Out-of-hospital cardiac arrest phone detection: those who most need chest compressions are the most difficult to recognize

Dispatcher-assisted cardiopulmonary resuscitation increases the likelihood of survival and thus is highly recommended. However, the detection rate of out-of-hospital cardiac arrest (OHCA) is very different from one system to another, and early recognition of cardiac arrest in the dispatch centre remains challenging. The aim of this study was to assess the provision of dispatcher-assisted cardiopulmonary resuscitation in the main French dispatch centre.

Methods: In the Paris Fire Brigade, each patient over 15 years of age who presented an OHCA from 15 to 31 May 2012 was prospectively included. Field data and tape recordings of emergency calls were studied by three experienced physicians, to assess the rate (and delay) of OHCA recognition and chest compression initiation, and identify the causes of unrecognized OHCA.

Results: Among 82 consecutive calls for detectable cardiac arrest, the dispatcher recognized 50/82 (61%). The median times from call to OHCA recognition and from call to chest compression initiation were, respectively, 2 min 23s (1 min 51 s to 3 min 7s) and 3 min 37s (2 min 57 s to 5 min). The main causes of non-recognition of OHCA were the absence or incomplete assessment of breathing and the presence of agonal breathing. No cardiac arrest was missed when the dispatcher followed the local dispatch algorithm; this included the gesture of putting the hand on the abdomen and measuring the breathing frequency. Hospital admission with a beating heart was paradoxically 18% for detected cardiac arrest and 47% for undetected cardiac arrest (p=0.007). This paradox could be explained by the relation between agonal breathing and, on the one hand, good prognosis of OHCA and, on the other hand, difficulties in recognizing OHCA.

Conclusion: The improvement of cardiac arrest recognition in the dispatch centre seemed mandatory, as the cardiac arrests of better immediate prognosis were not well detected. The measurement of OHCA recognition and CPR initiation by phone should be encouraged in dispatch centres as a key to initiating corrective measures.