Effect of post-rewarming fever after targeted temperature management in cardiac arrest patients: a systematic review and meta-analysis

BACKGROUND:Targeted temperature management （TTM）,as a therapeutic temperature control strategy for cardiac arrest （CA）,is recommended by guidelines.However,the relationship between postrewarming fever （PRF） and the prognosis of CA patients is unclear.Therefore,we aim to summarize the studies regarding the influence of PRF on patients with CA.METHODS:EMBASE,PubMed,and Cochrane Central databases were searched from inception to March 13,2022.Randomized clinical trials （RCTs） and cohort studies on PRF in CA patients were included.According to the heterogeneity,the meta-analysis was performed using a random effects model or fixed effects model to calculate the pooled odds ratios （ORs） and corresponding 95%confidence intervals （CIs）.The outcome data were unfavorable neurological outcome and mortality.RESULTS:The meta-analysis included 11 observational studies involving 3,246 patients.The results of the meta-analysis show that PRF （body temperature>38.0°C） has no effect on the neurological outcome of CA patients （OR 0.71,95%CI 0.43–1.17,I2 82%） and has a significant relationship with lower mortality （OR 0.63;95%CI 0.49–0.80,I2 39%）.However,PRF with a stricter definition （body temperature>38.5°C） was associated with worse neurological outcome （OR 1.44,95%CI 1.08–1.92,I2 45%） and higher mortality （OR 1.71,95%CI 1.25–2.35,I2 47%）.CONCLUSION:This study suggests that PRF>38.0°C may not affect the neurological outcome and have a lower mortality in CA patients who completed TTM.However,PRF>38.5°C is a potential prognostic factor for worse outcomes in CA patients.