Oxygen Delivery Calculator
Calculate oxygen delivery (DO2) to tissues from cardiac output and arterial oxygen content. DO2 = CO x CaO2 x 10. Assess adequacy of oxygen supply in shock and respiratory failure.
❤️ Physiology📐 DO2 = CO x CaO2 x 10🧬 Biology
Cardiac output CO (L/min)
SpO2 or SaO2 (%)
Hemoglobin Hgb (g/dL)
PaO2 (mmHg, optional)
Please enter valid values.
Formula & Reference
| Variable | Symbol | Formula | Units |
|---|---|---|---|
| Oxygen Delivery Calculator | — | DO2 = CO x CaO2 x 10 | mL O2/min |
Step-by-Step Examples
Example 1
Normal Adult
CO=5 L/min, Hgb=14 g/dL, SaO2=98%.
- CaO2 = 1.34 x 14 x 0.98 = 18.38 mL/dL
- DO2 = 5 x 18.38 x 10 = 919 mL/min
- Normal range: 950-1150 mL/min
✓ DO2 = 919 mL/min (normal)
Example 2
Anemia
CO=5, Hgb=7 g/dL, SaO2=98%.
- CaO2 = 1.34 x 7 x 0.98 = 9.19 mL/dL
- DO2 = 5 x 9.19 x 10 = 460 mL/min
- Severely reduced — body compensates with high CO
✓ DO2 = 460 mL/min (critically low)
Example 3
Cardiogenic Shock
CO=2 L/min, Hgb=12, SaO2=90%.
- CaO2 = 1.34 x 12 x 0.90 = 14.47
- DO2 = 2 x 14.47 x 10 = 289 mL/min
- Life-threatening oxygen supply failure
✓ DO2 = 289 mL/min — critical shock
Real-World Applications
Critical Care
DO2 monitoring guides resuscitation goals in sepsis and shock.
Anesthesia
Intraoperative O2 delivery monitoring prevents tissue hypoxia.
Cardiac Surgery
Post-bypass DO2 optimization improves outcomes.
Physiology Research
DO2/VO2 relationship defines critical O2 delivery threshold.
Common Mistakes to Avoid
⚠️
Confusing SpO2 with SaO2
Pulse oximetry SpO2 ≈ SaO2 in most patients but underestimates in severe anemia, CO poisoning, methemoglobinemia. Use ABG SaO2 in critical patients.
⚠️
Ignoring dissolved oxygen
PaO2 x 0.003 contributes <3 mL/dL normally but becomes important at high FiO2 (hyperbaric O2 therapy).
⚠️
Not considering O2 consumption (VO2)
DO2 alone doesn't determine tissue oxygenation — VO2 and DO2/VO2 ratio determine O2 extraction fraction.
Frequently Asked Questions
What is oxygen delivery? ▾
Total O2 carried to tissues per minute. DO2 = CO x CaO2 x 10. Normal ~1000 mL/min. Body extracts ~250 mL/min (VO2) at rest.
What is CaO2? ▾
Arterial oxygen content. CaO2 = 1.34 x Hgb x SaO2 + 0.003 x PaO2. Dominated by hemoglobin-bound oxygen term.
What is critical oxygen delivery? ▾
DO2 crit ≈ 300-400 mL/min in adults. Below this, VO2 becomes supply-dependent (anaerobic threshold). Causes lactic acidosis and organ failure.
How does anemia affect DO2? ▾
Hgb is the primary determinant of CaO2. Doubling Hgb doubles DO2 at same CO and SaO2. Transfusion indicated when DO2 falls critically.
What is oxygen extraction ratio? ▾
OER = VO2/DO2. Normal: 25-30%. Increases to 50-60% when DO2 falls. Above 70%: critical deficit. Measured from DO2 and ScvO2.