1. Departments of Anesthesiology, Perioperative and Pain Medicine, and
2. Department of Neurosurgery, Duke University Medical Center, Durham, North Carolina; and
3. Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Hospital, Harvard Medical School, Boston, Massachusetts
4. Neurosurgery, Brigham & Women’s Hospital, Harvard Medical School, Boston, Massachusetts;