Mechanical chest compression does not seem to improve outcome after out-of hospital cardiac arrest. A single center observational trial

Aim: Recently three large post product placement studies, comparing mechanical chest compression (cc) devices to those who received manual cc, found equivalent outcome results for both groups. Thus the question arises whether those results could be replicated using the devices on a daily routine. Methods: We prospectively enrolled 948 patients over a 12 months period. Chi-Square test and Mann-Whitney-U test were used to assess differences between manual and mechanical cc subgroups. Uni- and multivariate Cox regression hazard analysis were used to assess the influence of cc type on survival. Results: A mechanical cc device was used in 30.1% (n = 283) cases. Patients who received mechanical cc had a significantly worse neurological outcome - measured in cerebral performance category (CPC) than the manual cc group (56.8% vs. 78.6%, p = 0.009). Patients receiving mechanical cc were significantly younger, more were male and were more likely to have bystander CPR and an initially shock-able ECG rhythm. There was no difference in the quality of CPR that might explain the worse outcome in mechanical cc patients. Conclusion: Even with high quality CPR in both, manual and mechanical cc groups, outcome in patients who received mechanical cc was significantly worse. The anticipated benefits of a higher compression ratio and a steadier compression depth of a mechanical cc device remain uncertain. In this study selection for mechanical cc was not standardized, and was non-random. This merits further investigation. Further research on how mechanical cc is chosen and used should be considered. (C) 2015 Elsevier Ireland Ltd. All rights reserved.