Effectiveness of therapeutic hypothermia on neurological status and survival in patients after cardiac arrest: a Meta-analysis

Objective To evaluate the effects of therapeutic hypothermia on both neurological status and survival rate in patients after cardiac arrest. Methods The data were searched from MEDLINE, PubMed, EMBASE, Cochrane Library, Wanfang database, CNKI and CBM. The randomized and controlled trials were selected for evaluating the main outcomes of neurological status and survival rate in patients after cardiac arrest. Meta-analysis was carried out by using Review Manger 5.0 software. The results were expressed in risk ratio (RR) for dichotomous outcomes data with 95% confidence intervals (CI) , and P < 0.05 was considered to be significant. Results Eight randomized controlled clinical trials with a total of 1 512 patients met our inclusion criteria. The overall risk ratio of favorable neurological status was 1.34 (95% CI: 1.01 -1.78, P 0.05) with therapeutic hypothermia compared with controls, however, when the applications of conventional cooling trials were analyzed, the risk ratio was 1.51 (95% CI: 1.22-1.87, P <0.01) and 1.36 (95% CI: 1.13-1.63, P <0.01) , respectively. Conclusions Patients treated with therapeutic hypothermia after cardiac arrest had more favorable neurological status compared with the controls. There was no benefit of therapeutic hypothermia to survival rate identified. Compare with conventional cooling methods, the therapeutic hypothermia could improve neurological status and survival rate in patients after cardiac arrest. Key words: Therapeutic hypothermia; Cardiac arrest; Neurological status; Survival; Meta-analysis