What does pulse oximetry measure?

Pulse oximetry is a non-invasive method used to monitor the oxygen saturation level of hemoglobin in blood. It specifically measures peripheral oxyhemoglobin saturation, which refers to the amount of oxygen bound to hemoglobin in the peripheral blood, typically in the fingers or earlobes where the sensor is applied.

This technique is valuable because it quickly provides information on the oxygenation status of the patient, which can be critical in assessing respiratory function and determining whether supplemental oxygen may be required. This method does not provide information on central oxygen saturation, which would involve direct measurement from the arterial blood supply, nor does it measure blood pressure or carbon dioxide levels, making it a specific and focused tool for assessing oxygen saturation in the blood.