1 Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, and Shock Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD Shock Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, and Shock Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD Shock Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, and R Adams Cowley Shock Trauma Center, Baltimore, MD Department of Anesthesiology, University of Maryland School of Medicine, Baltimore, MD, Shock Trauma and Anesthesiology Research Center, University of Maryland School of Medicine, Baltimore, MD, and R Adams Cowley Shock Trauma Center, Baltimore, MD.