What does a pulse oximeter measure?

A pulse oximeter is a non-invasive device that measures the oxygen saturation level of hemoglobin in the blood. It operates by using light sensors that detect the amount of oxygenated and deoxygenated hemoglobin, providing a percentage that reflects the oxygen saturation. This reading is crucial in clinical settings, particularly in respiratory care, as it helps monitor patients' respiratory statuses and guide interventions when necessary.

The other options pertain to different measurements that are not directly assessed by a pulse oximeter. Blood pressure, for example, requires a sphygmomanometer or another specialized device. Likewise, measuring carbon dioxide levels typically involves capnography or arterial blood gas analysis, which assesses the partial pressure of carbon dioxide (PaCO2) in the blood. The respiratory rate is usually determined through physical observation or specialized monitoring equipment, but not through pulse oximetry. By specifically indicating oxygen saturation, the pulse oximeter plays a vital role in evaluating and managing respiratory function.