The aim of this study was to analyse a large CPR database, the German Resuscitation Registry, to evaluate potential benefits of mechanical CPR devices over manual CPR in adult cardiac arrest victims. The primary endpoint considered is ROSC.

In a retrospective analysis of the German Resuscitation Registry between 2007-2014, investigators examined the outcome after using mechanical CPR on return of spontaneous circulation (ROSC) in adults with out-of-hospital cardiac arrest (OHCA). Investigators compared mechanical CPR (Intervention group) to manual CPR (control group). According to preclinical risk factors, investigators calculated the predicted ROSC-after-cardiac-arrest (RACA) score for each group, and compared it to the rate of ROSC observed. Using multivariate analysis, investigators adjusted the influence of the devices' application on ROSC for epidemiological factors and therapeutic measures.

Inclusion Criteria:

• out of hospital cardiac arrest
• during time prod from January 2007 until December 2014
• CPR attempted

Exclusion Criteria:

• Investigators excluded cases in which CPR was continued for less than five minutes, or duration of CPR was missing, as the outcome in this early period is not affected by the CPR mode.
• Children aged less than 18 years and patients of unknown age were also excluded as the devices are not approved for resuscitation on children.
• An active compression-decompression (ACD) is a hand-held suction device, to compress and actively decompress the chest after each compression.
• Investigators also excluded cases where ACD CPR was used, because it constitutes a different technology.
• Cases due to trauma were excluded as application of mechanical CPR devices may be limited due in traumatic events.
• Cases where data on ROSC and/or CPR mode was missing were also excluded.

Patient suffering OHCA and be resuscitated by EMS where the data were delivered to the German Resuscitation Registry