[1] St Thomas Hosp, Dept Crit Care Med, Guys & St Thomas Natl Hlth Serv Fdn Trust, London, England
[2] Kings Coll London, Ctr Human & Appl Physiol Sci, Sch Basic & Med Biosci, London, England
[3] Univ Milano Bicocca, Dept Med & Surg, Monza, Italy
[4] Niguarda Ca Granda, Dept Anesthesia & Intens Care Med, Milan, Italy