Improving emergency call detection of Out-of-Hospital Cardiac Arrests in the Greater Paris area: Efficiency of a global system with a new method of detection.

Aim: The detection of cardiac arrests by dispatchers allows telephone-assisted cardiopulmonary resuscitation (t-CPR) and improves Out-of-Hospital Cardiac Arrest (OHCA) survival. To enhance the OHCA detection rate, in 2012, the Paris Fire Brigade dispatch center created an original technique called "Hand On Belly" (HoB). The new algorithm that resulted has become a central point in a broader program for dispatch-assisted cardiac arrests.

Methods: This is a repeated cross-sectional study with retrospective data of four 15-day call samples recorded from 2012 to 2018. We included all calls from OHCAs cared for by Basic Life Support (BLS) teams and excluded calls where the dispatcher was not in contact directly with a witness. The primary endpoint was the successful detection of an OHCA by the dispatcher; the secondary endpoints were successful t-CPR and measurements of the different time intervals related to the call. Logistic regressions were performed to assess parameters associated with detecting OHCAs and initiating t-CPR.

Results: From 2012 to 2018, among the detectable OCHAs, the proportion correctly identified increased from 54% to 93%; the rate of t-CPRs from 51% to 84%. OHCA detection and t-CPR initiation were both associated with HoB breathing assessments (adjustedOR: 89, 95%CI: 31-299, and adjustedOR: 11.2, 95%CI: 1.4-149, respectively). Over the study period, the times to answering calls and the time to sending BLS teams were shorter than those recommended by international guidelines; however, the times to OHCA recognition and starting t-CPR delivery were longer.

Conclusions: The HoB effectively facilitated OHCA detection in our system, which has achieved very high performance levels.