Effect of Defibrillation Dose and Waveform Characteristics on Defibrillation Success in Pediatric In-Hospital Cardiac Arrest

Introduction: Amplitude spectral area (AMSA) predicts successful defibrillation (DF) and return of spontaneous circulation (ROSC) in adults but has not been studied during pediatric in-hospital cardiac arrest (IHCA). Hypothesis: We characterized DF dose and AMSA during pediatric IHCA from a pediatric resuscitation quality (pediRES-Q) collaborative and hypothesized that a threshold value of AMSA could predict successful DF. Methods: Children <18 years with witnessed IHCA, ventricular fibrillation (VF) as the initial rhythm, and those who had complete CPR quality metric data captured from the bedside defibrillator (ZOLL R-Series, Chelmsford, MA) were studied. Energy dose, initial AMSA ( i AMSA) and pre-shock AMSA ( p AMSA) [2.5-sec ECG window before defibrillation] for predicting DF success were calculated, together with receiver operator (ROC) curves. Successful DF (sDF) was defined as return of an organized rhythm 5 seconds after DF. Sustained ROSC was defined as >20 minutes without chest compressions. Events with DF due to ventricular tachycardia, inappropriate shocks (i.e. supraventricular tachycardia, conduction block), unavailable AMSA values, and VF events using <1 J/kg for DF were excluded. Results: Between 2015-2018, 34 subjects (median age 7.4 years [1.3,13.1]; median weight 19.4 kgs [8.9, 41.7]) with IHCA due to VF were enrolled. We analyzed 26 shocks in 18 children < 8 years and 25 shocks in 16 children 8 to <18 years. For children < 8 years, the initial DF median dose/kg was 2.5 [2.3,3.3] J/kg with sDF in 14/26 (54%) shocks and sustained ROSC in 10/18 (56%) children. For those 8 to <18 years, initial DF median dose/kg was 3.0 [2.5,3.4] J/kg with sDF in 10/25 (40%) shocks and sustained ROSC in 10/16 (63%). AMSA was significantly higher prior to sDF than in unsuccessful DF ( p AMSA 19.14±8.11 vs.12.0±7.38 mV-Hz, p = 0.0021; i AMSA 19.08±7.38 vs. 11.04±6.57 mV-Hz, p = 0.0053). Area under the ROC curve was 0.765 for p AMSA and 0.796 for i AMSA. Conclusions: We characterized DF dose and AMSA during pediatric IHCA with an initial rhythm of VF and found that sDF was significantly associated with AMSA >19 mV-Hz. Future studies should determine the AMSA threshold that predicts sDF in children due to differences in heart size and cardiac arrest etiology.