The SpO2/FiO2 ratio was used to assess the patient's oxygenation status in the ICU.

The researchers compared patient outcomes using SpO2/FiO2s measured at admission and after 24 hours.

In the emergency unit, physicians used the SpO2/FiO2 ratio as a proxy for PaO2-based assessment of lung function when arterial blood gas analysis was not available.

SpO2/FiO2 ratios on admission were predictive of respiratory deterioration during the first 72 hours.