The effect of bystander cardiopulmonary resuscitation on the survival of out-of-hospital cardiac arrests: a systematic review and meta-analysis

Background: For many years, bystander cardiopulmonary resuscitation (BCPR) has been considered as a favorable factor to improve survival of out-of-hospital cardiac arrests (OHCAs). To examine the effect of BCPR on the survival of OHCAs and whether BCPR might also improve survival when the initial rhythm of OHCAs is limited, we performed a meta-analysis on published observational studies. Methods: We did a systematic review to identify all studies published up to March, 2018, in any language, that reported the relation between BCPR and the survival of OHCAs. Using standard forms, two authors independently identified studies for inclusion and extracted information. The outcome was survival. Meta-regression was done to ascertain weighted factors for the outcomes. Results: Data were extracted from 19 studies involving 232,703 patients. Firstly, pooled odds ratio (OR) from 16 cohort studies showed that BCPR was associated with improved chance of survival of OHCAs compared with NO-BCPR (OR 1.95, 95% confidence interval [CI]: 1.66-2.30). Secondly, from 8 cohort studies of OHCAs whose initial rhythm is limited, the pooled OR was 2.10 (95% CI, 1.68-2.63) of 6 articles for shockable rhythm and 1.07 (95% CI, 0.37-3.13) of 2 articles for non-shockable rhythm. Meta-regression showed a relation between the survival of OHCAs and BCPR was influenced by area (p < 0.05). Conclusions: Based on currently available evidence, the findings of this meta-analysis suggest that BCPR increases the survival of OHCAs, and it also help OHCAs whose initial rhythm is shockable. That is to say BCPR is also helpful when emergency department response time is short. Therefore global priority should be given to increasing the incidence of BCPR by evidence-based best practice.