[1] Veterans Affairs (VA) Tennessee Valley Healthcare System,Nashville VA Medical Center
[2] Vanderbilt University School of Medicine,Division of Trauma and Surgical Critical Care, Departments of Surgery and Neurosurgery, Section of Surgical Sciences
[3] Department of Rehabilitation and Aged Care Unit Hospital Ancelle,Division of Critical Care, Department of Anesthesiology
[4] Geriatric Research Group,undefined
[5] Vanderbilt University School of Medicine,undefined