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Systematic review of randomized controlled trials of therapeutic hypothermia as a neuroprotectant in post cardiac arrest patients

Published online by Cambridge University Press:  21 May 2015

Ka Wai Cheung ,
Robert S. Green  and
Kirk D. Magee
Ka Wai Cheung
Affiliation:
Department of Emergency Medicine, Division of Critical Care Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, NS
Robert S. Green*
Affiliation:
Department of Emergency Medicine, Division of Critical Care Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, NS Department of Internal Medicine, Division of Critical Care Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, NS
Kirk D. Magee
Affiliation:
Department of Emergency Medicine, Division of Critical Care Medicine, Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, NS
*
Division of Critical Care, Queen Elizabeth II Health Sciences Centre, Dalhousie University, 1278 Tower Rd., Rm. 349, Bethune Building, Halifax NS B3H 2Y9

Abstract

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Objective:

Several randomized controlled trials have suggested that mild induced hypothermia may improve neurologic outcome in comatose cardiac arrest survivors. This systematic review of randomized controlled trials was designed to determine if mild induced hypothermia improves neurologic outcome, decreases mortality, or is associated with an increased incidence of adverse events.

Data sources:

The following databases were reviewed: Cochrane Controlled Trials Register (Issue 4, 2005), MEDLINE (January 1966 to November 2005), EMBASE (1980 to November 2005), CINAHL (1982 to November 2005) and Web of Science (1989 to November 2005). For each included study, references were reviewed and the primary author contacted to identify any additional studies.

Study selection:

Studies that met inclusion criteria were randomized controlled trials of adult patients (>18 years of age) with primary cardiac arrest who remained comatose after return of spontaneous circulation. Patients had to be randomized to mild induced hypothermia (32°C-34°C) or normothermia within 24 hours of presentation. Only studies reporting pre-determined outcomes including discharge neurologic outcome, mortality or significant treatment-related adverse events were included. There were no language or publication restrictions.

Data synthesis:

Four studies involving 436 patients, with 232 cooled to a core temperature of 32°C-34°C met inclusion criteria. Pooled data demonstrated that mild hypothermia decreased inhospital mortality (relative ratio [RR] 0.75; 95% confidence interval [CI], 0.62-0.92) and reduced the incidence of poor neurologic outcome (RR 0.74; 95% CI, 0.62-0.84). Numbers needed to treat were 7 patients to save 1 life, and 5 patients to improve neurologic outcome. There was no evidence of treatment-limiting side effects.

Conclusions:

Therapeutically induced mild hypothermia decreases in-hospital mortality and improves neurologic outcome in comatose cardiac arrest survivors. The possibility of treatment-limiting side effects cannot be excluded.

Keywords

cardiac arrestinduced hypothermiasystematic review
Type
Education • Éducation
Information
Canadian Journal of Emergency Medicine , Volume 8 , Issue 5 , September 2006 , pp. 329 - 337
Copyright
Copyright © Canadian Association of Emergency Physicians 2006

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