Objectives: To determine etiology of pediatric OHCA in a population-based sample from autopsy and coroner's diagnosis.
Design: As part of the Ontario Pre-hospital Advanced Life Support (OPALS) study, we conducted a prospective cohort study including children below age 19 years with OHCA in an 11-year period. Deaths were matched with provincial coroner's office records and autopsies and investigation notes were reviewed.
Results: From 1992 to 2002, there were 474 cardiac arrests in children below 19 years of age giving an annual incidence of 59.7 per million children. Mean age was 5.8 (S.D. 6.3), 43.0% were <1 year of age, males were 59.1%. 25.1% were bystander witnessed and 20.3% received bystander CPR. 1.9% survived to discharge. Four hundred and thirty nine matched to coroner's office records. Annual incidence rates per million by age groups were: 175.0 (age 1-4 years), 33.0 (age 5-14 years) and 61.6 (age 15-18). Annual incidence rates per million according to coroner's cause of death were: natural (26.2), accidental (17.4), suicide (3.7) and homicide (1.9). Post-mortem rate was 84.3% and Mean Injury Severity Score was 31.4 (S.D. 16.5). The commonest causes of natural death were SIDS (30.3%), cardiovascular (19.2) and respiratory (18.3%). The commonest causes of accidental death were drowning (27.5%), residential accidents (18.8%), fire (13.0%) and motor vehicle collisions (12.3%).
Conclusion: The highest mortality rates were among children age <4 years. 52.6% of deaths were from 'unnatural' causes (accidental, suicide, homicide, undetermined). Our findings will be useful for planning prevention, treatment and future research of pediatric OHCA.