Bonus: what is a shock index?

Shock index

The shock index is a predictive tool, used to determine risk of negative outcomes in unstable patients.

Shock index = HR / SBP

A normal, well perfused individual has a shock index of 0.5-0.7 . The closer the patient gets to a shock index of 1.0 or higher, the greater the risk of a serious perfusion deficit.

We can use shock index in the field to determine our patient’s initial stability, and to assess for the potential need to initiate fluid resuscitation, and potential ALS medications.