Author: Stephen D Haig / Editor: Adrian Boyle / Reviewer: Michael Stewart / Codes: ACCS LO 2, EnvC3, RP3, SLO10, SLO3 / Published: 05/12/2018


  • Systematic review of randomised and non-randomised trials of therapeutic hypothermia for non-shockable cardiac arrest
  • Patients – non-shockable cardiac arrest, adults
  • Intervention – Therapeutic hypothermia
  • Comparator – standard care/normothermia
  • Outcomes – survival to hospital discharge, favourable neurological outcome
  • Study type – randomised trials, and non-randomised studies
  • Searches of EMBASE, PubMed, CENTRAL, and BIOSIS until March 2010. No language limit.
  • 2 investigators independently assessed papers for inclusion
  • Analysis performed separately for randomised and non-randomised trials.
  • Results: 8416 citations identified. 2 randomised trials were included, and 12 observational cohort studies.
  • The RCTs were combined in an analysis of survival to discharge; no significant statistical heterogeneity was demonstrated (I2=0%). No significant benefit was found (RR 0.85 95% CI 0.65, 1.11)
  • The non-randomised trials were combined for both survival to discharge and for neurological outcome. Survival to discharge was statistically significant (RR 0.84 CI 0.78, 0.92), with little heterogeneity (I2=0%). And, for neurological outcome it was borderline significant (RR 0.93 CIs 0.88, 1.00), and little heterogeneity (I2=0%).
  • Internal validity of the trials was assessed and was found to be generally low.
  • Conclusion was that there was some justification for using therapeutic hypothermia in non-shockable cardiac arrest.

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