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Emergency/ICUShock Index

Shock Index Calculator

Calculate shock index from heart rate and systolic blood pressure.

Input

bpm
mmHg

Shock Index

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About

This shock index calculator uses the SI formula heart rate divided by systolic blood pressure (HR/SBP). Shock Index is a simple vital-sign ratio used as an early indicator of hemodynamic instability and occult shock, particularly in trauma, hemorrhage, and sepsis. A normal SI is 0.5–0.7. An elevated SI may identify patients at risk before traditional vital sign thresholds are breached.

Formula

Shock Index (SI) = Heart Rate / Systolic Blood Pressure

Interpretation

Shock IndexInterpretation
0.5 – 0.7Normal
0.7 – 1.0Elevated — concern for early shock
> 1.0Significant shock
> 1.5Severe shock

References

  1. Allgöwer M, Burri C. Schockindex. Dtsch Med Wochenschr. 1967;92(43):1947-1950.
  2. Mutschler M, et al. Renaissance of the shock index as a predictor for outcome in patients with polytrauma. J Trauma Acute Care Surg. 2013;74(4):1009-1015.

FAQ

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Disclaimer

Educational and informational reference only. Not intended to replace professional medical advice, diagnosis, treatment, or independent verification.