1 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; Lung Health Center, Birmingham, AL.
2 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Medicine, University of Alabama at Birmingham, Birmingham, AL; Lung Health Center, Birmingham, AL; Acute Care Service, Birmingham VA Medical Center, Birmingham, AL. Electronic address: jmwells@uabmc.edu.