title: Cerebral tissue oxygen saturation during therapeutic hypothermia in post-cardiac arrest patients.
abstract: OBJECTIVE
  This observational study was performed to assess the cerebral tissue oxygen saturation during and after therapeutic hypothermia in comatose patients after out-of-hospital cardiac arrest.
  
  
  METHODS
  We performed a prospective observational study on the cerebral tissue oxygen saturation (SctO(2)) in post-cardiac arrest patients treated with therapeutic hypothermia (TH) between March 2011 and April 2012. SctO(2) (measured by near-infrared spectroscopy) was non-invasively and continuously measured in 28 post-cardiac arrest patients during hypothermia and active rewarming.
  
  
  RESULTS
  At the start of mechanically induced TH, SctO(2) was 68% (65-72) and PaCO(2) was 47.2 mmHg (36.9-51.4). SctO(2) and PaCO(2) significantly decreased to 59% (57-64; p=0.006) and 36.6 mmHg (33.9-44.7; p=0.002), respectively, within the first 3h of mechanically induced TH. Cerebral tissue oxygen saturation was significantly lower in non-survivors (n=10) compared with survivors (n=18) at 3h after induction of hypothermia (p=0.02) while the decrease in PaCO(2) was similar in both groups. During TH maintenance, SctO(2) gradually returned to baseline values (69% (63-72)) at 24h, with no differences between survivors and non-survivors (p=0.65). Carbon dioxide remained within the range of mild hypocapnia (32-38 mmHg) throughout the hypothermic period. During rewarming, SctO(2) further increased to 71% (67-78).
  
  
  CONCLUSIONS
  Induction of TH in comatose post-CA patients changes the balance between oxygen delivery and supply. The decrease in SctO(2) was less pronounced in patients surviving to hospital discharge.
authors: Fa Hasselt University, Agoralaan Gebouw D, 3590 Diepenbeek, Belgium. ingrid.meex@uhasselt.be
authors: Ingrid
authors: I
authors: Meex
authors: Jo
authors: J
authors: Dens
authors: Frank
authors: F
authors: Jans
authors: Willem
authors: W
authors: Boer
authors: Kristof
authors: K
authors: Vanhengel
authors: Guy
authors: G
authors: Vundelinckx
authors: René
authors: R
authors: Heylen
authors: Cathy
authors: C
authors: De Deyne
mesh_terms: D000368:Aged; D002245:Carbon Dioxide / Q000378:metabolism*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003128:Coma / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D008297:Male; D008875:Middle Aged; D058687:Out-of-Hospital Cardiac Arrest / Q000503:physiopathology / Q000628:therapy*; D010100:Oxygen / Q000378:metabolism*; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen