[1] Neurol Inst Besta, Dept Neuroanesthesia, I-20136 Milan, Italy
[2] Leeds Gen Infirm, Leeds, W Yorkshire, England
[3] Univ Cattolica Sacro Cuore, Dept Surg, Rome, Italy
[4] Northside Hosp Forsyth, Dept Emergency Med, Atlanta, GA USA
[5] Univ Penn, Perelman Sch Med, Philadelphia, PA 19104 USA
[6] King Saud Univ Hlth Sci, Natl & Gulf Ctr Evidence Based Hlth Practice, Riyadh, Saudi Arabia
[7] Clin Univ St Luc, Dept Anesthesia & Intens Care Med, B-1200 Brussels, Belgium
[8] Gen State Hosp Athens, Intens Care Unit, Athens, Greece
[9] Greater Baltimore Med Ctr, Baltimore, MD USA
[10] Childrens Hosp & Res Ctr, Oakland, CA 94609 USA
[11] Univ Cattolica Sacro Cuore, Infect Dis Unit, Rome, Italy
[12] Johns Hopkins Univ Hosp, Baltimore, MD 21287 USA
[13] SHR Zent Klinikum Suhl, Dept Anesthesiol & Intens Care Med, Jena, Germany
[14] European Inst Oncol, Div Abdominopelv Surg, Milan, Italy
[15] Inst Gustave Roussy, Dept Anesthesia, Villejuif, France
[16] New York Methodist Hosp, Dept Emergency Med, New York, NY USA
[17] Clin Epidemiol Unit, New York, NY USA
[18] Childrens Natl Med Ctr, Dept Anesthesiol, Washington, DC 20010 USA