Maayke Hunfeld

8 Chapter 1 Introduction Pediatric cardiac arrest (CA) is a life threatening condition. A child’s heart suddenly stops pumping blood around the body with an abrupt loss of vital signs and consciousness. Without cardiopulmonary resuscitation (CPR), mortality is nearly always 100%. In the United States, with a population of approximately 300 million people, each year 15.000 children experience an in-hospital cardiac arrest (IHCA) and approximately 6000 an out-of-hospital cardiac arrest (OHCA) (1-4). In The Netherlands, with a population of approximately 17 million people the incidence of pediatric CA is unknown, due to lack of a national pediatric CA registry. In the Erasmus MC-Sophia Children’s hospital (referral area 4 million inhabitants), a total of 474 pediatric CA events, both IHCA and OHCA, were documented between 2002 and 2011, which equates to 50 CAs per year (5). Only one study described the incidence of pediatric OHCA in the Netherlands; Bardai et al reported an incidence of 9 per 100,000 pediatric person-years with a mortality rate of 95% (6). In 2020, there were 3.775.258 Dutch residents between 0-20 years old (7). Based on Bardai’s paper, this means that approximately 340 children and adolescents experienced an OHCA in 2020. During CA, cessation of cerebral oxygen delivery occurs resulting in cerebral hypoxic ischemia with different effects on the central nervous system (8). In case of return of circulation (ROC), post-cardiac arrest syndrome can arise causing secondary global brain injury due to reperfusion and the frequently used high inspirational oxygen supply with additional hyperoxic damage (9-13). Areas most vulnerable to ischemic hypoxic injury are vascular end zones, hippocampus, insular cortex, cerebellar Purkinje cells and basal ganglia (14-18). The extent of initial brain injury combined with the therapeutic modalities determines the overall neurological outcome of children after CA and can vary from no neurological deficits to, at the other end of the spectrum, brain death. By starting immediate adequate basic life support (BLS) or advanced pediatric life support (APLS), the lack of oxygen delivery to the brain (resulting in direct brain ischemia) can be reduced. Guidelines have been developed to optimize BLS, APLS and pediatric post-CA care with the purpose to increase survival rates and prevent (or limit) the occurrence of secondary brain injury (19-21). CAs are categorized into two separate groups depending on the location of the arrest: IHCA and OHCA. Whereas children with IHCA are already hospitalized prior to the arrest with actual underlying diseases such as sepsis, pneumonia, cardiac failure and/or multi-organ failure or need for support, children with OHCA are more likely