Shock Index
Heart rate divided by systolic blood pressure — a simple bedside marker that can flag early hemodynamic compromise before hypotension develops.
Formula
Shock index = Heart rate / Systolic BP
Result
Enter all values to see the result.
Limitations
- A single elevated value is a screening flag, not a diagnosis — it should prompt closer assessment (lactate, exam, trend), not a specific intervention by itself.
- Affected by anything that independently changes heart rate (pain, anxiety, beta-blockade, pacemaker) or blood pressure, which can produce false positives or false negatives.
- Derived mainly from trauma and sepsis cohorts; its performance in other populations is less well established.
References
- Allgöwer M, Burri C. Schockindex. Deutsche Medizinische Wochenschrift. 1967 (original description of the shock index).
Clinical Context & Relevant Topics (5)
Disease ReferenceCellular dysoxia, DO2/VO2 physiology, the 4 shock phenotypes, dynamic fluid responsiveness (PLR/PPV) vs fluid tolerance (VExUS), and vasoactive pharmacology.
The trauma lethal diamond (hypothermia, acidosis, coagulopathy, hypocalcemia), 1:1:1 massive transfusion (PROPPR trial), early TXA (CRASH-2), and TEG/ROTEM algorithms.
Pulmonary vascular occlusion, acute RV pressure overload, ESC/AHA risk stratification, systemic thrombolysis, catheter-directed therapies, and hemodynamic support.
Primary pump failure, SCAI staging (A–E), PAC hemodynamics (CPO, PAPi), inotrope selection, emergent revascularization, and mechanical circulatory support.
The subset of sepsis with profound circulatory and cellular/metabolic abnormality — clinically identified by a vasopressor requirement to maintain MAP ≥ 65 mmHg plus lactate > 2 mmol/L despite adequate fluid resuscitation.