ONLINE FIRST This is an Online First, unedited version of this article. The final, edited version will appear in a numbered issue of CHEST and may contain substantive changes. We encourage readers to check back for the final article. Online First papers are indexed in PubMed and by search engines, but the information, including the final title and author list, may be updated on final publication. http://journal.publications.chestnet.org/ Online First articles are not copyedited prior to posting. ©American College of Chest Physicians. Reproduction of this article is prohibited without written permission from the American College of Chest Physicians. See online for more details. Page 1 of 14 Downloaded From: http://journal.publications.chestnet.org/ by a Houston Academy of Medicine User on 11/25/2015