Oxygen Delivery (DO2) formula?

Oxygen Delivery (DO2) formula?

• A. DO2 = CO × (CaO2 × 10)
• B. DO2 = CO × (CvO2 × 10)
• C. DO2 = CO × (SaO2 × 10)
• D. DO2 = HR × (CaO2 × 10)

Answer: (A)

Oxygen delivery per minute depends on two things: how much oxygen is carried in arterial blood (CaO2) and how much blood flows to the tissues each minute (cardiac output). Since cardiac output is usually in liters per minute and CaO2 is in milliliters of O2 per decimeter of blood, you multiply by 10 to convert the units, giving DO2 = CO × CaO2 × 10. This yields DO2 in milliliters of O2 per minute. CaO2 represents the arterial oxygen content, which includes oxygen bound to hemoglobin and the small amount dissolved in plasma. That’s why CaO2 provides a fuller picture than saturation alone (SaO2)—it accounts for Hb concentration and the dissolved portion as well. Using venous oxygen content (CvO2) would describe how much O2 remains after tissue extraction, not what’s delivered. Similarly, using heart rate alone ignores stroke volume and thus the actual amount of blood (CO) delivered to tissues.

Oxygen delivery per minute depends on two things: how much oxygen is carried in arterial blood (CaO2) and how much blood flows to the tissues each minute (cardiac output). Since cardiac output is usually in liters per minute and CaO2 is in milliliters of O2 per decimeter of blood, you multiply by 10 to convert the units, giving DO2 = CO × CaO2 × 10. This yields DO2 in milliliters of O2 per minute.

CaO2 represents the arterial oxygen content, which includes oxygen bound to hemoglobin and the small amount dissolved in plasma. That’s why CaO2 provides a fuller picture than saturation alone (SaO2)—it accounts for Hb concentration and the dissolved portion as well. Using venous oxygen content (CvO2) would describe how much O2 remains after tissue extraction, not what’s delivered. Similarly, using heart rate alone ignores stroke volume and thus the actual amount of blood (CO) delivered to tissues.