Therapeutic benefits of mild hypothermia in patients successfully resuscitated from cardiac arrest: A meta-analysis.

BACKGROUND Good neurological outcome after cardiac arrest (CA) is hard to achieve for clinicians. Experimental and clinical evidence suggests that therapeutic mild hypothermia is beneficial. This study aimed to assess the effectiveness and safety of therapeutic mild hypothermia in patients successfully resuscitated from CA using a meta-analysis. METHODS We searched the MEDLINE (1966 to April 2012), OVID (1980 to April 2012), EMBASE (1980 to April 2012), Chinese bio-medical literature & retrieval system (CBM) (1978 to April 2012), Chinese medical current contents (CMCC) (1995 to April 2012), and Chinese medical academic conference (CMAC) (1994 to April 2012). Studies were included if 1) the study design was a randomized controlled trial (RCT); 2) the study population included patients successfully resuscitated from CA, and received either standard post-resuscitation care with normothermia or mild hypothermia; 3) the study provided data on good neurologic outcome and survival to hospital discharge. Relative risk (RR) and 95% confidence interval (CI) were used to pool the effect. RESULTS The study included four RCTs with a total of 417 patients successfully resuscitated from CA. Compared to standard post-resuscitation care with normothermia, patients in the hypothermia group were more likely to have good neurologic outcome (RR=1.43, 95% CI 1.14-1.80, P=0.002) and were more likely to survive to hospital discharge (RR=1.32, 95% CI 1.08-1.63, P=0.008). There was no significant difference in adverse events between the normothermia and hypothermia groups (P>0.05), nor heterogeneity and publication bias. CONCLUSION Therapeutic mild hypothermia improves neurologic outcome and survival in patients successfully resuscitated from CA.