🩸 ATLS Hemorrhagic Shock Classification
Classify hemorrhagic shock (Class I–IV) with the ATLS framework.
Clinical takeaway
Class III onward needs blood products and source control within 60 min.
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When to use
Estimate blood loss and guide trauma resuscitation intensity.
How it works
Class by the worst of heart rate, systolic BP, mental status and urine output. I < 15%, II 15–30%, III 30–40%, IV > 40% blood volume (70 kg).
Key points
- Class III onward needs blood products and source control within 60 min.
- Class IV needs massive transfusion and emergency surgery.
- Integrate with shock index, lactate and base deficit.
References
Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Heart rate | 130 /min |
|---|---|
| Systolic BP | 95 mmHg |
| Mental status | Normal |
| Urine output | > 30 mL/h |
→ATLS classClass III
- Classification：Worst parameter → Class III (HR 130, SBP 95, mental status/urine output)
- Estimated blood loss：30–40% (1500–2000 mL)
- Resuscitation：Aggressive resuscitation + early blood products; definitive hemorrhage control within 60 min; assess for massive transfusion (ABC score)
| Heart rate | 130 /min |
|---|---|
| Systolic BP | 95 mmHg |
| Mental status | Confused/lethargic |
| Urine output | < 5 mL/h (minimal/none) |
→ATLS classClass IV
- Classification：Worst parameter → Class IV (HR 130, SBP 95, mental status/urine output)
- Estimated blood loss：> 40% (> 2000 mL)
- Resuscitation：Immediate massive transfusion + emergency surgical hemostasis; life-threatening
Frequently asked questions
- What is ATLS Hemorrhagic Shock Classification?
- Classify hemorrhagic shock (Class I–IV) with the ATLS framework.
- How is ATLS Hemorrhagic Shock Classification calculated? What is the core formula?
- Class by the worst of heart rate, systolic BP, mental status and urine output. I < 15%, II 15–30%, III 30–40%, IV > 40% blood volume (70 kg).
- When is ATLS Hemorrhagic Shock Classification used?
- Estimate blood loss and guide trauma resuscitation intensity.
- What are the key clinical points for ATLS Hemorrhagic Shock Classification?
- Class III onward needs blood products and source control within 60 min. Class IV needs massive transfusion and emergency surgery. Integrate with shock index, lactate and base deficit.
- What are the limits and cautions when using ATLS Hemorrhagic Shock Classification?
- For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
- How is ATLS Hemorrhagic Shock Classification calculated in practice? Can you show a worked example?
- Inputs: Heart rate 130 /min, Systolic BP 95 mmHg, Mental status Normal, Urine output > 30 mL/h → Result: ATLS class Class III（Classification: Worst parameter → Class III (HR 130, SBP 95, mental status/urine output), Estimated blood loss: 30–40% (1500–2000 mL), Resuscitation: Aggressive resuscitation + early blood products; definitive hemorrhage control within 60 min; assess for massive transfusion (ABC score)） Inputs: Heart rate 130 /min, Systolic BP 95 mmHg, Mental status Confused/lethargic, Urine output < 5 mL/h (minimal/none) → Result: ATLS class Class IV（Classification: Worst parameter → Class IV (HR 130, SBP 95, mental status/urine output), Estimated blood loss: > 40% (> 2000 mL), Resuscitation: Immediate massive transfusion + emergency surgical hemostasis; life-threatening）