Out-of-hospital cardiac arrests in the young population; a 6-year review of the Irish out-of-hospital cardiac arrest register

Study purpose: Out-of-hospital cardiac arrests (OHCA) in the young population have only been examined in a limited number of regional studies. Hence, we sought to describe OHCA characteristics and predictors of survival to hospital discharge for the young Irish population. Study design: An observational analysis of the national Irish OHCA register for all OHCAs aged ≤35 years between January 2012 and December 2017 was performed. The young population was categorised into three age groups: ≤1 year, 1-15 years and 16-35 years. Multivariable logistic regression was used to determine the independent predictors of survival to hospital discharge. Results: A total of 1295 OHCAs aged ≤35 years (26.9% female, median age 25 (IQR 17-31)) had resuscitation attempted. OHCAs in those aged ≥16 years (n=1005) were more likely to happen outside the home (38.5% vs 22.8%, p<0.001) and be of non-medical aetiology (59% vs 27.6%, p<0.001) compared with those aged <16 years (n=290). Asphyxiation, trauma and drug overdoses accounted for over 90% of the non-medical OHCAs for those 16-35 years. Overall survival to hospital discharge for the cohort was 5.1%; survival was non-significantly higher for those aged 16-35 years compared with those aged 1-15 years (6.0%, vs 2.8% p=0.93). Independent predictors of survival to hospital discharge included bystander witnessed OHCA, a shockable initial rhythm and a bystander defibrillation attempt. Conclusions: The high prevalence of non-medical OHCAs and the OHCA location need to be considered when developing OHCA care pathways and preventative strategies to reduce the burden of OHCAs in the young population.