Maayke Hunfeld

9 Introduction to be previously healthy with a sudden unexpected arrest. This makes children with OHCA a more homogeneous group. For this reason, we focus on OHCA in this thesis. Causes of Out-of-hospital cardiac arrest Whereas in adults OHCAs are predominantly caused by cardiac diseases, pediatric OHCAs are more attributable to non-cardiac causes. In a retrospective multi-center cohort study by Moler et al. with 138 pediatric OHCA patients, main causes were respiratory (81%), followed by cardiac causes (19%)(22). A large Japanese prospective nationwide cohort study including 5758 children with OHCA showed that 70% of OHCAs had a non-cardiac origin and only 30% a presumed cardiac origin (23). Causes of death after Out-of-hospital cardiac arrest The overall survival rate of children with OHCA is low. The vast majority die pre- hospital (no return of circulation (ROC), cessation of CPR) or during hospital admission (24, 25). Causes of non-survival during hospital admission are mostly: no ROC after arriving at the emergency department, re-arrest with no ROC, brain death, multiple organ failure due to additional hypoxic damage to organs other than the brain such as heart and kidneys, severe neurological injury, withdrawal of life sustaining therapy (WLST). In a large American/Canadian cohort including 1738 children experiencing OHCA, ROC was achieved in 36%. In another study from the United States with 599 children with OHCA, the percentage of ROC was comparable (24, 26). In a study by Moler et al., describing outcome in children with OHCA and subsequently ROC, survival to hospital discharge was 38% (22). Only in one study from the United States by Du Pont et al., the causes and timing of death are described in 191 children admitted to a Pediatric Intensive Care Unit (PICU) with ROC after OHCA (27). Neurological injury was the most common cause of death in their tertiary care center. Forty-five percent died before PICU discharge. Of those, 47% was declared brain death, 34% died after WLST because of poor neurologic prognosis. Re-arrest occurred in 9% and 10% died due to WLST for refractory circulatory failure. Median time from OHCA to death after WLST because of poor neurologic prognosis was 4 days (IQR 1-5 days) (figure 1). Actual research question: In the absence of nationwide data fromThe Netherlands, we wondered what the causes of death were in children with OHCA who presented in our hospital. 1