aDepartment of Anesthesiology, Wake Forest University School of Medicine (WFUSM), Winston-Salem, NC, United States

bDepartment of Orthopaedic Surgery, WFUSM, Winston-Salem, NC, United States,

cDepartment of Anesthesiology and Perioperative Medicine, Harvard Medical School, Massachusetts General Hospital, Boston, MA, United States

*Corresponding author. Address: Department of Anesthesiology, Wake Forest University School of Medicine, 1 Medical Center Boulevard, Winston Salem, NC 27157-1009, United States. Tel.: +1 336-716-4182; fax: +1 336-716-0288. E-mail address: [email protected] (J.C. Eisenach).

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