Out-of-Hospital Pediatric Cardiac Arrest: Where Are We Now and Where Do We Need to Go?

Abstract

Out-of-hospital pediatric cardiac arrest is difficult to study, and I congratulate the authors in this month’s Annals of Emergency Medicine for their thorough systematic review of the current state of knowledge. With due respect to the investigators who contributed to this knowledge base and to the authors of this report, I suspect that many Annals readers may feel uncertain about what we really know about out-of-hospital pediatric cardiac arrest and, more importantly, how that knowledge can be used to improve outcome. Other than knowing that outcome after out-of-hospital pediatric cardiac arrest is poor, this systematic review illustrates important limitations of this type of review because of the limitations of the studies on which it is based. The author’s initial goals of clearly identifying gaps in our knowledge and determining the effects of commonly used interventions on outcome are difficult to deduce from the available data. Although 41 studies and more than 5,300 children are included in the identified studies, a minority of these studies could be evaluated when looking at the association of specific interventions on outcome, such as bystander cardiopulmonary resuscitation or the association of the initial rhythm with outcome in various patient causal categories. As the authors discuss under study limitations, observational studies often use inconsistent study designs. This inconsistency is clearly true for cardiac arrest studies and is illustrated by the more than 7-fold variation in the reported incidence of cardiac arrest (2.6 to 19.7 cases per 100,000 pediatric population) and the surprising results about outcome after traumatic-induced arrest. As the authors correctly note, however, the method of patient inclusion into the National Pediatric Trauma Registry database likely included children who were not in cardiac arrest. Once children in these National Pediatric Trauma Registry reports were excluded, traumatic cardiac arrest resulted in poor outcome, as expected. Throughout the more than 20 years of reports included in this review, imprecise inclusion and exclusion criteria were used. The pediatric Utstein guidelines for reporting data were not published until 1995 and were incorporated to various degrees in subsequent reports. In addition to variable inclusion criteria, different outcome definitions were used. Furthermore, the most commonly used functional outcome used was designed