1 Pulmonary, Critical Care and Sleep Medicine Service, Walter Reed National Military Medical Center, Bethesda, MD.
2 Pulmonary, Critical Care and Sleep Medicine Service, San Antonio Military Medical Center, San Antonio, TX.
3 Pulmonary, Critical Care and Sleep Medicine Service, Walter Reed National Military Medical Center, Bethesda, MD; Office for Student Affairs, F. Edward Hebert School of Medicine, The Uniformed Services University of the Health Sciences, Bethesda, MD. Electronic address: lisa.moores@usuhs.edu.