title: Improved early postresuscitation EEG activity for animals treated with hypothermia predicted 96 hr neurological outcome and survival in a rat model of cardiac arrest.
abstract: OBJECTIVE
  To investigate the effect of hypothermia on 96 hr neurological outcome and survival by quantitatively characterizing early postresuscitation EEG in a rat model of cardiac arrest.
  
  
  METHODS
  In twenty male Sprague-Dawley rats, cardiac arrest was induced through high frequency transesophageal cardiac pacing. Cardiopulmonary resuscitation was initiated after 5 mins untreated arrest. Immediately after resuscitation, animals were randomized to either 2 hrs of hypothermia (N = 10) or normothermia (N = 10). EEG, ECG, aortic pressure, and core temperature were continuously recorded for 6 hrs. Neurological outcome was evaluated daily during the 96 hrs postresuscitation period.
  
  
  RESULTS
  No differences in the baseline measurements and resuscitation outcome were observed between groups. However, 96 hr neurological deficit score (204 ± 255 versus 500 ± 0, P = 0.005) and survival (6/10 versus 0/10, P = 0.011) were significantly better in the hypothermic group. Quantitative analysis of early postresuscitation EEG revealed that burst frequency and spectrum entropy were greatly improved in the hypothermic group and correlated with 96 hr neurological outcome and survival.
  
  
  CONCLUSIONS
  The improved burst frequency during burst suppression period and preserved spectrum entropy after restoration of continuous background EEG activity for animals treated with hypothermia predicted favorable neurological outcome and survival in this rat model of cardiac arrest.
authors.affiliation: School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing 400038, China.
authors.forename: Bihua
authors.initials: B
authors.lastname: Chen
authors.affiliation: Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors.forename: Feng-Qing
authors.initials: FQ
authors.lastname: Song
authors.affiliation: Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors.forename: Lei-Lei
authors.initials: LL
authors.lastname: Sun
authors.affiliation: Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors.forename: Ling-Yan
authors.initials: LY
authors.lastname: Lei
authors.affiliation: Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors.forename: Wei-Ni
authors.initials: WN
authors.lastname: Gan
authors.affiliation: Institute of Cardiovascular Diseases, The First Affiliated Hospital of Guangxi Medical University, Nanning 530021, China.
authors.forename: Meng-Hua
authors.initials: MH
authors.lastname: Chen
authors.affiliation: School of Biomedical Engineering, Third Military Medical University and Chongqing University, Chongqing 400038, China.
authors.forename: Yongqin
authors.initials: Y
authors.lastname: Li
mesh_terms: D000818:Animals; D001921:Brain / Q000503:physiopathology*; D016887:Cardiopulmonary Resuscitation / Q000379:methods; D004195:Disease Models, Animal; D004569:Electroencephalography; D019277:Entropy; D006321:Heart / Q000503:physiopathology*; D006324:Heart Arrest, Induced; D006801:Humans; D007036:Hypothermia, Induced; D051381:Rats