1. Uniformed Services University of the Health Sciences , Bethesda, MD 20814 , USA
2. Department of Anesthesiology, Brooke Army Medical Center , Fort Sam Houston, TX 78234 , USA
3. Department of Anesthesiology, University of Colorado School of Medicine , Aurora, CO 80045 , USA
4. Department of Emergency Medicine, University of Colorado School of Medicine , Aurora, CO 80045 , USA
5. Center for Combat and Battlefield (COMBAT) Research, University of Colorado School of Medicine , Aurora, CO 80045 , USA
6. Department of Trauma, Brooke Army Medical Center , Fort Sam Houston, TX 78234 , USA