Shock Index as a Predictor of Morbidity and Mortality in Pediatric Trauma Patients

OBJECTIVES: Compared with unadjusted shock index (SI) (heart rate/systolic blood pressure), age-adjusted SI improves identification of negative outcomes after injury in pediatric patients. We aimed to further evaluate the utility of age-adjusted SI to predict negative outcomes in pediatric trauma.

METHODS: We performed an analysis of patients younger than 15 years using the National Trauma Data Bank. Elevated SI was defined as high normal heart rate divided by low-normal blood pressure for age. Our primary outcome measure was mortality. Secondary outcomes included need for a blood transfusion, ventilation, any operating room/interventional radiology procedures, and intensive care unit stay. Multiple logistic regressions were performed.

RESULTS: Twenty-eight thousand seven hundred forty-one cases met the study criteria. The overall mortality rate was 0.7%, and 1.7% had an elevated SI. Patients with an elevated SI were more likely (P < 0.001) to require blood transfusion, ventilation, an operating room/interventional radiology procedure, or an intensive care unit stay. An elevated SI was the strongest predictor for mortality (odds ratio [OR] 22.0) in pediatric trauma patients compared with hypotension (OR, 12.6) and tachycardia (OR, 2.6).

CONCLUSIONS: Elevated SI is an accurate and specific predictor of morbidity and mortality in pediatric trauma patients and is superior to tachycardia or hypotension alone for predicting mortality.