & Clin Santa Isabel, Buenos Aires, DF, Argentina