Association of subsequent treated shockable rhythm with outcomes after paediatric out-of-hospital cardiac arrests: A nationwide, population-based observational study

AIM: Among patients with paediatric out-of-hospital cardiac arrests (OHCAs), most have an initial non-shockable rhythm with poor outcomes. There is a subset who developed shockable rhythms. This study aimed to investigate the association between subsequent shock delivery and outcomes after paediatric OHCAs. METHODS: We analysed records of 19,095 children (aged <18 years) with OHCA and initial non-shockable rhythm. Data were obtained from a Japanese nationwide database for 13 years (2005–2017). The primary outcome measure was 1-month neurologically intact survival, defined as cerebral performance category 1–2. RESULTS: Among patients with pulseless electrical activity (PEA, n = 3,326), there was no significant difference between those with subsequent treated shockable rhythm (10.0% [11/109]) and those with sustained non-shockable rhythm (6.0% [192/3,217], p = 0.10) with respect to the neurologically intact survival rate. Among asystole patients (n = 15,769), the neurologically intact survival rate was significantly higher in the subsequent treated shockable rhythm group (4.4% [10/227]) than in the sustained non-shockable rhythm group (0.7% [106/15,542], p < 0.0001). Subsequent treated shockable rhythm with a shock delivery time (time from emergency medical services [EMS]-initiated cardiopulmonary resuscitation [CPR] to shock delivery) ≤9 min was associated with increased odds of neurologically intact survival compared with sustained non-shockable rhythm (PEA, adjusted odds ratio, 2.45 [95% confidence interval, 1.16–5.16], p = 0.018; asystole, 9.77 [4.2–22.5], p < 0.0001). CONCLUSION: After paediatric OHCAs, subsequent treated shockable rhythm was associated with increased odds of 1-month neurologically intact survival regardless of whether the initial rhythm was PEA or asystole, only when the shock was delivered ≤9 min of EMS-initiated CPR.