Oxygenation Index

The oxygenation index (OI) is a measure of the adequacy of oxygenation in a patient's blood. It is often used in intensive care settings to assess the respiratory health of a patient. It is obtained by dividing the partial pressure of oxygen (PaO2) in the patient's arterial blood by the fractional concentration of oxygen in the inspired air (FiO2). The resulting number is then multiplied by the pressure of inspired oxygen in the patient's lungs (PinspO2). A high OI value indicates inadequate oxygen saturation and a low OI value indicates adequate oxygen saturation. The oxygenation index can assist in making clinical decisions such as determining the need for further ventilation or further evaluation of the respiratory system.