Pediatric Shock Index Calculator (SIPA)
Calculate age-adjusted pediatric shock index from heart rate and systolic blood pressure, then compare the result with SIPA abnormal cutoffs by age.
Last reviewed: February 26, 2026
Clinical disclaimer
Shock Index = heart rate / systolic BP. SIPA thresholds: 1-5 years >1.2, 6-12 years >1.0, 13+ years >0.9.
How SIPA works
The shock index is heart rate divided by systolic blood pressure. SIPA adjusts the abnormal threshold by age group to account for normal pediatric vital sign ranges.
- Calculate shock index = HR / SBP.
- Compare the value to the age-adjusted cutoff.
- Abnormal SIPA suggests higher risk and need for close monitoring.
Age bands and cutoffs
- 1-5 years: abnormal if SI > 1.2.
- 6-12 years: abnormal if SI > 1.0.
- 13+ years: abnormal if SI > 0.9.
Most SIPA reference tables start at 1 year of age; use extra caution in infants.
Interpretation tips
- An abnormal SIPA is not diagnostic but can flag early shock or higher acuity.
- Combine with perfusion, mental status, and overall clinical trajectory.
- Repeat vital signs and reassess after interventions.
Reassessment cadence
- Initial abnormal SIPA: repeat full vital set promptly after first stabilization steps.
- Persistent concern or active intervention: reassess at short interval per local pathway.
- Improving stable trend: continue scheduled checks with explicit trend documentation.
Escalation triggers
- Rising SIPA trend with worsening perfusion, altered mental status, or respiratory distress.
- Hypotension for age or new hemodynamic instability despite initial interventions.
- Disagreement between bedside appearance and reported vital-sign data quality.
- Repeated abnormal SIPA without expected response to treatment.
Shift handoff checklist
- Most recent HR/SBP values, SIPA result, and age-band threshold used.
- Trend direction and interval between repeated measurements.
- Interventions performed and observed clinical response.
- Next reassessment time and concrete escalation threshold for covering team.
Related calculators
References
Frequently asked questions
Shock index is the ratio of heart rate to systolic blood pressure (HR/SBP). Higher values can indicate circulatory compromise.
SIPA is the pediatric age-adjusted shock index. It uses different abnormal thresholds by age group rather than a single cutoff.
Most published SIPA tables start at 1 year of age. For infants under 1 year, interpret the shock index with extra caution and clinical context.
Not always. An abnormal SIPA should prompt closer assessment and monitoring, but it does not replace clinical judgment or other findings.
Include raw HR/SBP values, age-band threshold, trend direction, interventions done, and explicit escalation triggers. This reduces delayed recognition when teams rotate.