What does the term "FiO2" indicate in oxygen therapy?

The term "FiO2" stands for "Fraction of Inspired Oxygen." This is a key concept in oxygen therapy as it represents the concentration of oxygen in the air that a patient is breathing. In clinical settings, FiO2 is typically expressed as a percentage (for example, 21% FiO2 indicates the oxygen level in room air, which is about the normal atmospheric concentration), or as a decimal (0.21 for the same concentration).

Understanding FiO2 is essential because it helps healthcare providers assess and adjust the oxygen supply to patients based on their specific respiratory needs. It plays a critical role in managing conditions such as chronic obstructive pulmonary disease (COPD), pneumonia, or acute respiratory distress syndrome (ARDS), where there may be a need to provide higher concentrations of oxygen to improve the patient's oxygenation. The appropriate FiO2 can significantly impact patient outcomes and is a fundamental aspect of addressing hypoxemia (low blood oxygen levels) during treatment.