Therapeutic hypothermia after cardiac arrest is not associated with favorable neurological outcome: a meta-analysis

Abstract

Background: Cardiac arrest is associated with very high mortality and causes neurological dysfunction in the survivors. Therapeutic hypothermia is one of the recommended modality in the postarrest management. However, recent findings question its benefit in postarrest management. This meta-analysis has been conceptualized to quantify clinical benefit of therapeutic hypothermia in post-cardiac arrest patients.

Methods: Prospective, randomized, and quasi-randomized controlled trials comparing the efficacy of therapeutic hypothermia in post-cardiac arrest adult population with a post-cardiac arrest management protocol that does not include therapeutic hypothermia were included in this meta-analysis. Two authors independently searched PubMed, PubMed Central, Scopus, and Central Register of Clinical Trials of the Cochrane Collaboration for potentially eligible trials.

Results: Data of 1399 patients from 6 controlled trials have been included in this systematic review and meta-analysis. Therapeutic hypothermia does not provide any benefit in favorable neurological outcome (P=.06; odds ratio, 1.80; 95% confidence interval [CI], 0.97-3.35; n=1384), in survival at hospital discharge (P=.58; odds ratio, 1.16; 95% CI, 0.69-1.96; n=1399), and in long-term survival (P=.36; odds ratio, 1.32; 95% CI, 0.73-2.39; n=1292). Therapeutic hypothermia also increases incidence of pneumonia (P=.02; odds ratio, 1.30; 95% CI, 1.04-1.64; n=1204; number needed to harm, 15).

Conclusion: Therapeutic hypothermia in the post-cardiac arrest management protocol does not provide any benefit in favorable neurological outcome, survival to hospital discharge, and long term survival. Incidence of pneumonia may be increased with the use of therapeutic hypothermia.

Keywords: Favorable neurological outcome; Hypothermia; Post–cardiac arrest; Therapeutic hypothermia.