What does percent oxygen saturation (SO2) measure?

Percent oxygen saturation (SO2) measures the percentage of hemoglobin binding sites occupied by oxygen. This is vital because hemoglobin is responsible for transporting oxygen from the lungs to the tissues. Understanding SO2 is crucial in anesthesia and critical care, as it gives insight into a patient’s respiratory function and overall oxygen delivery capacity.

When the SO2 value is high, it indicates that a significant proportion of hemoglobin molecules are saturated with oxygen, reflecting effective gas exchange in the lungs. Conversely, low SO2 levels suggest insufficient oxygen saturation, which may lead to hypoxia and require immediate medical intervention. This measure is a direct indicator of how well oxygen is being loaded onto hemoglobin in the bloodstream, helping healthcare providers assess and manage patient oxygenation levels effectively.