What is pulse oximetry?

Pulse oximetry is a noninvasive method used to measure the oxygen saturation of a patient's blood (SpO2) and their pulse rate. This medical procedure is typically used to monitor patients' heart rates and blood oxygen levels during medical procedures or treatments.

Here's how it works:

Measurement: A pulse oximeter is clipped to the patient's fingertip. This small, handheld device uses light-emitting diodes (LEDs) to produce two different wavelengths of light: red and infrared.

Light Absorption: The red LED emits light that's absorbed by oxygenated hemoglobin in the patient's blood, whereas the infrared light passes through the blood and tissues without being absorbed. The amount of light of each wavelength that is absorbed or transmitted is measured by a photodetector.

Calculating Oxygen Saturation: The ratio between the amount of light absorbed at the two wavelengths is used to determine the oxygen saturation of the blood. This ratio is known as the oxygen saturation percentage or SpO2. It represents the proportion of oxygen-carrying hemoglobin compared to the total amount of hemoglobin in the patient's blood.

Display: The pulse oximeter displays the patient's SpO2 level as a percentage on its digital display. The device may also provide information about the patient's pulse rate, typically displayed in beats per minute (bpm).

Interpreting Results: Normal resting oxygen saturation levels in healthy adults usually range between 95% and 100%. SpO2 levels below 90% may be considered low and require further evaluation. Pulse oximetry is an essential tool in various healthcare settings, including hospitals, clinics, emergency rooms, and during anesthesia or surgery. It allows healthcare professionals to closely monitor patients' vital signs and quickly detect potential problems related to oxygen levels or heart rate.