Outcomes and Regional Care Patterns of Critically Ill Pediatric Emergency Patients: A Population-Based Registry Study

Clarifying clinical features of critically ill pediatric patients is essential for optimizing the regional emergency care system. However, the relationships between hospital case volume, interhospital transfer, and outcomes, including causes of death, remain unclear.

An observational study was conducted using prospectively collected data on critically ill patients aged 15 years or younger. Patients enrolled in this study were those who met the criteria for emergency and critical care unit management in Fukuoka Prefecture, Japan, from June 2014 to May 2019. Data on etiologic categories, outcomes, interhospital transfer, and use of intensive care interventions were collected. Hospitals were classified according to patient volume (high-volume: ≥ 100 and low-volume: < 100 patients during the observation period).

Among 3124 patients, 891 (28.5%) were infants (< 1 year). The annual incidence was 0.85 per 1000 children. Endogenous, exogenous, and "undetermined" etiologies accounted for 2481 (79.4%), 495 (15.8%), and 148 (4.7%) patients, respectively. Of 327 deaths (10.5%), 157 (48.0%) occurred in infants, and 89 (56.7%) of infant deaths were classified as "undetermined". In-hospital mortality among admitted patients was higher in low-volume hospitals (8.7% vs. 5.3%, p < 0.01), as was the proportion of "undetermined" deaths (49.5% vs. 28.8%, p < 0.01). Transferred patients had higher ICU admission rates (62.5% vs. 52.6%, p < 0.01), without higher mortality among admitted patients.

Critically ill infants had high mortality, and many deaths remained undetermined. These findings highlight the need to strengthen regional transport systems and postmortem evaluation in pediatric emergency care.