1. Intensive Care Department, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, King Abdullah International Medical Research Center, King Abdulaziz Medical City, Riyadh, Saudi Arabia
2. Division of Pulmonary, Critical Care, and Sleep Medicine, Ohio State Wexner Medical, Center, Columbus, Ohio; and
3. Department of Medicine, Pulmonary Center, Boston University School of Medicine, Boston, Massachusetts