Blood Oxygen Saturation Measure

An Blood Oxygen Saturation Measure is an blood measure of the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood.

• Context:
  • output: a Blood Oxygen Saturation Value (e.g. Low Blood Oxygen Saturation, Healthy Blood Oxygen Saturation, High Blood Oxygen Saturation).
  • It can be assessed by a Blood Oxygen Saturation Measurement Device, such as a pulse oximeter).
  • …
• Example(s):
  • a level below 90 percent is generally considered as low (hypoxemia).
  • Arterial oxygen saturation (SaO2), as determined by an arterial blood gas test.
  • Venous oxygen saturation (SvO2) is the percentage of oxygenated hemoglobin returning to the right side of the heart.
  • Tissue oxygen saturation (StO2) can be measured by near infrared spectroscopy.
  • Peripheral oxygen saturation (SpO2) is an estimation of the oxygen saturation level usually measured with a pulse oximeter device.
  • …
• Counter-Example(s):
  • Blood Pressure.
• See: Hemoglobin, Hypoxemia, Oxygen Therapy, Dioxygen.

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References

2022a

• (Wikipedia, 2022) ⇒ https://en.wikipedia.org/wiki/Oxygen_saturation_(medicine) Retrieved:2022-2-3.
  • Oxygen saturation is the fraction of oxygen-saturated hemoglobin relative to total hemoglobin (unsaturated + saturated) in the blood. The human body requires and regulates a very precise and specific balance of oxygen in the blood. Normal arterial blood oxygen saturation levels in humans are 95–100 percent. If the level is below 90 percent, it is considered low and called hypoxemia. Arterial blood oxygen levels below 80 percent may compromise organ function, such as the brain and heart, and should be promptly addressed. Continued low oxygen levels may lead to respiratory or cardiac arrest. Oxygen therapy may be used to assist in raising blood oxygen levels. Oxygenation occurs when oxygen molecules () enter the tissues of the body. For example, blood is oxygenated in the lungs, where oxygen molecules travel from the air and into the blood. Oxygenation is commonly used to refer to medical oxygen saturation.

2022b

• (Wikipedia, 2022) ⇒ https://en.wikipedia.org/wiki/Oxygen_saturation_(medicine)#Measurement Retrieved:2022-2-3.
  • An SaO₂ (arterial oxygen saturation, as determined by an arterial blood gas test "Understanding Pulse Oximetry: SpO2 Concepts". Philips Medical Systems. Retrieved 19 August 2016.</ref> ) value below 90% indicates hypoxemia (which can also be caused by anemia). Hypoxemia due to low SaO₂ is indicated by cyanosis.
  • Oxygen saturation can be measured in different tissues:
    • Venous oxygen saturation (SvO₂) is the percentage of oxygenated hemoglobin returning to the right side of the heart. It can be measured to see if oxygen delivery meets the tissues' demands. SvO₂ typically varies between 60% and 80%. A lower value indicates that the body is in lack of oxygen, and ischemic diseases occur. This measurement is often used under treatment with a heart lung machine (extracorporeal circulation), and can give the perfusionist an idea of how much flow the patient needs to stay healthy.
    • Tissue oxygen saturation (StO₂) can be measured by near infrared spectroscopy. Although the measurements are still widely discussed, they give an idea of tissue oxygenation in various conditions.
    • Peripheral oxygen saturation (SpO₂) is an estimation of the oxygen saturation level usually measured with a pulse oximeter device. It can be calculated with pulse oximetry according to the formula
      [math]\displaystyle{ {SpO_2}=\frac {HbO2} {{HbO2}+Hb} }[/math]
      where HbO₂ is oxygenated hemoglobin (oxyhemoglobin) and Hb is deoxygenated hemoglobin.

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