Interfacility Transport Shock Index Is Associated With Decreased Survival in Children

BACKGROUND: Shock index, the ratio of heart rate to systolic blood pressure that changes with age, is associated with mortality in adults after trauma and in children with sepsis. We assessed the utility of shock index to predict sepsis diagnosis and survival in children requiring interfacility transport to a tertiary care center. METHODS: We studied children aged 1 month to 21 years who had at least 2 sets of vital signs recorded during interfacility transport to the Children’s Hospital of Pittsburgh by our critical care transport team. Subjects were divided into 4 age groups: group 1 (<1 year), group 2 (1–3 years), group 3 (4–11 years), and group 4 (≥12 years). Children were also grouped into sepsis or nonsepsis group based on the International Classification of Diseases, Ninth Revision categories. Primary outcome was survival to hospital discharge. RESULTS: Of 3519 children studied, 493 (14%) had sepsis. Initial shock index decreased with increasing age: group 1, 1.45 ± 0.42 (mean ± SD); group 2, 1.35 ± 0.32; group 3, 1.20 ± 0.34; and group 4, 1.00 ± 0.32 (P < 0.001). Initial shock index was increased in children with sepsis versus those with no sepsis overall and in all age groups (all P < 0.05). Initial shock index showed a trend for association with survival in univariate analysis (P = 0.05) but was not associated with survival in a multivariable logistic regression. Highest quartile of shock index was associated with need for intensive care unit admission posttransport. CONCLUSIONS: Increased shock index in children requiring intrafacility transport was associated with hospital discharge diagnosis of sepsis but not hospital survival.