Application of the Shock Index to the prediction of need for hemostasis intervention.

Introduction: The traditional method to identify hemorrhage after trauma has been vital signs-based. More recent attempts have used mathematical prediction models, but these are limited by the need for additional data including a Focused Assessment with Sonography for Trauma exam, or an arterial blood gas. Shock Index (SI) is the mathematical relationship of the heart rate divided by the systolic blood pressure; the cutoff of >0.