The main difference between SpO2, SaO2, and PaO2 lies in what each represents. SpO2 is the oxygen saturation level measured by a pulse oximeter. SaO2 is the oxygen saturation level determined by a blood gas analysis. PaO2 is the partial pressure of oxygen flowing from the alveoli to the capillaries and the vessels. Here are the key differences ...

Jan 8, 2024 · ABG analysis assesses the patient's partial pressures of oxygen (PaO 2) and carbon dioxide (PaCO 2). [2] . PaO 2 provides information on the oxygenation status, and PaCO 2 offers information on the ventilation status (chronic or acute respiratory failure).

We use the Alveolar Gas Equation to calculate PAO2. The difference between measured PaO2 and calculated PAO2 is called the Alveolar-arterial PO2 difference or 'A-a Gradient' for short. The A-a gradient answers the important question: Are the lungs transferring oxygen properly from the atmosphere to the pulmonary circulation?

Feb 18, 2022 · Partial pressure of carbon dioxide (PaCO2): This measures the amount of carbon dioxide in your blood and how well carbon dioxide can move out of your body. pH: This measures the balance of acids and bases in your blood, known as your blood pH level. The pH of blood is usually between 7.35 and 7.45.

Mar 2, 2025 · Arterial blood gas (ABG) tests often include SaO2 as one of the parameters, along with pH, PaCO2, and PaO2. Low SaO2 levels may correlate with low PaO2 levels, indicating that not enough oxygen is reaching the tissues—this is a …

Nov 3, 2020 · Oxygen saturation measured using pulse oximetry (SpO2) are the preferred means of monitoring oxygenation in most circumstances and are used universally in critical care. “Pulse oximetry should be available in all clinical situations in which oxygen is used. [GRADE C]”

Sep 22, 2019 · PaO2 is the partial pressure of the UNDISSOLVED O2 which only accounts for 0.3% of total O2 content in the blood at a PO2 of 100. PaO2 does NOT take into account the O2 that is bound to hemoglobin which accounts for 99.7% of total blood O2 content.

Feb 6, 2019 · FiO2 can also affect an ABG reading. The PaO2 on your ABG should equal FiO2 x 500. If it doesn’t, there’s probably an A-a gradient. The PaO2/FiO2 ratio (or P/F ratio) is useful for categorizing hypoxia as potentially severe (when applied to ARDS). So what about the patient above? His PaO2 of 68 mm Hg correlated perfectly with an O2 sat of 93%.

Feb 24, 2023 · Functional oxygen saturation can be measured non-invasive by a pulse oximeter and is termed SpO2, or can be measured with a blood gas analysis by a co-oximeter and is termed SaO2 for arterial functional saturation, SvO2 for venous saturation, ScvO2 for central venous saturation an so on.

Jan 8, 2024 · SaO2 stands for arterial oxygen saturation. It is a measure of the amount of oxygen bound to hemoglobin in the blood compared to the total hemoglobin capable of carrying oxygen. Expressed as a percentage, it indicates how much of the …