Clinical Effect of Post-rewarming Fever after Targeted Temperature Management in Cardiac Arrest Patients: A Systematic Review and Meta-Analysis

Aim: To characterize and summarize the studies regarding the influence of post-rewarming fever on neurological outcome and mortality in cardiac arrest patients. Methods: : Two investigators separately screened relevant articles in EMBASE, PubMed, and Cochrane Central databases. Randomized clinical trials (RCTs) and cohort studies that evaluated the influence of post-rewarming fever (PRF) and normothermia in cardiac arrest patients were included. The meta-analysis was performed using a random effects model or a fixed effects model to calculate the pooled odds ratios (ORs) and corresponding 95% confidence intervals (CIs). The primary outcome was the unfavorable neurological outcome and the secondary outcome was the mortality. Results: : The meta-analysis included 12 studies involving 2,991 patients. Results of quantitative analysis suggested that PRF (body temperature >37.5°C) did not affect the unfavorable neurological outcome of patients with cardiac arrest (OR, 0.82; 95% CI, 0.54-1.25; I 2 , 81%). Also, PRF (body temperature >37.8°C) was not related to higher mortality of patients with cardiac arrest (OR, 0.86; 95% CI, 0.55-1.34; I 2 , 74%). However, PRF with higher body temperature (>38.5℃) was associated with higher mortality (OR, 2.22; 95%CI, 1.40- 3.35; I 2 , 0%). Conclusions: : This study suggests that PRF (body temperature >37.5°C) is not related to neurological outcome. And no significant association is found between PRF (body temperature >37.8°C) and mortality. However, PRF is associated with higher mortality when PRF was defined as >38.5℃.