1. Department of Anesthesiology and Critical Care Medicine, Johns Hopkins School of Medicine, Baltimore, USA
2. Department of Anesthesiology, Walter Reed National Military Medical Center, Bethesda, USA
3. Department of Anesthesiology, Neurology, Psychiatry & Orthopaedics and Rehabilitation, University of Florida, Gainesville, USA
4. Department of Anesthesiology and Critical Care Medicine and Physical Medicine & Rehabilitation, Johns Hopkins School of Medicine, and Walter Reed National Military Medical Center, Baltimore, USA