1. Department of Medicine, McGill University, Montreal, Quebec, Canada
2. Regroupement de Soins Critiques Respiratoires, Réseau de Santé Respiratoire, Fonds de Recherche du Québec-Santé, Montréal, Québec, Canada
3. School of Pharmacy, Northeastern University, Boston, Massachusetts; and
4. Department of Pulmonary, Critical Care, and Sleep Medicine, Tufts Medical Center, Boston, Massachusetts