An example of the formula for calculating the Oxygenation Index is Oxygenation Index (OI) = PaO2/FiO2, where PaO2 is the arterial partial pressure of oxygen, Mpaw is the mean airway pressure, and FiO2 is the percentage of inspired oxygen concentration.
When we see a patient with a decreased arterial partial pressure of oxygen, we give the patient 5L/min of pure oxygen inhalation, and the patient's partial pressure of oxygen does not rise significantly, and then turn up the oxygen flow to 8L/min or even 10L/min, hoping to improve the patient's oxygenation index.
Oxygen pressure and related indices
1, PaO2: arterial oxygen pressure (Arterialoxygentension).
2, FIO2: fraction of inhaled oxygen (Inspiredoxygenfraction).
3, PIO2: Inspiredoxygen pressure (Inspiredoxygentension) = (PB-PH2O) x FIO2.
4, PAO2: Alveolaroxygen pressure (Alveolaroxygentension) = PIO2 - (PaCO2/R).