title: A feasibility study of cerebral oximetry monitoring during the post-resuscitation period in comatose patients following cardiac arrest.
abstract: BACKGROUND
  One of the major causes of death and neurological injury after cardiac arrest is delayed ischemia combined with oxygen free radical mediated reperfusion injury. Consequently determining the optimal balance between oxygen delivery and uptake in the brain using a reliable non-invasive monitoring system during the post-resuscitation period is of importance. In this observational study, we evaluated the feasibility of using cerebral oximetry during the post-resuscitation period in order to identify changes in regional cerebral oxygen saturation (rSO2) and its association with survival to discharge.
  
  
  METHODS
  21 consecutive patients admitted to the intensive care units following cardiac arrest had cerebral oximetry monitoring carried out for 48 h. Mean rSO2 values were collected during the first 24h and then again during the subsequent 24-48 h of the post-resuscitation period.
  
  
  RESULTS
  43% (n=9) patients survived to hospital discharge and 57% (n=12) died. Amongst all patients the median (IQR) rSO2% was 65.5% (62.6-68.2) in the first 24-h following ROSC and increased to 72.1% (64.6-73.7) (p=0.11) in the subsequent 24-48 h. The median (IQR) rSO2% during the first 24 h in patients who survived to discharge compared to those who did not survive were significantly higher 68.2% (66.0-71.0) vs. 62.9% (56.5-66.0), p=0.01). During the subsequent 24-48 h period, while a difference in the rSO2 between survivors and non-survivors was noted, this did not achieve statistical significance (median (IQR): 73.7 (70.2-74.0) vs. 66.5 (58.2-72.1), p=0.11).
  
  
  CONCLUSIONS
  Our study indicates that the use of cerebral oximetry is feasible during the post resuscitation period after cardiac arrest. Further studies are needed to determine whether cerebral oximetry may be used as a novel non-invasive monitoring system to evaluate changes in the balance between cerebral oxygen delivery and uptake during the post-resuscitation period.
authors.affiliation: Resuscitation Research Group, State University of New York at Stony Brook, Stony Brook Medical Center, T17-040 Health Sciences Center, Stony Brook, NY 11794-8172, USA.
authors.forename: Anna
authors.initials: A
authors.lastname: Ahn
authors.affiliation: Resuscitation Research Group, State University of New York at Stony Brook, Stony Brook Medical Center, T17-040 Health Sciences Center, Stony Brook, NY 11794-8172, USA.
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.affiliation: Resuscitation Research Group, State University of New York at Stony Brook, Stony Brook Medical Center, T17-040 Health Sciences Center, Stony Brook, NY 11794-8172, USA.
authors.forename: Loren
authors.initials: L
authors.lastname: Inigo-Santiago
authors.affiliation: Resuscitation Research Group, State University of New York at Stony Brook, Stony Brook Medical Center, T17-040 Health Sciences Center, Stony Brook, NY 11794-8172, USA. Electronic address: sam.parnia@stonybrookmedicine.edu.
authors.forename: Sam
authors.initials: S
authors.lastname: Parnia
mesh_terms: D000368:Aged; D001921:Brain / Q000378:metabolism*; D003128:Coma / Q000209:etiology / Q000378:metabolism* / Q000401:mortality; D005240:Feasibility Studies; D005260:Female; D006323:Heart Arrest / Q000378:metabolism* / Q000401:mortality* / Q000628:therapy; D006760:Hospitalization; D006801:Humans; D008297:Male; D008875:Middle Aged; D010092:Oximetry; D010101:Oxygen Consumption / Q000502:physiology*; D012151:Resuscitation; D019265:Spectroscopy, Near-Infrared; D013997:Time Factors
keywords: Cardiac arrest; Cerebral oximetry; Cerebral perfusion; Near-infrared spectroscopy (NIRS); Post resuscitation; Regional cerebral oxygen saturation