[1] Univ Toronto, Interdept Div Crit Care Med, Toronto, ON, Canada
[2] Hosp Univ Getafe, Madrid, Spain
[3] CIBER Enfermedades Resp, Madrid, Spain
[4] Univ Texas San Antonio, San Antonio, TX USA
[5] Sanatorio Mitre, Buenos Aires, DF, Argentina
[6] Univ Pontificia Bolivariana, Medellin, Colombia
[7] Hosp Mil Quito, Quito, Ecuador