1Department of Anesthesiology, Uniformed Services University, Bethesda, Maryland, USA
2Henry M. Jackson Foundation For the Advancement of Military Medicine, Rockville, Maryland, USA
3School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
4Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina, USA
5Department of Orthopaedic Surgery, Brooke Army Medical Center, Fort Sam Houston, Texas, USA
6Department of Surgery, Uniformed Services University, Bethesda, Maryland, USA
7Department of Anesthesiology, Brooke Army Medical Center, Fort Sam Houston, Texas, USA
8Nell Hodgson Woodruff School of Nursing, Emory University, Atlanta, Georgia, USA