The Cardiovascular
ToolsCalculators

Shock Index

Shock Index
Heart rate
bpm
Systolic blood pressure
mmHg
Complete the fields above to see the result.

When to use

  • Screening for occult haemorrhagic or septic shock when vital signs individually look reassuring.

Formula

Shock index = heart rate / systolic blood pressure. Normal 0.5-0.7; values >=0.9 suggest circulatory compromise.

Pearls and pitfalls

  • More sensitive than heart rate or blood pressure alone for early shock.
  • A modified shock index (HR / mean arterial pressure) is sometimes used as an alternative.

References

  1. Allgower M, Burri C. Dtsch Med Wochenschr. 1967;92(43):1947-50.