title: Therapeutic hypothermia after cardiac arrest: A systematic review/meta-analysis exploring the impact of expanded criteria and targeted temperature.
abstract: We aimed to determine the benefit of an expanded use of TH. We also described the impact of a targeted temperature management on outcomes at discharge.
  
  
  
  We identified studies by searching MEDLINE, EMBASE and Cochrane Library databases. We included RCTs and observational studies restricted to those reporting achieved temperature during TH after OHCA. No other patient, cardiac arrest or hypothermia protocol restrictions were applied. Outcomes of interest were hospital mortality and neurological outcome at discharge. Appropriate risk of bias assessment for meta-analyzed studies was conducted. Studies contrasting hypothermia and normothermia outcomes were meta-analyzed using a random-effect model. Outcomes of cooling arms, obtained from enrolled studies, were pooled and compared across achieved temperatures.
  
  
  
  Search strategy yielded 32,275 citations of which 24 articles met inclusion criteria. Eleven studies were meta-analyzed. The use of TH after OHCA, even within an expanded use, decreased the mortality (OR 0.51, 95%CI [0.41-0.64]) and improved the odds of good neurological outcome (OR 2.48, 95%CI [1.91-3.22]). No statistical heterogeneity was found for either mortality (I2=4.0%) or neurological outcome (I2=0.0%). No differences in hospital mortality (p=0.86) or neurological outcomes at discharge (p=0.32) were found when pooled outcomes of 34 hypothermia arms grouped by cooling temperature were compared.
  
  
  
  The use of TH after OHCA is associated with a survival and neuroprotective benefit, even when including patients with non-shockable rhythms, more lenient downtimes, unwitnessed arrest and/or persistent shock. We found no evidence to support one specific temperature over another during hypothermia.
authors: Internal Medicine, Cleveland Clinic, OH, USA. Electronic address: schenoa@ccf.org.
authors: Aldo L
authors: AL
authors: Schenone
authors: Internal Medicine, Cleveland Clinic, OH, USA.
authors: Aaron
authors: A
authors: Cohen
authors: Nephrology Department, University Hospital Case Western Reserve University, OH, USA.
authors: Gabriel
authors: G
authors: Patarroyo
authors: Internal Medicine, Cleveland Clinic, OH, USA.
authors: Logan
authors: L
authors: Harper
authors: Department of Quantitative Health Sciences, Cleveland Clinic, OH, USA.
authors: XiaoFeng
authors: X
authors: Wang
authors: Cardiology Department, Cleveland Clinic, Cleveland, OH, USA.
authors: Mehdi H
authors: MH
authors: Shishehbor
authors: Cardiology Department, Cleveland Clinic, Cleveland, OH, USA.
authors: Venu
authors: V
authors: Menon
authors: Pulmonary and Critical Care Department, Cleveland Clinic, Cleveland, OH, USA.
authors: Abhijit
authors: A
authors: Duggal
mesh_terms: D001831:Body Temperature; D016887:Cardiopulmonary Resuscitation; D006750:Hospital Distribution Systems / Q000706:statistics & numerical data; D017052:Hospital Mortality; D006801:Humans; D007036:Hypothermia, Induced / Q000401:mortality* / Q000706:statistics & numerical data; D064887:Observational Studies as Topic; D058687:Out-of-Hospital Cardiac Arrest / Q000401:mortality* / Q000628:therapy*; D016032:Randomized Controlled Trials as Topic; D016896:Treatment Outcome
keywords: Expanded hypothermia use; Out-hospital cardiac arrest; Targeted temperature management; Therapeutic hypothermia