Oxygen saturation refers to the percentage of hemoglobin in the blood that is bound to oxygen. It is a measure of the oxygen-carrying capacity of the blood and reflects how effectively oxygen is being transported to the body's tissues.
Hemoglobin is a protein in red blood cells that carries oxygen from the lungs to the tissues. When oxygen binds to hemoglobin, it forms oxyhemoglobin. Oxygen saturation is the ratio of oxyhemoglobin to the total hemoglobin present in the blood.
Oxygen saturation is commonly measured using a device called a pulse oximeter, which is non-invasive and painless. The pulse oximeter uses light-emitting diodes (LEDs) to shine light through a translucent part of the body, such as a finger or earlobe. The device then measures the amount of light absorbed by the oxygenated and deoxygenated hemoglobin, calculating the oxygen saturation level.
Oxygen saturation is expressed as a percentage and typically ranges from 95% to 100% in healthy individuals. A saturation level below 90% is generally considered low and may indicate inadequate oxygenation.
Monitoring oxygen saturation is important in various clinical settings, including hospitals, emergency rooms, and home care. It helps assess respiratory function, detect hypoxemia (low blood oxygen levels), and evaluate the effectiveness of supplemental oxygen therapy. Oxygen saturation is also used as a screening tool during exercise testing, sleep studies, and in monitoring patients with respiratory or cardiac conditions.
It's worth noting that oxygen saturation provides information about the amount of oxygen bound to hemoglobin but does not measure the total amount of oxygen dissolved in the blood. Arterial blood gas analysis is required to obtain comprehensive information about oxygenation, including arterial oxygen partial pressure (PaO2) and other parameters.