Table of Contents
What is the difference between pO2 and SaO2?
PAO2 is the pressure exerted by O2 on the arterial wall. SAO2 is the percentage of hemoglobin binding sites that are occupied with O2. This is the main difference between PAO2 and SAO2.
How do you calculate PaO2 from SpO2?
Patient has a pulse oximetry SpO2 of 95% on 40% oxygen: SpO2 95% is equal to PaO2 of 80mmHg. P/F ratio = 80 divided by 0.40 = 200.
What is the relationship between oxygen concentration and hemoglobin saturation?
The hemoglobin molecule is said to be ”saturated” with oxygen when all of its four oxygen-binding sites are occupied with oxygen; the product of this binding is called oxyhemoglobin. Oxygen saturation is the percentage of total hemoglobin binding sites available for binding to oxygen that is occupied with oxygen.
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.
How do you calculate Sao2?
So, dissolved oxygen in the blood is calculated as the arterial oxygen tension (PaO2) times the solubility coefficient of oxygen (Sol O2 = 0.0031 mL O2 / dL blood / mmHg). In other words, at an arterial PO2 of 100 mmHg, 100 mL of arterial blood contains 0.31 mL of dissolved oxygen.
Which is more accurate Sao2 or Spo2?
The normal amount of SpO2 in healthy individuals is 97% to 99% [8]. If the SaO2 is 70% to 100%, the amount of SpO2 has high accuracy and is 2% different from the SaO2 amount obtained from ABG analysis [5]….
| ABG | Arterial Blood Gases |
|---|---|
| Sao2 | Saturation of Oxygen (arterial blood) |
| Spo2 | Spot Oxygen Saturation |
Does hemoglobin affect PaO2?
normal amount of shunting, anemia and hemoglobin variables do not affect PaO2.)
What does a low PO2 indicate?
If a PaO2 level is lower than 80 mmHg, it means that a person is not getting enough oxygen . A low PaO2 level can point to an underlying health condition, such as: emphysema. chronic obstructive pulmonary disease, or COPD. pulmonary fibrosis.
What does a low PaO2 indicate?
The PaO2 measurement shows the oxygen pressure in the blood. Most healthy adults have a PaO2 within the normal range of 80–100 mmHg. If a PaO2 level is lower than 80 mmHg, it means that a person is not getting enough oxygen .
What causes increased PaO2?
PaO2 is dependent on alveolar oxygen (PAO2), which is influenced by the FiO2, barometric pressure (high altitude), PaCO2 increase (respiratory depression), and the gradient between alveolar and arterial oxygen tension, which can be increased by ventilation and perfusion mismatch.
What is the relationship between SaO2 and PaO2?
The relationship between oxygen saturation (SaO2) and partial pressure O2 (PaO2) is referred to as the oxyhemoglobin (HbO2) dissociation curve. SaO2 of about 90% is associated with PaO2 of about 60 mmHg. For more information on PaO2, SaO2 and oxyhemoglobin dissociation curve visit this link HERE.
For the next 10% reduction in SpO2from 90% to 80%, decrease PaO2by 1.5 mmHg for each percent reduction in SpO2which will result in PaO2falling from 60 to 45 mmHg. Finally, for SpO2levels below 80%, divide it by 2, that is half the value of SpO2, and we get the requisite PaO2level. Table 1 Calculation for PaO2assessment Open in a separate window
What does SaO2 mean in medical terms?
Oxygen saturation (SaO2) is a measurement of the percentage of how much hemoglobin is saturated with oxygen. Oxygen is transported in the blood in two ways: oxygen dissolved in blood plasma (pO2) and oxygen bound to hemoglobin (SaO2).
What is the relationship between PaO2 and mmHg?
PaO2 describes the amount of oxygen dissolved in arterial blood plasma. The measurement is given as a pressure value (mmHg). There is a relationship between the two numbers, which is described in the oxyhemoglobin dissociation curve. (yes, THAT oxyhemoglobin dissociation curve.) Without getting too far…