1 Intensive Care Department, King Abdulaziz Medical City, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences and King Abdullah International Medical Research Center, MC 1425, P.O. Box 22490, 11426, Riyadh, Saudi Arabia. Arabi@ngha.med.sa.
2 Department of Intensive Care, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.