Emergency
Shock Index (SI)
Identifies early hypovolemic or hemorrhagic shock.
&category=Emergency)
Enlarge
Parameters
Shock Index (SI) Result
--
Formula
Shock Index = Heart Rate (bpm) / Systolic Blood Pressure (mmHg)Clinical Pearls
Very useful in trauma and postpartum hemorrhage. A normal SBP can be maintained by compensatory tachycardia during early hemorrhage; the Shock Index unmasks this occult shock.
Limitations
May be falsely lowered in patients on beta-blockers or with baseline bradycardia, or falsely elevated in patients with pain/anxiety-induced tachycardia without shock.