title: Continuous electrodermal activity as a potential novel neurophysiological biomarker of prognosis after cardiac arrest--A pilot study.
abstract: OBJECTIVE
  Neurological outcome prognosis remains challenging in patients undergoing therapeutic hypothermia (TH) after cardiac resuscitation. Technological advances allow for a novel wrist-worn device to continuously record electrodermal activity (EDA), a measure of pure sympathetic activity.
  
  
  METHODS
  A prospective cohort study was performed to determine the yield of continuous EDA in patients treated with TH for coma after cardiac arrest during hypothermia and normothermia. Association between EDA parameters (event-related and nonspecific electrodermal responses (ER-EDR, NS-EDR)) and outcome measures (cerebral performance category [CPC]) (Full Outline in UnResponsivenss (FOUR) score) were assessed.
  
  
  RESULTS
  Eighteen patients were enrolled. Total number of EDR (66.4 vs 12.0/24h, p = 0.02), ER-EDR (39.5 vs 11.2/24h, p = 0.009), median amplitude change of all EDR (0.08 vs 0.03 μSI, p = 0.03) and ER-EDR (0.14 vs 0.05 μSI, p = 0.025) were higher in patients with favorable (CPC 1-2) versus poor outcome (CPC 3-5) during hypothermia. Greater differences in EDA parameters were observed during hypothermia than normothermia. The FOUR score was correlated to the number of all EDR and median amplitudes.
  
  
  CONCLUSIONS
  Continuous EDA potentially opens a new avenue for autonomic function monitoring in neurocritically ill patients. It is feasible in the ICU setting, even during hypothermic states. As a measure of a complete neurophysiological circuit, it may be a novel neurophysiologic biomarker of outcome after cardiac resuscitation.
authors.affiliation: Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Neurology Department, Hopital du Valais, Sion, Switzerland.
authors.forename: Vincent
authors.initials: V
authors.lastname: Alvarez
authors.affiliation: Department Sport & Gesundheit, Sportmedizinisches Institut, Universität Paderborn, Paderborn, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Reinsberger
authors.affiliation: Department of Cardiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Scirica
authors.affiliation: Department of Cardiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Molly H
authors.initials: MH
authors.lastname: O'Brien
authors.affiliation: Department of Nursing, Cardiac Intensive Care Unit, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Kathleen R
authors.initials: KR
authors.lastname: Avery
authors.affiliation: Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Galen
authors.initials: G
authors.lastname: Henderson
authors.affiliation: Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA. Electronic address: jlee38@partners.org.
authors.forename: Jong Woo
authors.initials: JW
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis / Q000209:etiology; D016887:Cardiopulmonary Resuscitation / Q000009:adverse effects / Q000379:methods; D003128:Coma / Q000209:etiology / Q000628:therapy; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology*; D006323:Heart Arrest / Q000150:complications / Q000628:therapy; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D010043:Outcome and Process Assessment, Health Care; D010865:Pilot Projects; D011379:Prognosis; D014481:United States
keywords: Anoxic brain injury; Cardiac arrest; Electrodermal activity; Electroencephalography; Prognosis; Therapeutic hypothermia