The impact of response time reliability on CPR incidence and resuscitation success: a benchmark study from the German Resuscitation Registry.

INTRODUCTION

Sudden cardiac arrest is one of the most frequent causes of death in the world. In highly qualified emergency medical service (EMS) systems, including well trained emergency physicians, spontaneous circulation may be restored in up to 53% of patients at least until admission to hospital. Compared with these highly qualified EMS systems, in other systems markedly lower success rates are observed. These data clearly show that there are considerable differences between EMS systems concerning treatment success following cardiac arrest and resuscitation, although in all systems international guidelines for resuscitation are used. This study investigates the impact of response time reliability (RTR) on cardio pulmonary resuscitation (CPR) incidence and resuscitation success using return of spontaneous circulation (ROSC) after cardiac arrest (RACA) score and data from seven German EMS systems participating in the German Resuscitation Registry.

METHODS

Anonymized patient data after out of hospital cardiac arrest from 2006 to 2009 of seven EMS systems in Germany were analysed to socioeconomic factors (population, area, EMS unit hours), process quality (response time reliability, CPR incidence, special CPR measures, prehospital cooling), patient factors (age, gender, cause of cardiac arrest, bystander CPR). Endpoints were defined as ROSC, admission to hospital, 24 hour survival and hospital discharge rate. For statistical analyses, chi-square, odds-ratio and Bonferroni correction were used.

RESULTS

2,330 prehospital CPR from seven centres were included in this analysis. Incidence of sudden cardiac arrest differs from 36.0 to 65.1/100,000 inhabitants/year. We identified two EMS systems (RTR < 70%) reaching the patients within eight minutes in 62.0% and 65.6% while the other five EMS systems (RTR > 70%) achieved 70.4 up to 95.5%. EMS systems arriving relatively later at the patients side (RTR < 70%) less frequently initiate CPR and admit fewer patients alive to hospital (calculated per 100,000 inhabitants/year) (CPR incidence (1/100,000 inhabitants/year) RTR > 70% = 57.2 vs RTR < 70% = 36.1, OR = 1.586 (99% CI = 1.383 to 1.819); P < 0.01) (admitted to hospital with ROSC (1/100,000 inhabitants/year) RTR > 70% = 24.4 vs RTR < 70% = 15.6, OR = 1.57 (99% CI = 1.274 to 1.935); P < 0.01). Using ROSC rate and the multivariate RACA score to predict outcome, the two groups did not differ, but ROSC rates were higher than predicted in both groups (ROSC RTR > 70% = 46.6% vs RTR < 70% = 47.3%, OR = 0.971 (95% CI = 0.787 to 1.196); P = n.s.) (ROSC RACA RTR > 70% = 42.4% vs RTR < 70% = 39.5%, OR = 1.127 (95% CI = 0.911 to 1.395); P = n.s.).

CONCLUSION

This study demonstrates that on the level of EMS systems, faster ones will more often initiate CPR and will increase number of patients admitted to hospital alive. Furthermore it is shown that with very different approaches, all adhering to and intensely training in the ERC guidelines 2005, superior and, according to international comparison, excellent success rates following resuscitation may be achieved.