Background: Cardiac arrest is an event with a limited prognosis which has not substantially changed since the first description of cardiopulmonary resuscitation (CPR) in 1960. A promising new treatment approach may be mechanical CPR devices (mechanical CPR).
Methods: In a retrospective analysis of the German Resuscitation Registry between 2007-2014, we examined the outcome after using mechanical CPR on return of spontaneous circulation (ROSC) in adults with out-of-hospital cardiac arrest (OHCA). We compared mechanical CPR to manual CPR. According to preclinical risk factors, we calculated the predicted ROSC-after-cardiac-arrest (RACA) score for each group and compared it to the rate of ROSC observed. Using multivariate analysis, we adjusted the influence of the devices' application on ROSC for epidemiological factors and therapeutic measures.
Results: We included 19,609 patients in the study. ROSC was achieved in 51.5% of the mechanical CPR group (95%-CI 48.2-54.8%, ROSC expected 42.5%) and in 41.2% in the manual CPR group (95%-CI 40.4-41.9%, ROSC expected 39.2%). After multivariate adjustment, mechanical CPR was found to be an independent predictor of ROSC (OR 1.77; 95%-CI 1.48-2.12). Duration of CPR is a key determinant for achieving ROSC.
Conclusions: Mechanical CPR was associated with an increased rate of ROSC and when adjusted for risk factors appeared advantageous over manual CPR. Mechanical CPR devices may increase survival and should be considered in particular circumstances according to a physicians' decision, especially during prolonged resuscitation.