title: Poor outcome prediction by burst suppression ratio in adults with post-anoxic coma without hypothermia.
abstract: OBJECTIVE
  Burst suppression ratio (BSR) is a quantitative electroencephalography (qEEG) parameter. The purpose of our study was to compare the accuracy of BSR when compared to other EEG parameters in predicting poor outcomes in adults who sustained post-anoxic coma while not being subjected to therapeutic hypothermia.
  
  
  METHODS
  EEG was registered and recorded at least once within 7 days of post-anoxic coma onset. Electrodes were placed according to the international 10-20 system, using a 16-channel layout. Each EEG expert scored raw EEG using a grading scale adapted from Young and scored amplitude-integrated electroencephalography tracings, in addition to obtaining qEEG parameters defined as BSR with a defined threshold. Glasgow outcome scales of 1 and 2 at 3 months, determined by two blinded neurologists, were defined as poor outcome.
  
  
  RESULTS
  Sixty patients with Glasgow coma scale score of 8 or less after anoxic accident were included. The sensitivity (97.1%), specificity (73.3%), positive predictive value (82.5%), and negative prediction value (95.0%) of BSR in predicting poor outcome were higher than other EEG variables. BSR1 and BSR2 were reliable in predicting death (area under the curve > 0.8, P < 0.05), with the respective cutoff points being 39.8% and 61.6%. BSR1 was reliable in predicting poor outcome (area under the curve  =  0.820, P < 0.05) with a cutoff point of 23.9%. BSR1 was also an independent predictor of increased risk of death (odds ratio  =  1.042, 95% confidence intervals: 1.012-1.073, P  =  0.006).
  
  
  CONCLUSIONS
  BSR may be a better predictor in prognosticating poor outcomes in patients with post-anoxic coma who do not undergo therapeutic hypothermia when compared to other qEEG parameters.
authors.forename: Qinglin
authors.initials: Q
authors.lastname: Yang
authors.forename: Yingying
authors.initials: Y
authors.lastname: Su
authors.forename: Mohammed
authors.initials: M
authors.lastname: Hussain
authors.forename: Weibi
authors.initials: W
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Ye
authors.forename: Daiquan
authors.initials: D
authors.lastname: Gao
authors.forename: Fei
authors.initials: F
authors.lastname: Tian
mesh_terms: D000328:Adult; D001921:Brain / Q000503:physiopathology*; D003128:Coma / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology*; D004569:Electroencephalography; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012306:Risk; D012680:Sensitivity and Specificity
keywords: Amplitude-integrated electroencephalography,; Burst suppression ratio,; Electroencephalography,; Outcome; Post-anoxic coma,; Quantitative electroencephalography,