Bystander-initiated chest compression-only CPR is better than standard CPR in out-of-hospital cardiac arrest

INTRODUCTION: Out-of-hospital cardiac arrest has a low survival rate to hospital discharge. Recent studies compared a simplified form of CPR, based on chest compression alone versus standard CPR including ventilation. We performed systematic review and meta-analysis of randomized controlled trials, focusing on survival at hospital discharge. METHODS: We extensively searched the published literature on out-of hospital CPR for non traumatic cardiac arrest in different databases. RESULTS: We identified only three randomized trials on this topic, including witnessed and not-witnessed cardiac arrests. When pooling them together with a meta-analytic approach, we found that there is already clinical and statistical evidence to support the superiority of the compression-only CPR in terms of survival at hospital discharge, as 211/1842 (11.5%) patients in the chest compression alone group versus 178/1895 (9.4%) in the standard CPR group were alive at hospital discharge: odds ratio from both Peto and DerSimonian-Laird methods =0.80 (95% confidence interval 0.65-0.99), p for effect =0.04, p for heterogeneity =0.69, inconsistency =0%). CONCLUSIONS: Available evidence strongly support the superiority of bystander compression-only CPR. Reasons for the best efficacy of chest compression-only CPR include a better willingness to start CPR by bystanders, the low quality of mouth-to-mouth ventilation and a detrimental effect of too long interruptions of chest compressions during ventilation. Based on our findings, compression-only CPR should be recommended as the preferred CPR technique performed by untrained bystander.