title: Greater temperature variability is not associated with a worse neurological outcome after cardiac arrest.
abstract: OBJECTIVE
  Spontaneous alterations in temperature homeostasis after cardiac arrest (CA) are associated with worse outcome. However, it remains unclear the prognostic role of temperature variability (TV) during cooling procedures. We hypothesized that low TV during targeted temperature management (TTM) would be associated with a favourable neurological outcome after CA.
  
  
  METHODS
  We reviewed data from all comatose patients after in-hospital or out-of-hospital CA admitted to our Department of Intensive Care between December 2006 and January 2014 who underwent TTM (32-34°C) and survived at least 24h. We collected demographic data, CA characteristics, intensive care unit (ICU) survival and neurological outcome at three months (favourable neurological outcome was defined as cerebral performance category 1-2). TV was expressed using the standard deviation (SD) of all temperature measurements during hypothermia; high TV was defined as an SD >1°C.
  
  
  RESULTS
  Of the 301 patients admitted over the study period, 72 patients were excluded and a total of 229 patients were studied; 88 had a favourable neurological outcome. The median temperature on ICU admission was 35.8 [34.9-36.9]°C and the median time to hypothermia (body temperature <34°C), was 4 [3-7] h. Median TV was 0.9 [0.6-1.0]°C and 57 patients (25%) had high TV. In multivariable logistic regression, witnessed CA, ventricular fibrillation/tachycardia and previous neurological disease were independent risk factors for high TV. Younger age, bystander cardiopulmonary resuscitation, shorter time to return of spontaneous circulation, cardiac origin of arrest, shockable rhythm and longer time to target temperature were independent predictors of favourable neurological outcome, but TV was not.
  
  
  CONCLUSIONS
  Among comatose survivors treated with TTM after CA, 25% of patients had high TV; however, this was not associated with a worse neurologic outcome.
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium; Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anaesthesia and Intensive Care, San Raffaele Hospital, Via Olgettina 60, 20132 Milan, Italy.
authors.forename: Leda
authors.initials: L
authors.lastname: Nobile
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Irene
authors.initials: I
authors.lastname: Lamanna
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Vito
authors.initials: V
authors.lastname: Fontana
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Katia
authors.initials: K
authors.lastname: Donadello
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Antonio Maria
authors.initials: AM
authors.lastname: Dell'anna
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Jacques
authors.initials: J
authors.lastname: Creteur
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.affiliation: Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anaesthesia and Intensive Care, San Raffaele Hospital, Via Olgettina 60, 20132 Milan, Italy.
authors.forename: Federico
authors.initials: F
authors.lastname: Pappalardo
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université Libre de Bruxelles, Route de Lennik, 808, 1070 Brussels, Belgium. Electronic address: ftaccone@ulb.ac.be.
authors.forename: Fabio Silvio
authors.initials: FS
authors.lastname: Taccone
mesh_terms: D000368:Aged; D001530:Belgium / Q000453:epidemiology; D001833:Body Temperature Regulation / Q000502:physiology*; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D005260:Female; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology; D058687:Out-of-Hospital Cardiac Arrest / Q000150:complications / Q000401:mortality / Q000628:therapy*; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends
keywords: Fever; Homeostasis; Hypothermia; Outcome; Post-anoxic