title: Prone position is associated with mild cerebral oxygen desaturation in elderly surgical patients.
abstract: OBJECTIVE
  A variety of hemodynamic and respiratory alterations accompany patients in the prone position; however the effect of the prone position on intraoperative cerebral saturation has not been studied. We sought to examine whether the incidence of cerebral oxygen desaturation in elderly patients (≥68 years of age) undergoing spine surgery in the prone position was more common than patients undergoing major surgery in the supine position.
  
  
  METHODS
  We performed a retrospective cohort study of 205 patients; 63 patients underwent surgery in the prone position and 142 in the supine position. Patients were evaluated for cerebral desaturation with bilateral cerebral oximetry. The primary predictor was position, secondary were: length of the surgery, incidence and duration of cerebral desaturation episodes at several thresholds, average time of Bispectral index below threshold of 45 in minutes, average electroencephalogram suppression ratio >0, amount of blood transfused, and the incidence of hypotension and hypertension.
  
  
  RESULTS
  Elderly spine surgery patients in the prone position were more than twice as likely to experience mild cerebral desaturation as patients in the supine position. Patients in the prone position had longer surgeries; however cerebral desaturation in the prone position was significantly more common even when adjusted for surgery time and the occurrence of intraoperative hypotension.
  
  
  CONCLUSIONS
  Cerebral desaturation is related to the prone position in elderly surgery patients. Future studies are necessary to determine whether this translates to a higher incidence of postoperative cognitive dysfunction and delirium.
authors.affiliation: Department of Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Outcomes Research Consortium, Cleveland, Ohio, United States of America.
authors.forename: Stacie
authors.initials: S
authors.lastname: Deiner
authors.affiliation: Department of Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Isaac
authors.initials: I
authors.lastname: Chu
authors.affiliation: Department of Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, United States of America.
authors.forename: Michelle
authors.initials: M
authors.lastname: Mahanian
authors.affiliation: Department of Health Evidence and Policy, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Hung-Mo
authors.initials: HM
authors.lastname: Lin
authors.affiliation: Department of Orthopedic Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Hecht
authors.affiliation: Department of Anesthesiology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Department of Surgery, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Department of Geriatrics and Palliative Care, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America; Outcomes Research Consortium, Cleveland, Ohio, United States of America.
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Silverstein
mesh_terms: D000368:Aged; D054022:Cerebrum / Q000378:metabolism*; D003710:Demography; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D016684:Prone Position / Q000502:physiology*; D016683:Supine Position; D013514:Surgical Procedures, Operative
chemical_list: D010100:Oxygen