1 Division of Pulmonary, Allergy, Critical Care, and Sleep Medicine (A. C. M., S. M. N., C. S., I. J. B., B. J. M., and G. D. K.), University of Pittsburgh School of Medicine; the Department of Critical Care Medicine (I. J. B., D. B. W., and B. J. M.), University of Pittsburgh School of Medicine; and the Department of Medicine (H. Z.), University of Kentucky.