Purpose of the study:
Time delay to CPR and first defibrillation has been shown to decrease survival from cardiac arrest caused by ventricular fibrillation (1). Survival from layperson witnessed PEA however has not been shown to have a similar time dependent correlation (2). We wanted to investigate whether emergency medical services (EMS) witnessed PEA has a survival benefit compared to layperson witnessed PEA in out-of-hospital cardiac arrest (OHCA).
Materials and methods:
We performed a retrospective observational study from the OHCA registry of Helsinki, Finland. All layperson and EMS witnessed cardiac arrests with PEA as the initial rhythm were included from 1.1.1997 to 31.12.2017. Survival from the hospital was the primary end point for the study.
During the study period, 7475 OHCAs occurred. Resuscitation was attempted in 5028 cases (67,3 %). There were 1054 layperson witnessed and 523 EMS witnessed resuscitation attempts with PEA as the initial rhythm. 61 EMS witnessed PEA patients (11,7 %) survived from the hospital compared to 91 (8,6 %) layperson witnessed PEA patients (p=0,057). Survival with good neurological outcome (cerebral performance category score of 1 or 2) was only moderately higher in EMS witnessed PEA (9,9 %) compared to layperson witnessed PEA (6,3 %) with statistical significance (p=0,011). There was no difference in one-year survival (EMS witnessed 9,8 %, layperson witnessed 7,1 %, p=0,076).
Immediate resuscitation by EMS personnel in EMS witnessed PEA seems to offer only modest survival benefit compared to layperson witnessed PEA in OHCA.