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Shock Index

Shock index is heart rate divided by systolic blood pressure. Normal is about 0.5–0.7; ≥1.0 suggests significant hypovolemia or shock and predicts transfusion need and mortality in trauma, sepsis and bleeding.

  • Heart rate (/min)
  • Systolic blood pressure (mmHg or kPa)
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Interpretation

ResultMeaning
0.5–0.7Normal
0.7–0.99Elevated: monitor closely
≥ 1.0Shock likely

Formula

Shock index = heart rate (bpm) ÷ systolic blood pressure (mmHg)

Clinical pearls

  • Beta-blockers, pacemakers, pain and anxiety confound heart rate and hence shock index.
  • Trend matters: a rising shock index during resuscitation is more informative than a single value.

Examples

shock index hr 120 sbp 100shock index for pulse 110 and blood pressure 90/60si hr 72 bp 130/80

FAQ

What is a normal shock index?

Approximately 0.5 to 0.7 in healthy adults.

What shock index is concerning?

A shock index of 1.0 or higher suggests significant hemodynamic compromise and is associated with higher transfusion requirements and mortality.

Evidence

  1. Allgöwer M, Burri C. ["Shock index"]. Dtsch Med Wochenschr 1967;92:1947–50.

Cardiology · Reviewed 2026-10-14 · Methodology