Abstract 46: Guidelines Changes and Improvement of Survival to Hospital Discharge After Out-of-Hospital Cardiac Arrest: A Meta-Analysis from the Literature

Abstract

Introduction. Every year 350.000 to 750.000 cases of cardiac arrest occur in the US and in Europe. Since 1974 seven editions of CPR-ECC guidelines have been published and many aspects have been changed. In particular more and more empahis has been given on CPR and the suggested compression to ventilation ratio has progressively been increased (5:1 before 2000, 15:2 from 2000 to 2005 and 30:2 after 2005). The aim of our study is to evaluate, based on a review of the literature, the impact of changes in guidelines on survival to hospital discharge after out of hospital cardiac arrest (OHCA). Material and methods. We searched PubMed for studies on “survival to hospital discharge after OHCA”. Mandatory inclusion criteria included the report of survival to hospital discharge in all patients regardless of presenting rhythm. All data were analyzed according to the year of inclusion: group 1 before 2000; group 2 between 2000 and 2005 and group 3 after 2005. Survival/mortality rates were computed for each group, together with their 95% binomial confidence interval (95%CI). In-hospital mortality rates were compared between groups by means of a group frequency weighted log linear model. Risk ratios (RR) and 95%CI were reported. Results. Among 558 studies retrieved, 45 met our inclusion criteria, with a total of 119,111 of OHCA patients evaluable (65,601 in group 1; 35,954 in group 2 and 17,556 in group 3). The mean call to response time was similar in the three groups: 7.9 ± 2.7 min,; 7.5 ± 2.3 min and 6.9 ± 2.0. min in group 1, 2 and 3, respectively. Survival to hospital discharge in the 3 groups was 6.2% (95%CI 6.0-6.4), 6.4% (95%CI 6.2-6.7) and 9.9% (95%CI 9.5-10.4), respectively (log linear model p<0.001). Specifically a significant decrease in risk of hospital death was observed in group 3 vs group 2 (RR 0.69 (95%CI 0.95-0.97, p<0.001), but not in group 2 vs group 1 (RR 1.00 (0.99-1.00, p=0.14). Conclusion. This quantitative review of the literature demonstrated that survival to hospital discharge after OHCA has significantly increased after 2005 guidelines changes. The cardio-centric revolution in CPR and in advanced care with more high quality CPR resulted in a 30% improvement in survival after OHCA.