Utility of Shock Index and Pediatric Age-Adjusted Shock Index in Predicting Severe Sepsis and Septic Shock.

Introduction: Early recognition of severe sepsis and septic shock in the pediatric emergency department (PED) is crucial for the success of early targeted therapy. The shock index (SI) and pediatric age-adjusted shock index (SIPA) are promising noninvasive tools for early risk stratification. This study aimed to evaluate the predictive performance of SI, SIPA, and modified indexes in severe outcomes.

Methods: This single-center retrospective cohort study included 238 pediatric patients aged 1 month to 18 years who met systemic inflammatory response syndrome criteria. Clinical findings and vital signs were collected at presentation. SI, SIPA, and modified indices were calculated using heart rate and systolic blood pressure. Biomarkers, including lactate and immature granulocyte percentage (IG%), were also recorded.

Results: Of 238 patients, 49 (20.6%) had severe sepsis or septic shock. SI ≥1.81 showed an AUC of 0.815, sensitivity of 81.6%, and specificity of 67.7%. SIPA had a sensitivity of 91.8% but a lower specificity (45.0%). Pediatric Shock Index and Temperature-adjusted and Age-adjusted Mean Shock Index had AUCs of 0.443 and 0.734, respectively. Age-specific SI cutoffs improved predictive performance, particularly in younger children. Combining SI with IG% or lactate enhances diagnostic accuracy.

Conclusions: SI and SIPA are practical tools for early recognition of severe sepsis in children. Age-adjusted SI cutoffs improve accuracy. Diagnostic performance was further enhanced when combined with IG% and lactate, supporting their integration in PED clinical decision-making.