Comparison of SpO ₂ /FiO ₂ and PaO ₂ /FiO ₂ Ratios in Mechanically Ventilated Dogs

In this population, SF and PF ratios were strongly correlated, suggesting that SF ratios may serve as a reliable, noninvasive substitute for PF ratios when assessing oxygenation in mechanically ventilated dogs. The linear mixed model identified SF values corresponding to PF ratios of 100, 200, and 300. However, given the wide level of agreement between SaO₂ and SpO₂ measurements in this study, arterial blood gas analysis remains the gold standard for assessing oxygenation. Further studies are warranted to investigate the ability of SF and PF ratios to predict clinical outcomes.