Hypothermia versus normothermia after out-of-hospital cardiac arrest: A systematic review and meta-analysis of randomized controlled trials. (February 2022)

• Record Type: Journal Article
• Authors: Shrestha, Dhan Bahadur; Sedhai, Yub Raj; Budhathoki, Pravash; Gaire, Suman; Adhikari, Anurag; Poudel, Ayusha; Aryal, Barun Babu; Yadullahi Mir, Wasey Ali; Dahal, Khagendra; Kashiouris, Markos G.
• Is Part Of: Annals of medicine and surgery. Volume 74(2022)
• Publication Date: 2022-02
• Subjects: Out-of-hospital cardiac arrest -- Temperature -- Induced Hypothermia; OHCA Out-of-hospital cardiac arrest -- TTM Targeted temperature management -- IHCA In-hospital cardiac arrest -- ROSC Return of spontaneous circulation -- PRISMA Preferred Reporting Items for Systematic Review and Meta-Analysis -- RCTs Randomized controlled trials -- TH Therapeutic hypothermia -- AHA American Heart Association -- ERC European resuscitation council -- OR Odds ratio -- CI Confidence interval; Surgery -- Periodicals; Medicine -- Periodicals; General Surgery -- Periodicals; Education, Medical -- Periodicals; Periodicals; 617
• DOI: 10.1016/j.amsu.2022.103327
• Languages: English
• ISSNs: 2049-0801

Abstract

Abstract: Background: The current guidelines recommend targeted temperature management (TTM) as part of the post-resuscitation care for comatose patients following out-of-hospital cardiac arrest. These recommendations are based on the weak evidence of benefit seen in the early clinical trials. Recent large multicentered trials have failed to show a meaningful clinical benefit of hypothermia, unlike the earlier studies. Thus, to fully appraise the available data, we sought to perform this systematic review and meta-analysis of randomized controlled trials. Methods: We searched four databases for randomized controlled trials comparing therapeutic hypothermia (32–34 °C) with normothermia (≥36 °C with control of fever) in adult patients resuscitated after out-of-hospital cardiac arrest. Independent reviewers did the title and abstract screening, full-text screening, and extraction. The primary outcome was mortality six months after cardiac arrest, and secondary outcomes were neurological outcomes and adverse effects. Relevance for patients: Six randomized controlled trials were included in this review. There was no significant difference between the hypothermia and normothermia groups in mortality till 6 months follow up after out-of-hospital cardiac arrest (OR 0.88, 95% CI 0.67–1.16; n = 3243; I 2 = 51%), or favorable neurological outcome (OR 1.31, 95% CI 0.93–1.84; n = 3091; I 2 = 68%). Rates of arrhythmias were notably higher in the hypothermia group than the normothermia group (OR 1.43, 95% CI 1.20–1.71; n = 3029; I 2 = 4%). However, odds for development of pneumonia showed no significant differences across two groups (OR 1.13, 95% CI 0.98–1.31; n = 3056; I 2 = 22%). Therefore, targeted hypothermia with a target temperature of 32–34 °C does not provide mortality benefit or better neurological outcome in patients resuscitated after the out-of-hospital cardiac arrest when compared with normothermia. Highlights: Targeted hypothermia as part of the post-resuscitation care did not reduce mortality after OHCA. There was no difference in neurological outcome between hypothermia and normothermia groups. A higher incidence of arrhythmias was seen in the hypothermia group.