title: Assessment of cerebral oxygenation in neurocritical care patients: comparison of a new four wavelengths forehead regional saturation in oxygen sensor (EQUANOX®) with brain tissue oxygenation. A prospective observational study.
abstract: BACKGROUND
  Because of restricted information given by monitoring solely intracranial pressure and cerebral perfusion pressure, assessment of the cerebral oxygenation in neurocritical care patients would be of interest. The aim of this study was to determinate the correlation between the non-invasive measure regional saturation in oxygen (rSO2) with a third generation NIRS monitor and an invasive measure of brain tissue oxygenation tension (PbtO2).
  
  
  METHODS
  We conducted a prospective, observational, unblinded study including neurocritical care patients requiring a PbtO2 monitoring. Concomitant measurements of rSO2 were performed with a four wavelengths forehead sensor (EQUANOX Advance®) of the EQUANOX® 7600 System. We determined the correlation between rSO2 and PbtO2 and the ability of the rSO2 to detect ischemic episodes defined by a PbtO2 less than 15 mmHg. The rSO2 ischemic threshold was 60%.
  
  
  RESULTS
  During 2 months, 8 consecutives patients, including 275 measurements, were studied. There was no correlation between rSO2 and PbtO2 (r=0.016 [-0.103-0.134], r2=0.0003, P=0.8). On the 86 ischemic episodes detected by PbtO2, only 13 were also detected by rSO2. ROC curve showed the inability for rSO2 to detect cerebral hypoxia episodes (AUC=0.54).
  
  
  CONCLUSIONS
  rSO2 cannot be used as a substitute for PbtO2 to monitor cerebral oxygenation in neurocritical care patients.
authors.affiliation: Intensive Care Unit, Sainte Anne Military Teaching Hospital, Toulon, France - pierre.esnault@gmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Esnault
authors.forename: H
authors.initials: H
authors.lastname: Boret
authors.forename: A
authors.initials: A
authors.lastname: Montcriol
authors.forename: E
authors.initials: E
authors.lastname: Carre
authors.forename: B
authors.initials: B
authors.lastname: Prunet
authors.forename: J
authors.initials: J
authors.lastname: Bordes
authors.forename: P
authors.initials: P
authors.lastname: Simon
authors.forename: C
authors.initials: C
authors.lastname: Joubert
authors.forename: A
authors.initials: A
authors.lastname: Dagain
authors.forename: E
authors.initials: E
authors.lastname: Kaiser
authors.forename: E
authors.initials: E
authors.lastname: Meaudre
mesh_terms: D000328:Adult; D000368:Aged; D001923:Brain Chemistry; D003422:Critical Care / Q000379:methods*; D005260:Female; D005546:Forehead; D006801:Humans; D002534:Hypoxia, Brain / Q000175:diagnosis* / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000628:therapy*; D010092:Oximetry / Q000379:methods*; D010101:Oxygen Consumption; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared; D055815:Young Adult