title: Somatosensory and brainstem auditory evoked potentials in cardiac arrest patients treated with hypothermia.
abstract: OBJECTIVE
  To evaluate the prognostic value of short-latency median nerve somatosensory evoked potentials and brainstem auditory evoked potentials in outcome prediction for comatose cardiac arrest patients treated with hypothermia.
  
  
  METHODS
  Prospective, randomized, controlled trial of mild hypothermia after out-of-hospital cardiac arrest; a substudy of the European Hypothermia After Cardiac Arrest study.
  
  
  METHODS
  Intensive care unit of a tertiary referral hospital (Helsinki University Central Hospital).
  
  
  METHODS
  Sixty consecutive patients (aged 18-75 yrs) resuscitated from out-of-hospital ventricular fibrillation and comatose at 24 hrs after cardiac arrest; all patients were randomly assigned either to therapeutic hypothermia of 33 degrees C or normothermia.
  
  
  METHODS
  All patients received standard intensive care for at least 2 days. Patients randomized to hypothermia were cooled with an external cooling device for 24 hrs and then allowed to rewarm slowly for 12 hrs. In the normothermia group, the core temperature was kept below 38 degrees C with antipyretics and by physical means. The clinical outcome was assessed 6 months after cardiac arrest.
  
  
  RESULTS
  Somatosensory evoked potentials and brainstem auditory evoked potentials were recorded 24-28 hrs after cardiac arrest. All wave latencies were significantly prolonged in the hypothermia group. Bilaterally absent N20 waves predicted permanent coma with a specificity of 100% in both treatment groups. Brainstem auditory evoked potential recordings did not correlate with the outcome in either treatment group.
  
  
  CONCLUSIONS
  The prognostic ability of median nerve short-latency somatosensory evoked potentials does not seem to be affected by therapeutic hypothermia. Brainstem auditory evoked potentials had no additional value in outcome prediction.
authors.affiliation: Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Marjaana
authors.initials: M
authors.lastname: Tiainen
authors.forename: Tero T
authors.initials: TT
authors.lastname: Kovala
authors.forename: Olli S
authors.initials: OS
authors.lastname: Takkunen
authors.forename: Risto O
authors.initials: RO
authors.lastname: Roine
mesh_terms: D000328:Adult; D000368:Aged; D003128:Coma / Q000175:diagnosis* / Q000209:etiology; D016057:Evoked Potentials, Auditory, Brain Stem; D005073:Evoked Potentials, Somatosensory; D005260:Female; D006323:Heart Arrest / Q000150:complications / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced; D020925:Hypoxia-Ischemia, Brain / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D018709:Statistics, Nonparametric