1. Department of Surgery, University of North Carolina School of Medicine , 101 Manning Drive Chapel Hill, North Carolina 27599 , USA
2. North Carolina Jaycee Burn Center , 101 Manning Drive Chapel Hill, North Carolina 27599 , USA
3. Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Hospital , 2301 Erwin Road Durham, North Carolina 27710 , USA
4. Department of Anesthesiology, University of North Carolina School of Medicine , 101 Manning Drive Chapel Hill, North Carolina 27599 , USA