Shock Index Calculator
Calculate the Shock Index (Heart Rate / Systolic BP) for early detection of hemodynamic instability. A simple but sensitive marker for occult shock.
Shock Index Calculator
Shock Index
0.67
Normal
No hemodynamic compromise indicated
Clinical Guidance:
- • Vital signs within expected parameters
- • Continue routine monitoring
Adult Shock Index Scale
Normal
0.5 - 0.7 Compensated Shock
0.7 - 1 Mild Shock
1 - 1.3 Moderate Shock
1.3 - 1.7 Severe Shock
> 1.7Formula: Shock Index = Heart Rate / Systolic BP
Calculation: 80 / 120 = 0.67
Calculation: 80 / 120 = 0.67
References:
Allgöwer M, Burri C. Shock index. Dtsch Med Wochenschr. 1967;92(43):1947-1950.
Birkhahn RH, et al. Shock index in diagnosing early acute hypovolemia. Am J Emerg Med. 2005;23(3):323-326.
Interpretation Guide
- • Normal SI (0.5-0.7): No hemodynamic compromise
- • SI > 0.7: May indicate early compensated shock
- • SI > 1.0: Suggests significant hemodynamic instability
- • SI > 1.3: Associated with increased mortality and need for intervention
- • Trending: Serial measurements more valuable than single reading
Clinical Applications
- • Trauma triage and severity estimation
- • Early identification of occult hemorrhage
- • Ectopic pregnancy risk stratification
- • Post-surgical hemodynamic monitoring
- • Sepsis and dehydration assessment
Safety Note
The Shock Index is a screening tool and should not replace comprehensive clinical assessment. It may be less reliable in patients on beta-blockers, with pacemakers, during pregnancy, or in pediatric patients (who have different normal ranges). Always correlate with clinical presentation and follow local protocols. A normal SI does not exclude shock.