The impact of a high-quality basic life support police-based first responder system on outcome after out-of-hospital cardiac arrest

Background Laypersons' efforts to initiate basic life support (BLS) in witnessed Out-of-Hospital Cardiac Arrest (OHCA) remain comparably low within western society. Therefore, in order to shorten no-flow times in cardiac arrest, several police-based first responder systems equipped with automated external defibrillators (Pol-AED) were established in urban areas, which subsequently allow early BLS and AED administration by police officers. However, data on the quality of BLS and AED use in such a system and its impact on patient outcome remain scarce and inconclusive. Methods A total of 85 Pol-AED cases were randomly assigned to a gender, age and first rhythm matched non-Pol-AED control group (n = 170) in a 1:2 ratio. Data on quality of BLS were extracted via trans-thoracic impedance tracings of used AED devices. Results Comparing Pol-AED cases and the control group, we observed a similar compression rate per minute (p = 0.677) and compression ratio (p = 0.651), mirroring an overall high quality of BLS administered by police officers. Time to the first shock was significantly shorter in Pol-AED cases (6 minutes [IQR: 2–10] vs. 12 minutes [IQR: 8–17]; p<0.001). While Pol-AED was not associated with increased sustained return of spontaneous circulation (p = 0.564), a strong and independent impact on survival until hospital discharge (adj. OR: 1.85 [95%CI: 1.06–3.23; p = 0.030]) and a borderline significance for the association with favorable neurological outcome (adj. OR: 1.58 [95%CI: 0.96–2.89; p = 0.052) were observed. Conclusion We were able to demonstrate an early start and a high quality of BLS and AED use in Pol-AED assessed OHCA cases. Moreover, the presence of Pol-AED care was associated with better patient survival and borderline significance for favorable neurological outcome.