ROSC after cardiac arrest--the RACA score to predict outcome after out-of-hospital cardiac arrest.

Aims: Return of spontaneous circulation (ROSC) following cardiopulmonary resuscitation from cardiac arrest (CA) depends on numerous variables. The aim of this study was to develop a score to predict the initial resuscitation outcome-the RACA (ROSC after cardiac arrest) score.

Methods And Results: Based on 5471 prospectively registered out-of-hospital CAs patients between 1998 and 2008 within the German Resuscitation Registry, calculation of the RACA score was performed by multivariate logistic regression analysis with ROSC as the outcome variable. The probability of ROSC was defined as 1/(1 + e(-X)), where X is the weighted sum of independent factors. Additional 2218 patients documented between 2009 and 2010 were used for validation of the RACA score. The following independent variables were found to have a significant positive (+) or negative (-) impact on the probability of ROSC: male gender (-0.2); age ≥80 years (-0.2); witnessing by lay people (+0.6) and by professionals (+0.5); asystole (-1.1); location at doctor's office (+1.2), medical institution (+0.5), public place (+0.3) and nursing home (-0.3); presumable aetiology of hypoxia (+0.7), intoxication (+0.5) and trauma (-0.6); and time until professionals arrival (-0.04 per minute). In a validation cohort, observed ROSC (43.8%) did not differ from predicted ROSC (43.7%).

Conclusion: The RACA score represents a simple tool and enables comparison between observed and predicted ROSC rates based on readily available variables after CA. Thereby, the RACA score may contribute to preclinical quality assessment and may help analysing the effects of different (post)-resuscitation strategies.