Oxygen Delivery / DO₂ Calculator
Calculate oxygen delivery using cardiac output and arterial oxygen content. DO₂ connects the oxygen carried in the blood with how much blood flow is delivering that oxygen to tissues each minute.
Calculator
Calculate Oxygen Delivery
Formula: DO₂ = Cardiac Output × CaO₂ × 10.
Oxygen Delivery
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mL O₂/min
Enter cardiac output and CaO₂ to calculate oxygen delivery.
Formula
Oxygen Delivery Formula
DO₂ = Cardiac Output × CaO₂ × 10
Example: CO 5 L/min and CaO₂ 20 mL/dL
DO₂ = 5 × 20 × 10 = 1000 mL O₂/min
Example: CO 5 L/min and CaO₂ 20 mL/dL
DO₂ = 5 × 20 × 10 = 1000 mL O₂/min
RT Memory Trick
Delivery Requires Content and Flow
CaO₂ tells you how much oxygen is in each dL of arterial blood. Cardiac output tells you how much blood is moving each minute.
Remember:
Oxygen delivery needs both oxygen content and blood flow. A patient can have a normal CaO₂ but poor delivery if cardiac output is low.
Oxygen delivery needs both oxygen content and blood flow. A patient can have a normal CaO₂ but poor delivery if cardiac output is low.
Interpretation
How to Interpret DO₂
| DO₂ Pattern | Meaning | Clinical Connection |
|---|---|---|
| About 900–1100 mL/min | Typical adult resting range | Often adequate at rest if tissue demand is normal. |
| Low DO₂ from low CaO₂ | Not enough oxygen content | Anemia, hypoxemia, low saturation, abnormal hemoglobin. |
| Low DO₂ from low cardiac output | Not enough blood flow | Shock, heart failure, poor perfusion. |
| High demand state | Normal DO₂ may not be enough | Fever, sepsis, agitation, work of breathing. |
Clinical Pearl
Hypoxia Can Be a Delivery Problem
Low tissue oxygen can happen because oxygen loading is poor, oxygen-carrying capacity is low, or perfusion is inadequate.
Low PaO₂
Oxygen loading problem.
Oxygen loading problem.
Low hemoglobin
Oxygen-carrying capacity problem.
Oxygen-carrying capacity problem.
Low cardiac output
Oxygen delivery/perfusion problem.
Oxygen delivery/perfusion problem.
Clinical connection
Look beyond SpO₂: assess Hb, CO, perfusion, lactate, mental status, and work of breathing.
Look beyond SpO₂: assess Hb, CO, perfusion, lactate, mental status, and work of breathing.
Common Student Mistakes
Avoid These Errors
Forgetting the ×10
The factor converts dL to L because CaO₂ is mL/dL and cardiac output is L/min.
The factor converts dL to L because CaO₂ is mL/dL and cardiac output is L/min.
Assuming normal SpO₂ means normal delivery
Hemoglobin and cardiac output may still be low.
Hemoglobin and cardiac output may still be low.
Ignoring tissue demand
Fever, sepsis, and work of breathing can increase oxygen needs.
Fever, sepsis, and work of breathing can increase oxygen needs.
Focusing only on lungs
Oxygen delivery is a cardiopulmonary concept.
Oxygen delivery is a cardiopulmonary concept.
Continue Learning
Connect DO₂ to CaO₂ and Hypoxia
Review oxygen content and hypoxia vs hypoxemia to understand why oxygen problems are not always visible from PaO₂ alone.