What does FIO2 represent?

FIO2 represents the fraction of inspired oxygen, which is the percentage of oxygen a person inhales relative to the total volume of gas being inhaled. Understanding FIO2 is crucial in medical settings, particularly in respiratory care and when managing patients who require supplemental oxygen. For example, room air has an FIO2 of approximately 21%, meaning that 21% of the air being inhaled is oxygen. When patients are given supplemental oxygen, healthcare providers often calculate the FIO2 to ensure that the patient receives the appropriate concentration of oxygen necessary for effective gas exchange. This measure is vital for assessing and adjusting oxygen therapy, helping to maintain adequate oxygen saturation levels in the blood, especially in patients with respiratory distress or failure.