SIPA — Shock Index Pediatric Adjusted

The Shock Index Pediatric Adjusted (SIPA) is an age-adjusted version of the adult Shock Index (heart rate ÷ systolic blood pressure) calibrated to normal pediatric vital sign ranges. Normal adult Shock Index (SI = HR/SBP) threshold is ≥ 0.8. Because children normally have higher heart rates and lower blood pressure than adults, the SIPA uses age-stratified cutoffs: SIPA ≥ 1.22 for ages 4–6 years, ≥ 1.0 for ages 7–12, and ≥ 0.9 for ages 13–16. An elevated SIPA predicts need for massive transfusion, blood product administration, and mortality in pediatric trauma.