This medical tool estimates adult shock index, modified shock index, age shock index, mean arterial pressure, and pulse pressure. It is for educational and screening support only, not a diagnosis.
Enter Patient Values
Example Data Table
| Case | Age | HR | SBP | DBP | SI | MSI | ASI | Band |
|---|---|---|---|---|---|---|---|---|
| A | 32 | 76 | 124 | 78 | 0.613 | 0.814 | 19.61 | Expected Adult Range |
| B | 45 | 98 | 110 | 70 | 0.891 | 1.176 | 40.10 | Borderline Elevated |
| C | 67 | 120 | 96 | 58 | 1.250 | 1.698 | 83.75 | High Risk |
| D | 79 | 132 | 84 | 48 | 1.571 | 2.200 | 124.11 | Critical |
These example rows are illustrative and should not replace bedside assessment.
Formula Used
| Metric | Formula | Meaning |
|---|---|---|
| Shock Index | SI = Heart Rate ÷ Systolic Blood Pressure | Compares pulse to systolic pressure. |
| Mean Arterial Pressure | MAP = (SBP + 2 × DBP) ÷ 3 | Weighted average perfusion pressure estimate. |
| Modified Shock Index | MSI = Heart Rate ÷ MAP | Adds diastolic pressure through MAP. |
| Age Shock Index | ASI = Age × SI | Extends SI by including age burden. |
| Pulse Pressure | PP = SBP − DBP | Shows systolic-diastolic spread. |
Adult reference cutoffs vary by setting, population, and protocol. This page uses practical screening bands for fast interpretation.
How to Use This Calculator
- Enter age, heart rate, systolic pressure, and diastolic pressure.
- Add respiratory rate, SpO₂, and temperature if available.
- Press Calculate to show results above the form.
- Review shock index, modified shock index, age shock index, MAP, and pulse pressure.
- Use the interpretation badge to quickly identify risk level.
- Download CSV or PDF for case review, notes, or reporting.
Frequently Asked Questions
1) What is shock index?
Shock index is heart rate divided by systolic blood pressure. It is a quick screening ratio that may help identify circulatory stress earlier than either number alone.
2) What range is usually considered normal in adults?
A commonly cited adult range is about 0.5 to 0.7. Values above that may deserve closer review, especially when symptoms or poor perfusion signs are present.
3) Why does this page also calculate modified shock index?
Modified shock index uses mean arterial pressure instead of systolic pressure alone. That adds diastolic information and can provide a broader hemodynamic view.
4) What is age shock index?
Age shock index multiplies age by shock index. It is sometimes used in risk stratification because older adults may tolerate abnormal physiology differently.
5) Can a normal shock index rule out shock?
No. A normal value does not exclude serious illness. Use the result with mental status, skin signs, urine output, lactate, oxygenation, and the full clinical picture.
6) Is this calculator suitable for children?
Not reliably. Pediatric normal ranges differ by age, so adult shock index thresholds should not be applied directly to children.
7) Why are respiratory rate, SpO₂, and temperature optional?
They do not define shock index directly, but they improve bedside context. Abnormal respiratory effort, oxygen saturation, or temperature can strengthen concern about underlying instability.
8) Do the CSV and PDF buttons save data on the server?
No. The export files are generated in the browser from the current result shown on the page, so nothing extra needs to be stored server-side.