Quality of bystander cardiopulmonary resuscitation during real-life out-of-hospital cardiac arrest

Background: Cardiopulmonary resuscitation (CPR) can increase survival in out-of-hospital cardiac arrest (OHCA). However, little is known about bystander CPR quality in real-life OHCA. Aim: To describe bystander CPR quality based on automated external defibrillator (AED) CPR process data during OHCA and compare it with the European Resuscitation Council 2010 and 2015 Guidelines. Methods: We included OHCA cases from the Capital Region, Denmark, (2012-2016) where a Zoll AED was used before ambulance arrival. For cases with at least one minute of continuous data, the initial 10 min of CPR data were analysed for compression rate, depth, fraction and compressions delivered for each minute of CPR. Data are presented as median [25th; 75th percentile]. Results: We included 136 cases. Bystander median compression rate was 101 min(-1) [94; 113], compression depth was 4.8 cm [3.9; 5.8] and compressions per minute were 62 [48; 73]. Of all cases, the median compression rate was 100-120 min(-1) in 42%, compression depth was 5-6 cm in 26%, compression fraction >= 60% in 51% and compressions delivered per minute exceeded 60 in 54%. In a minute-to-minute analysis, we found no evidence of deterioration in CPR quality over time. The median peri-shock pause was 27 s [23; 31] and the pre-shock pause was 19 s [17; 22]. Conclusions: The median CPR performed by bystanders using AEDs with audio-feedback in OHCA was within guideline recommendations without deterioration over time. Compression depth had poorer quality compared with other parameters. To improve bystander CPR quality, focus should be on proper compression depth and minimizing pauses. (C) 2017 Elsevier B.V. All rights reserved.