Safety profile and outcome of mild therapeutic hypothermia in patients following cardiac arrest: systematic review and meta-analysis

Evidence has shown that mild therapeutic hypothermia (MTH) could improve survival and neurological outcome in patients following cardiac arrest. But this therapy may cause some adverse effects. The authors sought to take a systematic approach to describe the safety aspects and outcome of MTH following cardiac arrest to help clinical practice. MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, BIOSIS Previews and clinicaltrials.gov were searched up to June 2011. Bibliographies of relevant studies were also reviewed. Comparative studies reporting the mortality or any other studies reporting any kind of adverse events in patients undergoing MTH after cardiac arrest and published in English were included. Of 1742 abstracts, 63 studies were included. Most adverse events potentially associated with therapeutic hypothermia were not significantly different between the hypothermia therapy and the normothermia groups. No significant difference was found in the inhospital mortality, bleeding, pneumonia and bradycardia events between surface and endovascular-cooled groups in this study. Cooling device-related adverse events were generally mild. Serious adverse events potentially attributable to therapeutic hypothermia were seldom reported. MTH was associated with reduced inhospital mortality, mortality at 1 month and at 6 months. Evidence about the safety of MTH in children has been limited. These results suggest that while it may result in some adverse events, MTH is generally safe in patients following cardiac arrest and could improve the short-term and long-term survival of comatose patients after cardiac arrest. But awareness of these adverse events should be kept in mind in clinical practice.