Public access defibrillation in out-of-hospital cardiac arrest: low utilization (22%) but improved survival in a spanish cohort

Out-of-hospital cardiac arrest (OHCA) affects approximately 350,000 adults annually in Europe, with survival to hospital discharge of 10-12%. Early defibrillation using automated external defibrillators (AEDs) is key in the chain of survival of (OHCA), as one of its first links. However, in Spain, AED availability and deployment remain limited and heterogeneous across regions, in contrast to other European countries.

To analyze the use of the AED in the region of Castilla-La Mancha and its relationship with in-hospital mortality and neurological prognosis in patients with recovered OHCA, in a retrospective cohort of a tertiary hospital between 2009 and 2024.

Retrospective observational study of patients admitted after OHCA with an initial shockable rhythm. Clinical variables, characteristics of the event and evolution were analyzed. Neurological prognosis was assessed with the CPC scale (1–2 = good prognosis). Student's t or Fisher's exact test were applied depending on the type of variable.

A total of 80 patients with OHCA and initial shockable rhythm were included, 23.7% of whom were resuscitated by lay witnesses. 21.6% of patients with OHCA and initial DF rhythm were resuscitated with AED; The mean age was similar (61.1 ± 13.2 vs. 62.1 ± 15.9 years; p = 0.69) and there were no differences in baseline characteristics or laboratory parameters at admission (Table 1). Low-flow time was shorter in patients with AED (14.5±12.9 vs 22.0 ± 15.5 p = 0.04). Therapeutic hypothermia was more frequent in the group without AED (64.8% vs 52.4%; p = 0.001). No differences were observed in the days of admission or invasive mechanical ventilation. In-Hospital mortality was significantly lower in patients with AED (25.9% vs 58.5%; p = 0.008), as well as the neurological prognosis favorable at discharge (55.6% vs 24.5%; p < 0.001).

In our cohort, resuscitation by lay bystanders was 23.7%, lower than reported rates in Catalonia (35%) or Madrid (30%), and substantially lower than Scandinavian countries (60-70%).AED use in OHCA and initial shockable rhythm was associated with 56% reduction in mortality (26% vs 59%, p=0.008) and 2.3-fold higher rate of favorable neurological outcome (56% vs 25%, p<0.001). These data highlight the need to support the first links in the chain of survival by increasing population education and the importance of early defibrillation, making it necessary to increase the public availability of AEDs and training in their use.

Baseline characteristic