title: Absent SEP during therapeutic hypothermia did not reappear after re-warming in comatose patients following cardiac arrest.
abstract: BACKGROUND
  Early prediction of neurological outcome for patients resuscitated from cardiac arrest (CA) is a challenging task. Therapeutic hypothermia (TH) has been shown to improve neurological outcome after CA. Two recent studies indicated that somatosensory evoked potentials (SEP) recorded during TH retains high prediction value for poor neurological outcome. It remains unclear whether TH can influence the recovery of bilaterally absent (BA) N20 after re-warming. The primary endpoint of the present study was to evaluate if patients with BA SEPs during TH can recover cortical responses after re-warming. The secondary endpoint was to evaluate whether BA SEPs recorded during TH retains its prediction value for poor neurological outcome as in normothermic patients.
  
  
  METHODS
  A single centre prospective cohort study including comatose adults resuscitated from in/out-of-hospital CA treated with TH. SEPs were recorded during TH (6-24 hours after CA) and after re-warming in those patients who remained comatose. Neurological outcome was assessed 6 months after CA using the Glasgow Outcome Scale.
  
  
  RESULTS
  Sixty patients were included. In patients with preserved SEP, no significant differences were found between N20 mean amplitude during TH and after re-warming. During TH, 24 patients showed bilaterally absent N20 but none of these recovered cortical responses after re-warming. All patients with absent SEPs during TH did not recover consciousness.
  
  
  CONCLUSIONS
  In a single centre cohort of comatose CA patients, our results showed that all patients with absent SEPs during early recording (6-24 hours) during TH showed bilaterally absent SEPs after re-warming. As a secondary result we confirmed previous data that BA SEPs during TH retains its prognostic value for poor neurological outcome, as in normothermic patients.
authors: Clinical Neurophysiology Unit, Neuroscience Department, Careggi Teaching Hospital, Florence, Italy. agrippo@unifi.it
authors: A
authors: A
authors: Grippo
authors: R
authors: R
authors: Carrai
authors: S
authors: S
authors: Fossi
authors: C
authors: C
authors: Cossu
authors: E
authors: E
authors: Mazzeschi
authors: A
authors: A
authors: Peris
authors: M
authors: M
authors: Bonizzoli
authors: M
authors: M
authors: Ciapetti
authors: G F
authors: GF
authors: Gensini
authors: F
authors: F
authors: Pinto
authors: A
authors: A
authors: Amantini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D003128:Coma / Q000503:physiopathology*; D004569:Electroencephalography; D023381:Endpoint Determination; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D015600:Glasgow Coma Scale; D023261:Glasgow Outcome Scale; D006323:Heart Arrest / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced; D008297:Male; D008475:Median Nerve / Q000502:physiology; D008875:Middle Aged; D011446:Prospective Studies; D017694:Rewarming / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult