Affiliation: | Department of Anesthesiology and Critical Care Medicine, Division of Neuroanesthesia, Johns Hopkins Medical Institution, Baltimore, MD;Department of Orthopaedic Surgery, Johns Hopkins University, 601 North Caroline Street, JHOC 5231, Baltimore, MD 21287-0882;Department of Orthopaedic Surgery, Johns Hopkins University, 601 N. Caroline Street, Suite 5243, Baltimore, MD 21287-0882 |