Shock index (SI)
SI = HR / SBP
- Used when HR and SBP do not predict severity of hypovolemia in early stages
- May be used as secondary triage tool in mass casualty incidents
- 0.5-0.7 is normal
- >0.70-0.75 for occult shock or requirement of life-saving intervention
- Levitan, Richard M. Fundamentals of Airway Management. 3rd ed. Irving, TX: Emergency Medicine Residents' Association, 2015.
- Vassallo J et al. Usefulness of the Shock Index as a secondary triage tool. J R Army Med Corps. 2015 Mar;161(1):53-7.