title: Pre-hospital versus in-hospital initiation of cooling for survival and neuroprotection after out-of-hospital cardiac arrest.
abstract: BACKGROUND
  Targeted temperature management (also known under 'therapeutic hypothermia', 'induced hypothermia'", or 'cooling') has been shown to be beneficial for neurological outcome in patients who have had successful resuscitation from sudden cardiac arrest, but it remains unclear when this intervention should be initiated.
  
  
  OBJECTIVE
  To assess the effects of pre-hospital initiation of cooling on survival and neurological outcome in comparison to in-hospital initiation of cooling for adults with pre-hospital cardiac arrest.
  
  
  METHODS
  We searched CENTRAL, MEDLINE, EMBASE, CINAHL, BIOSIS, and three trials registers from inception to 5 March 2015, and carried out reference checking, citation searching, and contact with study authors to identify additional studies.
  
  
  METHODS
  We searched for randomized controlled trials (RCTs) in adults with out-of-hospital cardiac arrest comparing cooling in the pre-hospital setting to in-hospital cooling. Our primary outcomes were survival and neurological outcome; our secondary outcomes were adverse events, quality of life, and length of stay in the intensive care unit (ICU) and in the hospital.
  
  
  METHODS
  We used Cochrane's standard methodological procedures.
  
  
  RESULTS
  We included seven RCTs (2369 participants randomized) on the induction of pre-hospital cooling in comparison to in-hospital cooling. There was considerable methodological heterogeneity and risk of bias mainly due to deficits in the administration of cooling, therefore we refrained from pooling the results for survival and neurological outcome and we presented the results for each study separately. Adverse events were rare: based on four studies with 1713 adults pre-hospital induction of cooling may increase the risk of cardiac re-arrests. Risk of bias within the seven individual studies was generally moderate. Overall the quality of the evidence was very low. This was mainly driven by inconsistency and low precision.
  
  
  CONCLUSIONS
  Currently, there is no convincing evidence to clearly delineate beneficial or harmful effects of pre-hospital induction of cooling in comparison to in-hospital induction of cooling. This conclusion is based on very low quality evidence.
authors.affiliation: Department of Emergency Medicine, Medical University of Vienna, Währinger Gürtel 18-20 / 6D, Vienna, Austria, 1090.
authors.forename: Jasmin
authors.initials: J
authors.lastname: Arrich
authors.forename: Michael
authors.initials: M
authors.lastname: Holzer
authors.forename: Christof
authors.initials: C
authors.lastname: Havel
authors.forename: Alexandra-Maria
authors.initials: AM
authors.lastname: Warenits
authors.forename: Harald
authors.initials: H
authors.lastname: Herkner
mesh_terms: D000328:Adult; D000368:Aged; D016757:Death, Sudden, Cardiac; D004632:Emergency Medical Services / Q000379:methods*; D006801:Humans; D007036:Hypothermia, Induced / Q000009:adverse effects / Q000379:methods*; D002534:Hypoxia, Brain / Q000517:prevention & control*; D008875:Middle Aged; D000066829:Neuroprotection; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D012008:Recurrence; D012306:Risk