From the Department of Medicine, Section of Pulmonary and Critical Care (JPK, ASP, CN, KM, JBH, JPK) and Therapy Services (AJP, CLE, LS, MM, MF, DD) University of Chicago, Chicago, IL; Department of Medicine (WDS), Division of Pulmonary, Allergy and Critical Care Medicine, University of Pennsylvania, Philadelphia, PA; and the Department of Medicine, Division of Pulmonary and Critical Care (GAS, AB) and Therapy Services (RB), University of Iowa, Iowa City, IA.