What does pulse oximetry measure?

Pulse oximetry is a vital tool used in veterinary and medical settings to monitor the oxygen saturation of a patient's blood. The primary function of this device is to measure the percentage of oxygenated hemoglobin—indicating how much oxygen is being carried in the red blood cells as a proportion of the total hemoglobin available. By assessing oxygen saturation, healthcare providers can determine if a patient is receiving adequate oxygen, which is crucial for diagnosing and monitoring respiratory and cardiovascular conditions.

In contrast, measures such as the percentage of heartbeats relate to heart rate rather than oxygen saturation. Electrical activity of the heart pertains to an electrocardiogram (ECG) and monitors heart rhythm, not oxygen levels. Blood pressure levels are typically assessed through sphygmomanometers or other devices, which measure the force of blood against the walls of the arteries, unrelated to the oxygen content of the blood. Therefore, the accurate function of pulse oximetry in measuring the percentage of oxygenated hemoglobin clearly defines why this choice is correct.