title: Prediction of cognitive dysfunction after resuscitation from out-of-hospital cardiac arrest using serum neuron-specific enolase and protein S-100.
abstract: BACKGROUND
  More than 50% of patients initially resuscitated from out-of-hospital cardiac arrest die in hospital.
  
  
  OBJECTIVE
  To investigate the prognostic value of serum protein S-100 and neuron-specific enolase (NSE) concentrations for predicting (a) memory impairment at discharge; (b) in-hospital death, after resuscitation from out-of-hospital cardiac arrest.
  
  
  METHODS
  In a prospective study of 143 consecutive survivors of out-of-hospital cardiac arrest, serum samples were obtained within 12, 24-48 and 72-96 hours after the event. S-100 and NSE concentrations were measured. Pre-discharge cognitive assessment of patients (n = 49) was obtained by the Rivermead Behavioural Memory Test (RBMT). The relationship between biochemical brain marker concentrations and RBMT scores, and between marker concentrations and the risk of in-hospital death was examined.
  
  
  RESULTS
  A moderate negative relationship was found between S-100 concentration and memory test score, at all time points. The relationship between NSE and memory test scores was weaker. An S-100 concentration >0.29 microg/l at time B predicted moderate to severe memory impairment with absolute specificity (42.8% sensitivity). S-100 remained an independent predictor of memory function after adjustment for clinical variables and cardiac arrest timing indices. NSE and S-100 concentrations were greater in patients who died than in those who survived, at all time points. Both NSE and S-100 remained predictors of in-hospital death after adjustment for clinical variables and cardiac arrest timing indices. The threshold concentrations yielding 100% specificity for in-hospital death were S-100: 1.20 microg/l (sensitivity 44.8%); NSE 71.0 microg/l (sensitivity 14.0%).
  
  
  CONCLUSIONS
  Estimation of serum S-100 concentration after out-of-hospital cardiac arrest can be used to identify patients at risk of significant cognitive impairment at discharge. Serum S-100 and NSE concentrations measured 24-48 hours after cardiac arrest provide useful additional information.
authors.affiliation: Department of Cardiology, Royal Infirmary of Edinburgh, Edinburgh, UK. neil.grubb@btopenworld.com
authors.forename: Neil R
authors.initials: NR
authors.lastname: Grubb
authors.forename: Catriona
authors.initials: C
authors.lastname: Simpson
authors.forename: Roy A
authors.initials: RA
authors.lastname: Sherwood
authors.forename: Hagosa D
authors.initials: HD
authors.lastname: Abraha
authors.forename: Stuart M
authors.initials: SM
authors.lastname: Cobbe
authors.forename: Ronan E
authors.initials: RE
authors.lastname: O'Carroll
authors.forename: Ian
authors.initials: I
authors.lastname: Deary
authors.forename: Keith A A
authors.initials: KA
authors.lastname: Fox
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism; D016887:Cardiopulmonary Resuscitation / Q000379:methods* / Q000401:mortality; D003128:Coma / Q000097:blood; D004632:Emergency Medical Services; D005260:Female; D006323:Heart Arrest / Q000401:mortality / Q000523:psychology* / Q000628:therapy; D017052:Hospital Mortality; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D008875:Middle Aged; D015999:Multivariate Analysis; D010751:Phosphopyruvate Hydratase / Q000378:metabolism*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D009418:S100 Proteins / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D009418:S100 Proteins; D010751:Phosphopyruvate Hydratase