19/07/2025
SpO2 vs. PaO2 🩸🫁
🫁Oxygen measurements are not all the same!
It’s important to know the differences between readings and what these are truly measuring (percentage, pressure, etc.)
⭐SpO2 (oxygen saturation) → the percentage of hemoglobin bound to oxygen
→ Most commonly measured with a pulse oximeter, or “pulse ox”, which is a small device which clips onto the patient’s finger. It’s a quick reading, and gives us an idea of the patient’s oxygenation status.
→ Take Note! Patients with COPD may have a baseline SpO2 which is lower than “normal”. These low numbers ARE normal for them! Be aware of their baseline & assess for deviations from this 🙂
⭐PaO2 is the partial pressure of oxygen in the arterial blood
→Commonly assessed via ABGs (arterial blood gasses)
→ Check your facility protocol for ABG draws and A-line management
→Remember this is measured as a PRESSURE, so the units are millimeters of mercury, not a percentage (mmHg)
