title: Intra-arrest hypothermia during cardiac arrest: a systematic review.
abstract: BACKGROUND
  Therapeutic hypothermia is largely used to protect the brain following return of spontaneous circulation (ROSC) after cardiac arrest (CA), but it is unclear whether we should start therapeutic hypothermia earlier, that is, before ROSC.
  
  
  METHODS
  We performed a systematic search of PubMed, EMBASE, CINAHL, the Cochrane Library and Ovid/Medline databases using "arrest" OR "cardiac arrest" OR "heart arrest" AND "hypothermia" OR "therapeutic hypothermia" OR "cooling" as keywords. Only studies using intra-arrest therapeutic hypothermia (IATH) were selected for this review. Three authors independently assessed the validity of included studies and extracted data regarding characteristics of the studied cohort (animal or human) and the main outcomes related to the use of IATH: Mortality, neurological status and cardiac function (particularly, rate of ROSC).
  
  
  RESULTS
  A total of 23 animal studies (level of evidence (LOE) 5) and five human studies, including one randomized controlled trial (LOE 1), one retrospective and one prospective controlled study (LOE 3), and two prospective studies without a control group (LOE 4), were identified. IATH improved survival and neurological outcomes when compared to normothermia and/or hypothermia after ROSC. IATH was also associated with improved ROSC rates and with improved cardiac function, including better left ventricular function, and reduced myocardial infarct size, when compared to normothermia.
  
  
  CONCLUSIONS
  IATH improves survival and neurological outcome when compared to normothermia and/or conventional hypothermia in experimental models of CA. Clinical data on the efficacy of IATH remain limited.
authors.affiliation: Department of Intensive Care, Erasme Hospital, Université libre de Bruxelles, Route de Lennik 808, 1070 Brussels, Belgium.
authors.forename: Sabino
authors.initials: S
authors.lastname: Scolletta
authors.forename: Fabio Silvio
authors.initials: FS
authors.lastname: Taccone
authors.forename: Per
authors.initials: P
authors.lastname: Nordberg
authors.forename: Katia
authors.initials: K
authors.lastname: Donadello
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Vincent
authors.forename: Maaret
authors.initials: M
authors.lastname: Castren
mesh_terms: D000818:Animals; D006323:Heart Arrest / Q000401:mortality / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods* / Q000401:mortality; D020127:Recovery of Function; D013997:Time Factors