Osnabrück Study on Cardiac Arrest: A prospective trial on the introduction of a real-time feedback system in out-of-hospital resuscitation

Purpose: The prospective cohort study “OSCAR” analyses the possible changes in chest compression quality by introducing a real-time feedback system (device: corpuls® C3 with corPatch CPR) and thus evaluating depth, frequency and pauses in compression in three phases.1 So far during this ongoing study, some challenges regarding patient-recruitment, data collection and data analysis appeared and solutions had to be found. Methods: In phase 1, resuscitation was performed without a feedback sensor. In phase 2, the sensor, placed on patient's sternum, was used to measure the depth of compression without giving feedback, while in phase 3 the emergency medical service staff received real-time feedback. Depth of compression is analysed on the basis of feedbacksensor-data. Frequency of compression and pauses of compression are analysed by compression-artefacts in the ECG. The soft-ware “CPRAnalysis” (GS Elektromedizinische Geräte, Kaufering, Germany) was developed to analyse the data and is first being used in this study. The implementation of feedback sensor-usage has been a major challenge: Motivation of the rescue service staff to use the sensor was enhanced in various ways like posters, newspaper articles and presentations. Results: In phase 1, the required patients were included within 134 days, in phase 2, it took 322 days to include the patients needed. The feedback sensor was used in 54% of all cases and in median 133 s passed until the sensor was applied. Conclusion: Introducing the feedback sensor in a rare, timecritical and challenging situation like resuscitation [1] needs extraordinary multi-layered motivation work. Nevertheless the sensor was used in only 54% of the cases in phase 2 and additionally a delayed application of the sensor was detected in some cases. Therefore the feedback electrode integrated in the defibrillation electrode seems to offer an advantage compared to the separate electrode. The trial is ongoing and has currently reached its final phase [2].