The Predictive Value and Appropriate Ranges of Prehospital Physiological Parameters for High-risk Injured Children

Objectives: To assess: (1) the relative importance of prehospital physiological measures in identifying high-risk children; (2) whether different age-based criteria should be used for each prehospital physiological measure; and (3) outcome-based appropriate ranges of physiological measures in injured children.

Methods: This was a retrospective cohort analysis of injured children 0 to 14 years transported by emergency medical services to 48 statewide hospitals from January 1, 1998, through December 31, 2003. We analyzed prehospital physiological measures, including Glasgow Coma Scale score (GCS), systolic blood pressure (SBP), respiratory rate (RR), heart rate, shock index (heart rate/SBP), and airway intervention. "High-risk" children were defined as those with in-hospital mortality, major nonorthopedic surgery, intensive care unit stay greater than or equal to 2 days, or Injury Severity Score greater than or equal to 16. Specific age groups included 0 to 2 years, 3 to 5 years, 6 to 10 years, and 11 to 14 years.

Results: A total of 3877 injured children were included in the analysis, of which 1111 (29%) were high risk. Prehospital GCS was the variable of greatest importance in identifying high-risk children, followed by (in order) airway intervention, RR, heart rate, SBP, and shock index. Age modified the effect of prehospital RR (P = 0.0046), heart rate (P = 0.01), and SBP (P = 0.02). There was a linear relationship between GCS and outcome that was consistent across all ages. Specific age-based ranges of other physiological measures were identified for high-risk children.

Conclusions: Prehospital GCS and respiratory compromise were the most important physiological measures in identifying high-risk injured children. Age-specific criteria should be considered for RR, heart rate, and SBP.