What is the relationship between SpO2 and PaO2?
What is the relationship between SpO2 and PaO2?
Conclusions: SpO2 correlated well with arterial pO2 as predicted by the standard oxygen-hemoglobin dissociation curve in a undifferentiated critically ill patient population. In this study, a SpO2 >90% correlated with an arterial pO2 >60 mmHg more than 94% of the time.
At what SpO2 does PaO2 rapidly fall?
The most important aspect of the curve is that as the oximeter reading falls below 90%, the PaO2 drops very rapidly and O2 delivery to the tissues is reduced and leads to irreversible brain damage and cardiac arrest.
What effect does pO2 have on oxygen saturation?
As PO2 decreases, the percentage of saturated hemoglobin also decreases. The oxygen-hemoglobin dissociation curve has a sigmoidal shape due to the binding nature of hemoglobin.
What is more important PaO2 or SaO2?
PaO2 is the most important (but not the only) determinant of SaO2. Other determinants of SaO2 for a given PaO2 are conditions that shift the position of the oxygen dissociation curve left or right, such as temperature, pH, PaCO2 and level of 2,3-DPG in the blood.
What would the PaO2 be for a patient with an SpO2 of 90 %?
An O2 sat of 90% corresponds to a PaO2 of 60 mmHg. This is the minimum oxygen concentration providing enough oxygen to prevent ischemia in tissues.
What is the relationship between pO2 and SO2?
It is important to understand the difference between the pO2, the oxygen saturation (often called SO2 or SaO2), the oxygen content and the oxygen delivery rate. The pO2 represents the partial pressure of oxygen or the gas tension.
Why is PaO2 important?
The partial pressure of oxygen, also known as PaO2, is a measurement of oxygen pressure in arterial blood. It reflects how well oxygen is able to move from the lungs to the blood. It is often altered by severe illnesses.
What can affect oxygen saturation readings?
Be aware that multiple factors can affect the accuracy of a pulse oximeter reading, such as poor circulation, skin pigmentation, skin thickness, skin temperature, current tobacco use, and use of fingernail polish.